GroupDIY

Project Specific Discussions => Dynamic Processors => Topic started by: mnats on December 28, 2006, 10:31:50 PM

Title: [BUILD] 1176LN Rev D DIY
Post by: mnats on December 28, 2006, 10:31:50 PM
Having trouble with this build? Read the 1176 FAQ (http://mnats.net/1176_FAQ.html).

(http://mnats.net/images/1176_rev_d_pcb_sm.jpg) (http://mnats.net/images/1176_rev_d_pcb.jpg)
(Click for really big pics)
There didn't seem to be much interest in this when I raised the idea on another thread but I thought I would post my holiday DIY anyway. I started out simply putting the class A output stage in place of one on my version of Jakob's G1176 board but quickly decided to do a whole new layout, incorporating the discrete meter circuit of the earlier revisions as well (and all the earlier component designations).

(http://mnats.net/images/1176_rev_d_testing_small.jpg) (http://mnats.net/images/1176_rev_d_testing.jpg)
I did a double-sided home etch, fixed a few minor errors and have it up and running into some CJ iron (through a capacitor to block the DC). Everything seems to work just fine. Just waiting on output transformers from Andrew at Purple so I can hook up the feedback and DC balance windings, but I don't anticipate any problems as the amplifier seems to be working well even without the transformer feedback.

I'll post some PDFs of the corrected layout if anyone is interested. Sorry, I tried to make it single-sided but it was just too hard for me. Anyway, the ground plane makes it nice and quiet, even outside of a case.

*edit: Some documentation including self-etch files can be found on my site (http://mnats.net/1176_revision_d.html).
Please download the 1176LN manual from the JBL Pro Site (http://www.jblproservice.com/navigation/Vintage%20JBL-UREI%20Electronics.html).
Title: 1176LN Rev D DIY
Post by: dripelectronics on December 29, 2006, 01:30:44 AM
that looks great ! :shock:

it's nice to see another pcb designer slave end up with some
nice results ,

i feel ya on the one sidded board things ,
turns it into the greatest puzzel ever.

best of luck ,

g,
Title: 1176LN Rev D DIY
Post by: Geert Heyrman on December 29, 2006, 02:52:55 AM
Hi Mnats,

That looks realy nice.  :thumb:

Geert
Title: 1176LN Rev D DIY
Post by: chrissugar on December 29, 2006, 03:27:10 AM
Very nice looking PCB Mako.  :thumb:

chrissugar
Title: 1176LN Rev D DIY
Post by: Lowfreq on December 29, 2006, 04:22:20 AM
Awesome!!! :green:

Thats an impressive holiday project. :shock:

Quote from: "mnats"
There didn't seem to be much interest in this when I raised the idea on another thread
I must have missed that thread, coz this has my interest straight away!!!! :thumb:
Title: 1176LN Rev D DIY
Post by: safe as milk on December 29, 2006, 05:32:56 AM
hi
i missed that too, the rev d pair is a great idea.
tidy layout too :thumb:

what are you going to use for input iron?
Title: 1176LN Rev D DIY
Post by: Rob Flinn on December 29, 2006, 05:34:43 AM
Greg

That looks really good !   Nice & compact.

One thing.  I'm wondering why you didn't take the opportunity to use 25 turn trimmers, which make the 1176 much easier to set up?
Title: 1176LN Rev D DIY
Post by: flaheu on December 29, 2006, 07:11:06 AM
Hello,

I've completly missed this thread :sad:  
If I knew, I would have wait some times before I order your G1176 Rev H !
They are not stuffed yet  :wink:
This new board seems to be a nice comromise between G1176 and the now defunct Purple kit.
I hope you'll make your pcb available soon

Great job :thumb:  :thumb:
Title: 1176LN Rev D DIY
Post by: radiance on December 29, 2006, 07:16:08 AM
It's a work of art!

All these transistors beautifully lined up and all.....
Title: 1176LN Rev D DIY
Post by: matthias on December 29, 2006, 07:25:07 AM
definately !  very nice layout!

for the meter circuit I would go for a classic meter buffer as purple did that in their mc77

I recognize a small drop in output level when the 1176 is switched to +4 or +8
Title: 1176LN Rev D DIY
Post by: ChrioN on December 29, 2006, 08:28:56 AM
Looks almost completely different, in a good way  :thumb:
I want one of those  :green:
Title: 1176LN Rev D DIY
Post by: raysolinski on December 29, 2006, 09:01:25 AM
I'm in for one when you do a run...hey that rhymes!

Cheers,
Ray
Title: 1176LN Rev D DIY
Post by: Barish on December 29, 2006, 02:07:42 PM
That's a damn neat design, dude. Congrats  :thumb:

I'd be interested in a pair once you 've finished it as well.

May I also ask your help once my brother and I get this flexi-76 challenge working too? It could be more practical for we are using your other 76 board as prototype. We still have a wee while to finish it, though. Not so easy as it seems, a lot of mechanical work to be done for the servomotor positionings and adjustments and all.

Happy new year.

Mach
Title: 1176LN Rev D DIY
Post by: edanderson on December 29, 2006, 02:28:04 PM
Quote from: "Rob Flinn"
Greg

That looks really good !   Nice & compact.

One thing.  I'm wondering why you didn't take the opportunity to use 25 turn trimmers, which make the 1176 much easier to set up?


i second this idea.  multiturn trimmers make a big difference; hopefully your new layout can accept a few kinds of trimpots.  i would also change the selected (usually around 1k) GR meter calibration resistor to a 2kohm trimmer in series with a 100ohm resistor.  this makes the GR meter calibration easier.

i don't suppose there is room for the pcb mount input transformer?

board looks very nice, btw.

everyone should realize that for max performance you'll need the specialized output transformer.  a simple gapped 1:1 could probably substitute acceptably.  purple will not be selling the output transformers after the new year, but i've posted the cinemag part number before.  if there is enough interest, perhaps i can arrange some kind of group order.

ed
Title: 1176LN Rev D DIY
Post by: SJakobsen on December 31, 2006, 07:10:17 AM
Hi MNats

That look's real great, and a nice layout too  :grin:

I may be interested in buying one of your PCB's when ready.
Title: 1176LN Rev D DIY
Post by: joe-electro on December 31, 2006, 01:36:36 PM
Count me in for four boards, once you feel they're production-ready.

Thanks!

Happy New Gear - er- New Year!!!
Title: 1176LN Rev D DIY
Post by: mnats on January 03, 2007, 03:48:10 AM
...just got back from a Melbourne New Year - fireworks off the tops of buildings  :shock: - didn't realize there was any interest in this project. Guess now that the Purple kits are over there might be more folks interested...

It's not too difficult to do a single-sided board but it would disturb some of my neatly placed components. I spent a lot of time getting things to look nice - my wife thinks it's a very strange obsession.

I made the physical layout of the board follow the drawing of the schematic very closely so the signal flow is very easy to visualize. Should make it easier to troubleshoot as well.

The trimmer footprints will all accept precision types as there are holes for almost every type. Didn't find it that difficult to do the adjustments though with cheap single twist ones.

And the trimmer across the diff pair in the meter driver is already done. I got frustrated when I didn't have a 1.68k resistor so I changed the layout to fit the trim pot.

I could make room for just about anything on the board including the input transformer, but thought it might be better to leave it off-board so there are more options. Now that I think of it though, if there is a standard transformer people are using and it has pins it might make contruction easier if there is a quick way to mount it.

What sort of iron are people using in their Purples?
Title: 1176LN Rev D DIY
Post by: Shenes on January 03, 2007, 04:32:25 AM
Hi,

I'm thinking of building a couple of G1176 based on boards from Mnats. But this thread is making me a bit confused. The current version for sale in the black market is the rev J and this new version is rev D? Why "D", am I missing something? In what way is this new version different?

I'm planning to use a older Lundahl LL4602 output tranformer for my build and possibly use a LL4601 as input transformer. (The LL4601 is not 100% pin compatible with the 1540, which would require some tweaking.) I'm also planning on building dual units in one box. Would you say that I'd be better of building from the rev J boards?

Last, I'm a new member of this forum and is impressed with all the creativity,  knowledege and accomplishments of the members, inspiring!

regards,
johannes
Title: 1176LN Rev D DIY
Post by: Rob Flinn on January 03, 2007, 04:36:06 AM
Quote from: "mnats"

What sort of iron are people using in their Purples?


I would guess that many people are using the iron that Andrew supplies with the kits.
Title: 1176LN Rev D DIY
Post by: mnats on January 03, 2007, 05:12:19 AM
Quote from: "Rob Flinn"
I would guess that many people are using the iron that Andrew supplies with the kits.

You are rough on a guy who just drove 700 kms. Right, the Altran C-3837-1. Can't find any info about it doing a search so maybe it's a custom job? Anyway, I'll probably forget about on-board transformer mounting - the board suits my purposes as is and it's not intended as a G1176 replacement by any stretch. This project will never have the sort of popularity as Jakob's G1176 I'm sure, but I'll post some layouts and have a small batch made just the same.

Thanks for the compliments on the layout, folks. I had a lot of fun doing it, aside from getting the pinout on the FETs wrong...
Title: 1176LN Rev D DIY
Post by: Lowfreq on January 03, 2007, 05:46:36 AM
Quote from: "Shenes"
Hi,

I'm thinking of building a couple of G1176 based on boards from Mnats. But this thread is making me a bit confused. The current version for sale in the black market is the rev J and this new version is rev D? Why "D", am I missing something? In what way is this new version different?

Mako can probably fill you in on this better than me, but the Rev D refers to one of the models of the origional units. There are a few different versions out there. The G1176 is based off a Rev F or G I think?

There's a few threads around here explaining the differences of the different revs.

Quote from: "edanderson"
oh dear, has everyone now done the homework that jens assigned? i don't like to see this question come up over and over either, but it is confusing. here are some cliffs notes that i hope will be helpful:

the rev A and B units (blue stripe) have a total of ~50db of system gain, with a 5db lower threshold point than the rev C-F (black face) which have ~45db of system gain (the F has a class AB output amp, C-E class A). this means that if you were to turn the input knob to the same place on both a blackface and a bluestripe, and send them the same signal, the blue stripe would go into action first. so you would naturally set the input control lower on a blue stripe (to get a similar threshold), and that is what the extra 5db of gain is for... to make up for the extra attenuation at the input.

the purple and the UA are both based on the rev D/E units, so they both should have 45db of system gain. the purple MC76 and MC77 are tested for that before they leave the shop. the earlier and perhaps present UA units probably do, but they had that "mid era" where they re-did the front end, so who knows for sure.

the g1176 is based on the later rev G (the first silverface). revs F-H used an output transformer (B11148) that was configured as 1:3.5 (10db gain) for the domestic market or 1:1 (unity gain) for export to europe. the gyraf PCB uses a lundahl output as a 2:1 stepdown (6db loss). some people modified the PCB to reverse the transformer. the mnats PCB has options for various 1:2 stepup (6db gain) transformers. and the front end is either an opamp (rev G) or a bridging transformer before a pot, similar to the solution UA used in their "mid era" reissues (to be contrasted with an attenuator before the transformer, as in the rev F and earlier). finally, the threshold sensitivity is again different on the rev G, so the input knob settings do not translate well from a rev G to the D/E units.

ANYWAY, there are many options with the g1176, and yes you can make something mighty close to a rev G or even a rev F if you source all the right parts. i think experimentation is great and you can certainly make some interesting custom units. try a 31267 on the input and a lo2567 on the output, for example. or a cinemag version. or the OEP versions on the mnats PCB. lots of options.

that said, the class A output section of the rev D/E, as found in the purple units/kit, is different from what you can do with the g1176. and that is the sound some people are after.

ed


Here's the full thread wth a lot of discussion on the various 1176's
http://www.groupdiy.com/index.php?topic=18160&postdays=0&postorder=asc&highlight=1176&start=0

As for the rev J, it's Mako's own naming for his pcb version of the G1176(with some very handy additonal features)
Title: 1176LN Rev D DIY
Post by: Rob Flinn on January 03, 2007, 06:48:14 AM
Quote from: "mnats"
Quote from: "Rob Flinn"
I would guess that many people are using the iron that Andrew supplies with the kits.

You are rough on a guy who just drove 700 kms.


Sorry about that, but I thought I'd say it before anyone else got in with it !!
Title: 1176LN Rev D DIY
Post by: raysolinski on January 03, 2007, 09:12:52 AM
Go Mako Go!
I don't mind the off board transformers  :grin: ..Just curious, What type of output iron would we use? I am assuming without an output  cap we would need a gapped transformer?

Cheers.
Ray
Title: 1176LN Rev D DIY
Post by: flaheu on January 03, 2007, 02:30:48 PM
Quote
What sort of iron are people using in their Purples?


Personally, I would use the EDCOR that tony dB has tested recently:
 http://www.edcorusa.com/downloads/other_documents/XS1100_sheet.pdf

for output and maybe the usual suspect like OEP on input or maybe a Lundahl (like in the G1176.

I'ver already bought some iron's from tony and I should say I'm very pleased with them  

Mnats: again great job  :thumb:  :thumb:
I can not wait to buy 2 boards.
Title: 1176LN Rev D DIY
Post by: Rob Flinn on January 03, 2007, 03:04:37 PM
Quote from: "flaheu"
Quote
What sort of iron are people using in their Purples?


Personally, I would use the EDCOR that tony dB has tested recently:
 http://www.edcorusa.com/downloads/other_documents/XS1100_sheet.pdf

for output and maybe the usual suspect like OEP on input or maybe a Lundahl (like in the G1176.

I'ver already bought some iron's from tony and I should say I'm very pleased with them  

Mnats: again great job  :thumb:  :thumb:
I can not wait to buy 2 boards.


Yes, but you are totally forgetting that the class A UREI's need an output transformer with a tertiary feedback winding.  This is the main reason why there aren't too many clones out there  of the class A 1176.  This is why Jakobs board isn't cloning the class A 1176 in the first place.

I am quite interested to find out how well Mnats board works without this feedback winding in place.  Does it sound right ?  Iguess ultimately it oesn't matter too much whether it sounds exactly like a rev d/e, it is just another flavour
Title: 1176LN Rev D DIY
Post by: mnats on January 03, 2007, 08:42:15 PM
Too friggin' hot to venture into my workshop today. But when I had it hooked up to the CJ output transformer last week it sounded fine to me.

I'm no circuit reader like some of the experts around here but glancing at the schematic it seems as though there is the usual negative feedback happening in the circuit before the transformer and the tertiary winding simply applies overall feedback back to the first stage. Seems as though this might be to compensate mainly for distortion due to the transformer? Aren't there plenty of designs out there that don't bother compensating for the output transformer (like the later versions of the 1176 itself)?
(http://www.geocities.com/m_natsume/images/1176_revd_output.gif)
...edited to add schematic...

So maybe if you aren't too concerned about this overall feedback and use a gapped transformer or block the DC with a big cap you can be happy with an ordinary transformer. When the Purple 'reissue' shows up I will do a with and without test.

I'm surprised with all the people that appear to be interested that no one has encouraged edanderson with his group buy suggestion. Lots of folks seem happy with their Purples and with the same output iron this might be a simple way to get there now that the kit has been discontinued. Maybe he could even be pursuaded into doing an input transformer and attenuator group buy?
Title: 1176LN Rev D DIY
Post by: tommypiper on January 03, 2007, 09:14:21 PM
Mako,
great shtuff, man.  I've been waiting for this!  Dual in a 2U, yes!  

...edited...

cheers
Title: 1176LN Rev D DIY
Post by: kato on January 03, 2007, 09:50:04 PM
Gorgeous layout. It's art.
Your wife doesn't understand the obsession? I would think women are more attuned to the importance of pleasing visuals.

My wife once said (about a partially stuffed board, only resistors,) "I like the little blue beads."   :grin:
Title: 1176LN Rev D DIY
Post by: tommypiper on January 07, 2007, 12:34:36 AM
edited...  :grin:   showing my support.
Title: 1176LN Rev D DIY
Post by: Sleeper on January 07, 2007, 03:35:33 AM
http://cinemag.biz/application_notes/AN-106.pdf
this is pretty close I'll bet.  I'm sure they could do it. for a group order. I'd be in for two transformers and two boards.  

MNats. I have a few of your other boards.  are all the switching arrangements basically the same...  
seems like there aren't any major differences between the g1176 and the RevD, but i haven't looked too closely. Reckon you have.

 I'd be into a couple of those boards too... I haven't stuffed the revJ boards I bought from you, but this would be for my second dual 1176. a different flavor, and the purple style class A with the terteriary winding does sound different and I've been told "better-bigger-stronger " by mixers with a lot more hours on their ears than mine.

Why not right. :sam:  :thumb:
Kelly
Title: 1176LN Rev D DIY
Post by: mnats on January 07, 2007, 03:11:49 PM
Cinemag have done it. No need to try to reinvent the wheel - Purple and Cinemag have already sorted it out. Please see the last post on page one.

I've sent off the files and am having a small batch of boards made which I'll offer on the Black Market. Meanwhile I'm working on a PDF file and a page describing the project with top and bottom layers for home-etchers.
Title: 1176LN Rev D DIY
Post by: rascalseven on January 07, 2007, 03:48:20 PM
That's awesome!  If you decide to make a run of PCB's available, I'm in for 2 boards and 2 trannies.

:thumb:

JC
Title: 1176LN Rev D DIY
Post by: Orleanska on January 07, 2007, 03:51:18 PM
I'd be in for two transformers and two boards.

regards
Denis
Title: 1176LN Rev D DIY
Post by: radiance on January 07, 2007, 04:04:38 PM
I'm in for boards AND transformers..........
Title: 1176LN Rev D DIY
Post by: Whizard on January 07, 2007, 04:25:23 PM
I am definenytly in for two boards and two transformers!
Title: 1176LN Rev D DIY
Post by: flaheu on January 07, 2007, 05:03:13 PM
I'm in for 2 boards and 2 tranies  :grin:  :grin:

Keep us updated  :thumb:  :thumb:
Title: 1176LN Rev D DIY
Post by: HarryH on January 08, 2007, 05:43:14 PM
I think a group buy would be great,Im in for 2 boards.
Harry
Title: 1176LN Rev D DIY
Post by: BladeSG on January 08, 2007, 06:46:10 PM
Beautiful work there Mako  :thumb:

I don't know how I've missed this thread so far, but anyhow if boards are made available I'll be in for 1 board and 1 transformer too.

Steve
Title: 1176LN Rev D DIY
Post by: Sleeper on January 08, 2007, 10:42:51 PM
Quote
Cinemag have done it. No need to try to reinvent the wheel - Purple and Cinemag have already sorted it out. Please see the last post on page one

I see the altran numbers, but not a cinemag one, though edanderson says it's posted somewhere...  I'll have to have a look around.
FYI
If there is a group buy in play, I've been told that Altran will also probably do smallish runs(like 50)
It looks like everyone is thinking there is a group buy hapenning for the transformers, I'm not sure if this is really the case is it?


I'm in for 2boards and 2 transformers as well.
at least 2 boards from you mnats.
Thanks
Kelly

OK I looked, I see some cinemag numbers, but I really don't know
if I'm looking at the right one.  edanderson?
Title: 1176LN Rev D DIY
Post by: Prophonic on January 09, 2007, 06:03:47 AM
Hi Mako,

I would be also in for 2 boards and trannies if a group buy takes place.

cheers

prophonic
Title: 1176LN Rev D DIY
Post by: kazper on January 18, 2007, 04:10:51 AM
Me two for 2
Title: 1176LN Rev D DIY
Post by: enthalpystudios on January 18, 2007, 12:43:38 PM
VERY cool mako.


i don't know why one would want to build this circuit without feedback....  seems like a silly idea to me, or with lundahls or especially oeps, seems thats what the g1176 is all about.

the altran is the same pinout as jensen/cinemag, and i believe even has it listed on their page.  this is an O-12 clone.  i can measure one if you'd like....  the cool thing, however, is that the pads could probably be multi transformer, fitting different types.... any 500:200 or probably even 600:150 or thereabouts would work well enough.  if they could do it, and if someone has the specs, edcor would be a perfect candidate, imho, to do a custom job on the output transformer.  I think altran would also do lit at a could group buy price but i don't know for sure.  they'll do the lo1166 at a 25+ price.

edcor is sweet cuz they'll do a one off custom tranny.  but hey, maybe if worst comes to worst a brave soul needs to send an o/p trafo to The CJ to reverse specs

hopefully not.  if it meant a trafo that could be used in 1176 class A (*and* an 1108 micpre) at a decent price, i'd certainly sacrifice
Title: re 1176
Post by: safe as milk on January 18, 2007, 04:01:08 PM
hi

i've got a couple of old rev d 1176's,
both will be getting a bit of a service over the next couple of weeks,
if you need a trafo sent to cj, i can live without one of
the units for a while.

input/output  or both, whatever for the greater good.

cheers

justin
Title: 1176LN Rev D DIY
Post by: edanderson on January 19, 2007, 12:48:33 AM
i don't want to stop anyone from doing anything they want to do (feed teh CJ monstah at yer own peril!), but i already have the complete winding info for the 1176 OPT, and i am working to have them available for anyone who wants one at a reasonable price.  the cinemag part number can be found in a previous post.

of course i can also supply the O-12 repro input transformer that purple uses.  as billy mentioned, the pinout is the same as the cinemag/jensen types, so most of the usual 1:1 ratio line inputs can be used with minimal changes.

please do not PM me about transformers; i will be making a post about the transformers i have for sale in the black market.  you can also email me at edanders at gmail.com

ed
Title: 1176LN Rev D DIY
Post by: guavatone on January 19, 2007, 02:44:13 AM
I totaly missed this.  I may be in for 2.  I can't seem to recal the revisions but I thought F was the more "desireable."
Title: 1176LN Rev D DIY
Post by: mnats on January 19, 2007, 06:01:24 AM
Quote from: "guavatone"
I can't seem to recal the revisions but I thought F was the more "desireable."

If that is your preference you should probably go with a G1176.

Nice offers to sacrifice iron to CJ or Edcor but if Ed is on board for a group buy of the Cinemag output and Altran input it's probably not necessary. I would love it though if someone could send their iron to me for a few weeks to test with my layout.

As I mentioned in my second post on the page 2 of this thread, I have left the transformers off-board both for ease of experimentation and for added durability of the finished unit. It may also help solve problems not to be locked into fixed placements when trying to reduce hum from the power transformer...

I just received word that the boards have shipped so I should see them in a week or so. They will be offered on the Black Market as soon as they arrive. Still working on documentation and a home-etch layout so maybe everything will come together at once.
Title: re 1176
Post by: safe as milk on January 19, 2007, 06:34:59 AM
hi

i did'nt realise all the trafo info was already sorted,
i'm more than happy to go with cinemag etc

i can lend you some iron if you want but it wont be for
a couple of weeks?

could you please put me down for 3 board sets.

thanks to mnats and ed anderson
Title: 1176LN Rev D DIY
Post by: enthalpystudios on January 19, 2007, 03:04:50 PM
so awesome....  also, not sure if you'd consider it, but an altran or cinemag input would probably actually be best onboard, just because its pc mount in the first place...  or perhaps someone knows of a chassis mount collar that fits these size/shape transformers.

but yeah, the output *definitely* belongs off board, its heavy.  and etc.
Title: 1176LN Rev D DIY
Post by: mnats on January 22, 2007, 06:31:45 AM
Some documentation including self-etch files can be found on my site (http://geocities.com/m_natsume/1176_revision_d.html).
I've also received a batch of boards and have them on offer in the Black Market (http://www.groupdiy.com/index.php?topic=240374). I'll re-post this information at the start of this thread.
Title: 1176LN Rev D DIY
Post by: radiance on January 22, 2007, 07:00:15 AM
And again a very nice web page/ tutorial site you've made!
Title: 1176LN Rev D DIY
Post by: tomcat on January 22, 2007, 04:11:25 PM
Another cool mnat project :)

Do you plan just to make this pacth of boards and when its gone its gone or will they also avail. later?
Title: 1176LN Rev D DIY
Post by: Phrazemaster on January 22, 2007, 09:05:48 PM
Pretty dang amazing work!! Such detail, and so clear! Ok I'm drooling, and I haven't even finished my first diy green pre lol.

Thanks mnat!  :green:  :thumb:
Title: 1176LN Rev D DIY
Post by: tomcat on January 23, 2007, 06:49:36 AM
Ok, couldnt resist and ordered the boards already ;)

Btw. i have problems sourcing the 2n3707. Anybody have a source for it, preferably in europe?

Btw. any matching required? Or just the same like the rev. F 1176?
Title: 1176LN Rev D DIY
Post by: mnats on January 23, 2007, 06:50:55 AM
Missed a few things in the thread that I'll try to clear up.
Quote from: "mkoz"
May I also ask your help once my brother and I get this flexi-76 challenge working too?
Sorry, but I don't quite understand what you're asking...

Quote from: "tomcat"
Do you plan just to make this pacth of boards and when its gone its gone or will they also avail. later?

Dunno. Suppose it will depend on whether there is further interest in them or if it just fizzles out.

Quote from: "matthias"
for the meter circuit I would go for a classic meter buffer as purple did that in their mc77

Your options are totally open. But the PCBs themselves contain just the original circuit with nothing added or taken away.

Quote from: "safe as milk"
what are you going to use for input iron?

If Ed offers the O-12-like transformers I'll try those. For the prototype I just used an OEP A262A2E wired 2:1.

The Rev D page (http://geocities.com/m_natsume/1176_revision_d.html) is a work in progress. Suggestions and corrections are welcome. It's going to be interesting to see the comments once folks start building their Rev Ds. Can't wait!
Title: 1176LN Rev D DIY
Post by: Lowfreq on January 23, 2007, 03:07:18 PM
Mako, your pages are fantastic!! So well written and layed out, that even an electronics retard like myself made two 1176's that worked first time!!
the Rev D page looks great too. :thumb:
Title: any boards left ?
Post by: pacemaker on January 24, 2007, 04:25:39 PM
hi Mnats,
is there any boards left ?
I'm interested in 2 boards,
Regards to everybody,
Pacemaker
Title: Re: any boards left ?
Post by: mnats on January 25, 2007, 03:13:45 PM
Quote from: "pacemaker"
is there any boards left ?

Please check the Black Market thread 1st post (http://www.groupdiy.com/index.php?topic=240374) for information about the batch of boards I've made for this project.

Could we keep this Lab thread for discussion of the Rev D project itself please?

Quote from: "tomcat"
Btw. i have problems sourcing the 2n3707. Anybody have a source for it, preferably in europe?

Btw. any matching required? Or just the same like the rev. F 1176?

I bought my transistors from Mouser. They ship internationally at fairly reasonable rates. Use their USPS Global Priority Mail option.

For matching suggestions, check my Revision D page (http://geocities.com/m_natsume/1176_revision_d.html) linked a few times so far or download a copy of the manual + schematics (should be still up on the JBL website) to read it from the source.
Title: xformers !!
Post by: pacemaker on January 26, 2007, 05:34:04 AM
i'm also interested in the xformers group buy,

would be very nice to get the real Irons !!

Mnats, what resistors will you use for this projetcs,
Carbon ?
Title: 1176LN Rev D DIY
Post by: tomcat on January 26, 2007, 05:41:57 AM
Is there any matching for the transistors required?
Title: 1176LN Rev D DIY
Post by: gevermil on January 26, 2007, 10:00:11 AM
also interested in the xformers group buy
Title: fixed parts list v1
Post by: kato on January 26, 2007, 02:48:22 PM
I made a parts list with links to the parts at digikey/mouser → here (http://nimbleswitch.com/diy/1176_revD_parts.html)

[edit]switched from PDF to html because making new pdfs with each new edit is a pain.  if you downloaded the pdf, the version above incorporates mnats revisions below...[/edit]

not verified. i can't promise that this is complete or accurate  - but I will do my best to update it as errors are found.

If anyone would like to suggest better or more appropriate parts for certain values, please do.
Title: 1176LN Rev D DIY
Post by: zul_nalury on January 27, 2007, 01:29:48 PM
Nice job Kato...
Title: 1176LN Rev D DIY
Post by: mnats on January 27, 2007, 05:12:14 PM
Good work on that parts list. You made some premium choices there: multiturn trimmers, polyprop film caps...

Unfortunately, I made an of error on my parts list. There should be one more 2k trimmer, R44 and one less 1k resistor of the same designation (it was a late revision to the board). Also, I would suggest that C23 not be a tantalum as it sits right across the 30V rail (reasons have been raised here (http://www.groupdiy.com/index.php?topic=19810)). An electrolytic rounded up to the nearest common value would probably be better there.

Thanks for your efforts! Is it OK to add a link from the 1st post and maybe to link from my Rev D page?

Oh sh*t, one other thing. The output transistor should have a heat sink attached. I'm going to give this one (http://www.mouser.com/search/ProductDetail.aspx?R=578305B00000Gvirtualkey53210000virtualkey532-578305B00) a try...

Since someone keeps raising the matching question does anyone have an idea why the schematic suggests matching Q5, the small signal transistor and Q6, the medium power output transistor (circuit posted on page 2 of this thread)?
Title: 1176LN Rev D DIY
Post by: kato on January 27, 2007, 07:32:24 PM
Thanks Mnats - feel free to link to it - or download and host it yourself - although I will leave it there indefinitely.

Quote from: "mnats"
Good work on that parts list. You made some premium choices there: multiturn trimmers, polyprop film caps...


That might be a newbie maneuver. Since I don't know which portions of the circuit are critical - I throw quality parts in every corner. Let me know if there are less critical components where a cheaper part should be specified.
Title: 1176LN Rev D DIY
Post by: JdJ on January 29, 2007, 11:03:30 AM
Just wanted to say thanks to Kato and Mako-  you guys make this stuff too easy!  Nice job on the BOM!

BTW is everyone else seeing scrambled avatars?

Cheers
 :guinness:  :guinness:  :guinness:

Josh
Title: 1176LN Rev D DIY
Post by: kazper on January 29, 2007, 09:02:53 PM
Was the UTC 0-12 input transformer sort of able to be replaced with the cinimag cmmi-2c in backwards....?
Title: 1176LN Rev D DIY
Post by: Bri on January 31, 2007, 10:47:14 PM
Kato- In your BOM, a few of the resistor part numbers "271-2.7M-RC," "271-10M-RC," and "271-1.2M-RC," for example, show as "no results found" on Mouser's site.  Did you mean, for example, "291-2.7M-RC"....1/4watt carbon film resistor(5% tolerance)?

I'm not complaining in any way...I appreciated your parts list very much.  I just wanted to be sure.

Also, does anyone have a source for the 600ohm "T" Attenuator?
Perhaps added to the up-and-coming(hopefully) xformer group buy?

--Brian
 :guinness:
Title: 1176LN Rev D DIY
Post by: Lowfreq on January 31, 2007, 11:26:51 PM
Quote from: "kato"
I throw quality parts in every corner. Let me know if there are less critical components where a cheaper part should be specified.

I was wondering that too. I orded wimas for all the poly's in my last 1176, but from the pics of Mako's rev D board, I only see 2 wimas, and the rest look like the poly's from jaycar or dick smith.(southern hemisphere DIYers will understand)

I'll have a closer look at the schem, just to educate myself a little better.
I'm slowly getting better at understanding them. :oops:

A little off topic. A well known (well in NZ) engineer/producer borrowed my Mnats G1176(lundahl loaded) to use in a session. Kinda daunting for a bedroom studio engineer seeing it alongside a bunch of real 1176's in a real studio :shock: , but his resonses were "Nice work" and "I like it!!"

I told him I was looking at the rev D version, and He's really keen to hear that too, once it's built.

Righto, as you were
Title: 1176LN Rev D DIY
Post by: jho-audio on February 03, 2007, 03:44:33 PM
Will the DC gapped JLM 1:1:1 output transformer work in place of the UA5002?  http://www.jlmaudio.com/JLM111DC_Output_Transformer.htm
Title: 1176LN Rev D DIY
Post by: mnats on February 03, 2007, 06:51:34 PM
Quote from: "jho-audio"
Will the DC gapped JLM 1:1:1 output transformer work in place of the UA5002?  http://www.jlmaudio.com/JLM111DC_Output_Transformer.htm

Check this post (http://www.groupdiy.com/index.php?topic=235027#235027). Though I think Ed should be along with the right transformer soon.

BTW, kato - I did mean C23 shouldn't be tant, not C19 and C20 too as these don't sit across the 30V rail and low leakage are specified here. Even though I've been told most modern electros are much lower leakage the leakage current is still higher than a typical tantalum. I should probably separate them on my own parts list...
Title: 1176LN Rev D DIY
Post by: thenovice on February 03, 2007, 08:27:28 PM
Quote from: "edanderson"
Quote from: "Rob Flinn"
Greg

That looks really good !   Nice & compact.

One thing.  I'm wondering why you didn't take the opportunity to use 25 turn trimmers, which make the 1176 much easier to set up?


i second this idea.  multiturn trimmers make a big difference; hopefully your new layout can accept a few kinds of trimpots.  i would also change the selected (usually around 1k) GR meter calibration resistor to a 2kohm trimmer in series with a 100ohm resistor.  this makes the GR meter calibration easier.

i don't suppose there is room for the pcb mount input transformer?

board looks very nice, btw.

everyone should realize that for max performance you'll need the specialized output transformer.  a simple gapped 1:1 could probably substitute acceptably.  purple will not be selling the output transformers after the new year, but i've posted the cinemag part number before.  if there is enough interest, perhaps i can arrange some kind of group order.

ed


those were PN:

cinemag pa96731
&
cm96731-A

correct?
Title: 1176LN Rev D DIY
Post by: kato on February 03, 2007, 09:27:06 PM
Quote from: "Bri"
Kato- In your BOM, a few of the resistor part numbers "271-2.7M-RC," "271-10M-RC," and "271-1.2M-RC," for example, show as "no results found" on Mouser's site.  Did you mean, for example, "291-2.7M-RC"....1/4watt carbon film resistor(5% tolerance)?


Thanks Brian! I didn't click every link. I created them by search-and-replace so thanks for the heads up!

Quote from: "mnats"

BTW, kato - I did mean C23 shouldn't be tant, not C19 and C20 too as these don't sit across the 30V rail and low leakage are specified here. Even though I've been told most modern electros are much lower leakage the leakage current is still higher than a typical tantalum. I should probably separate them on my own parts list...


Thanks Mako - C23 is electro, C19 and C20 are tant - got it.

Parts list updated to reflect above two changes. Keep 'em coming. I'll continue updating as needed.

Tantalums currently specified have ESR value of 2.5 Ohms and voltage rating of 35v. Kermet brand, 67¢ ea. Is lower ESR required/preferred? Let me know; I know not dick about tantalums. These are cheaper than the previously specified AVX brand which were twice the price.
Title: 1176LN Rev D DIY
Post by: ChrioN on February 05, 2007, 06:52:58 AM
Boards recieved and they look stunning. The layout is exellent, nice modular feel to it with all the different parts squared in.
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 05, 2007, 03:39:21 PM
Please don't shout at me if I am missing the bleedin' obvious . . .

   can anyone please be so kind as to point me to the circuit diagram for this particular version?

  and, yes, I have searched and searched - can;t actually read the version i have found, which is incomplete anyway(cut off on the rhs)


   many thanks!


             ANdyP
Title: 1176LN Rev D DIY
Post by: Bri on February 05, 2007, 04:29:42 PM
Ignore me if you know this already. :)

Mnats has a link to his "Revision D" information in the first post of this thread:
 "Some documentation including self-etch files can be found on my site."

That link takes you to his "Building The DIY 1176LN Revision D page."
On the top left of the page is:"Revision D PDF File (includes self-etch files and bill of materials)"
Clicking on this opens the PDF file containing the schematic.  

Here's a link to it. (http://geocities.com/m_natsume/files/MNATS1176REVD.pdf)

The circuit diagram is on page 5.

This is the only one I'm aware of.  Hopefully it's not the one you're having trouble with.

Cheers.

--Brian
Title: 1176LN Rev D DIY
Post by: mnats on February 07, 2007, 06:07:49 AM
Pretty sure the big 1176 document is still posted at the JBL Professional site. Also, the Purple site should have a schematic for their version on their PDF. But yeah, the PDF linked from my Rev D page is the actual schemo used to lay out my boards. It is missing the input circuit because there are so many choices you could make and none of them are included on the board.
Quote
Parts list updated to reflect above two changes. Keep 'em coming. I'll continue updating as needed.

I would go for the YB version of the Vishay/Sfernice trimmers, because the offset pin will give a little more mechanical stability.

But it brings up something that I have been thinking about for a while. Not that I'm ungrateful, but I never really liked parts lists like this, because part of the fun of DIY is choosing which parts you want to use in your project.
Title: 1176LN Rev D DIY
Post by: kato on February 07, 2007, 07:03:34 AM
Quote from: "mnats"

I would go for the YB version of the Vishay/Sfernice trimmers, because the offset pin will give a little more mechanical stability.

But it brings up something that I have been thinking about for a while. Not that I'm ungrateful, but I never really liked parts lists like this, because part of the fun of DIY is choosing which parts you want to use in your project.


I agree completely. I made the list for myself. And thought it might be useful for a few others. But I never wanted it to be considered any kind of officially sanctioned by mnats parts list. You may consider removing your link to it in the first post to avoid that appearance.

I am still quite new at diy. My first 1176 channel was built using Greg's parts list and as a newbie I found it incredibly helpful; I had no confidence facing a 1700 pg mouser catalog - I didn't know where to begin. My own parts list is suspiciously reminiscent of his in that I use the same panasonic/epcos ceramics. They served me well and I now rely on that epcos page in the mouser catalog as if a friend personally recommended them.

Your suggestion of the YB series trimmers is also helpful. I will try them for myself. Again, a friend (you) recommended them and I may learn something from that suggestion.

I want to hear suggestions about my parts list as a learning experience for myself and others. But not as a we unanimously agree on these parts lemming line. I expect the majority of builders to choose their own parts - and for the minority who want a convenient north american parts list, I hope it will serve as a starting point.

Thanks for bringing that up. And thanks again for sharing this project.

Kato
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 07, 2007, 01:04:23 PM
many thnaks for the links.

   All makes sense now. I do have a couple of 600r constant impedence attenuators, but was wondering if anyone has a source for more since I use them a lot for turning down cthe output of overdriven preamps Also, i cannnot establish what impedance/ratio the O-12 input transformer is. Will 600:600 do, or 600:150? I have some Gardners 600:300 . . .

   this is so cool, i LOVE the class A version SO much more than the later ones. Way to Go!

    All the best,


               ANdyP
Title: re 1176
Post by: safe as milk on February 07, 2007, 01:38:42 PM
hi

link for 0-12 info

http://vacuumbrain.com/docs/Sub_Docs/utc.html

cheers cj
Title: 1176LN Rev D DIY
Post by: flaheu on February 07, 2007, 02:15:22 PM
I'm more concerned by the input attenuator  :sad:
Mnats can you tell more about
Quote
B version of the Vishay/Sfernice trimmers

Is that a "special" assembled atten/pot stuff ?.

Available somewhere ?

Cheers
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 07, 2007, 02:56:36 PM
Thanks Safe as Milk/CJ!

   can i safely deduce that it is wired backwards from the diagram? ie 500:250? I do hope so, 'cos Ive got a spare pair of Gardners 600:300 he he he.

    Thanks guys,

       ANdyP
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 07, 2007, 03:19:38 PM
flaheu,#


  i think he is refering to the trimpots mounted on the pcb, not the input attenuator . . .

   please someone correct me if I'm wrong. . . .


          AndyP
Title: 1176LN Rev D DIY
Post by: Lowfreq on February 09, 2007, 05:55:08 PM
I've got one of those cinemag CMLI-15/15B input transformers sitting round here, which from what I can gather is what UA are using in their reissues.

But it's 15k:15k, And from what I've read (a few of W.O.B & Ed's posts) UA are not doing the T attenuator thing. Just using an input pot.

Even tho there have been a few discussions about using the tranno,I can't seem to find what pot I should use. The G1176 uses a 10K audio for the input. I'm thinking just doing the same and wiring the tranno 2:1.

Does anyone have specifics on how UA work around the CMLI-15/15B?
I can't justify spending money on more iron, and I'd prefer to use what I've got. Save the $$ for the correct output transformer.

I know it's not the authentic way of doing it, but I've still never used a real 1176, and this will be my third 1176 clone, :shock: so I'm not too fussed getting it exactly like a revD. Just close................ :roll:
Title: 1176LN Rev D DIY
Post by: enthalpystudios on February 09, 2007, 06:13:23 PM
the attenuator is most important......   thats really what we should iron out first.   but i'm not sure where to begin on something like that guy.

maybe we could use 24pos switches ;]


thats a lot of resistors though.  i dunno..  there's got to be a way to get them.

but for reference, this rev d. board is not really anything like the UA stuff.  this is basically the same circuit that used the utc o-12 input transformer.

it was 500z:200z.   600:150 or similar should be just fine.  the important thing is having a passive attenuator up front, before the input transformer.
Title: 1176LN Rev D DIY
Post by: Lowfreq on February 09, 2007, 07:06:38 PM
mmmmm, ok........... I think once again, I need to carry on doing some more reading.........and learning :wink:

So the UA claims of being based of rev d/e is quite a loose claim then?


This is some of what I found in some other threads.
Quote from: "Winston O'Boogie"

Family Hoof wrote:
[...and shunted the secondary with a pot (instead of placing a T-attenuator BEFORE the transformer. According to most users this doesn't sound as good, or even similar.


Not quite correct. I recall doing two versions of "new" front end for UA using that 1:1 Cinemag.

One version (1176LN) terminated the secondary with a fixed R and, on the primary, had a pair of series R's feeding a shunt pot, then a pair of smaller R's to feed the winding. The combination of the series R's and the pot (set for no attenuation) gave about a 4dB loss, same as the 0-12 was. The load on the source was not constant but was always fairly low. FWIW, the Cinemag seemed to be fine with the shifting input Z.
This might not sound the same as a 'T' atten and 0-12 but it is an alternative. Maybe not a good one if you're building a "clone"  but, IMHO, fine for DIYing etc.

The other version (6176) had a pot on the secondary with a series R feeding the top of the pot to attain the same 4dB drop and also terminate the transformer effectively. This arrangement presented a constant Hi-Z load to the source...

gyraf wrote:
- it will present a gentler load to the previous stage. Not all equipment sounds good when loaded that hard..
Jakob E.


And some stuff sounds better with a low load which is why, on the 6176, you could switch in the 620R primary loading resistor that I shoved on a switch on the back panel...  


But again, I'm still getting my head round trasnformers, attenuators etc, so I could be pissing into the wind..... :roll:
Title: 1176LN Rev D DIY
Post by: JdJ on February 09, 2007, 09:36:58 PM
Here's some interesting stuff on T Attenuators:

 Floating? (http://www.groupdiy.com/index.php?topic=138850&highlight=balanced++attenuator#138850)

 Why it's important  (http://www.groupdiy.com/index.php?topic=138850&highlight=balanced++attenuator#138850)

 More with a schem by NYD  (http://www.groupdiy.com/index.php?topic=2229&postdays=0&postorder=asc&highlight=balanced++attenuator&start=15)

Hopefully some of this is useful...

I'm still not sure how I'm going to pull it off.  Some threat around here had someone suggesting going to the source for UA with the requirements.  Group buy?

Cheers,

J
Title: 1176LN Rev D DIY
Post by: tommypiper on February 10, 2007, 12:00:48 AM
I'm wondering the same things about the T.  Making a DIY attenuator looks to be too much so far.  

Doubt if going to UA would yeild anything fruitful; shudder.

Maybe there is a way we could make a simple 3 position attenuator?  Hi, med, lo? With a few switches and resistors?  Just to have ballpark input sensitivities which would suffice in most cases?

How much attenuation (in dB) are we talking about?  I've seen old surplus Ts but have no idea what range we need.
Title: 1176LN Rev D DIY
Post by: JdJ on February 10, 2007, 10:05:14 AM
Ooops-

Meant to post this one-

 NYD's Bridged T Schem (http://www.groupdiy.com/index.php?topic=4825&postdays=0&postorder=asc&highlight=dual+1176&start=0)

 More T Talk (http://www.groupdiy.com/index.php?topic=10593&postdays=0&postorder=asc&highlight=1176+attenuator&start=0)

Sorry- I just wanted to have these all in one place...

-J
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 10, 2007, 10:47:47 AM
I have just downloaded the Purple MC77 documentation, and they seem to have used a simple 2-ganged pot(value not given, but I guess 500R) and 2 resistors befor the o-12 or equivalent transformer. LAter versions use a 3-deck pot, with 500r x 2 and 5k.

   Sorry, i am crap at posting links - they never work for me.

   Could someone help with a "loading" question? i actually have a pair of t-attenuators, and a pair of Gardners 600:300 transformers. Would I need to increase the value of R4(270R) if the transformer is 300R?

  Also, if I might be so presumptious, if i don't use the Cinemag or whatever equivalent, and ignore the feedback tap, what kind of transformer should it be? 150/150:600R?

  Many thanks,

 ANdyP

   Many thanks,

     ANdyP
Title: T confusion
Post by: tommypiper on February 10, 2007, 02:12:12 PM
Can anyone summarize the situation and provide specs, schems, info? Is everyone as confused on the Ts as me?

:guinness:



Edited for brevity.
Title: attenuators
Post by: edanderson on February 10, 2007, 02:40:24 PM
over the life of the products, the purple MC76 and MC77 used both the "original style" bridged T attenuators (two decks + two fixed resistors) and a non-bridged T attenuator (three decks).  these two devices are essentially electrically equivalent, in that when they are at full CW rotation, there is almost no attenuation, and at full CCW, there is more than 50db of attenuation.  at any position in the rotation the impedance is approximately 600ohms.

today there are two available choices, neither of which is cheap.  the three deck non-bridged T attenuator is made by state electronics for purple, using clarostat 70 series mod pots.  they feel smooth and should last forever, but they are not cheap.  i know at one point andrew was asking $70ea for them, and i'm not sure he'll be selling them at all any more.

PEC in canada makes a reasonable facsimile of the two deck bridged-T attenuator, and supplies them to UA.  i think i heard about someone getting one from UA for ~$50?  but then i believe the same person said it was scratchy after six months.  i got a quote from precisionsales.com and the 50 pcs price was $35ea.  the part number is 05-0007 if anyone wants to go that route.  you are unlikely to find anyone else willing to make the unusual tapers that are required for this part.

ed
Title: 1176LN Rev D DIY
Post by: JdJ on February 10, 2007, 02:48:17 PM
Perhaps we can start here: (http://www.groupdiy.com/index.php?topic=10593&postdays=0&postorder=asc&highlight=1176+attenuator&start=15)

Quote from: "edanderson"
Quote from: "EP"
You will need 2- 500 ohms, and 1- 1k ohm.
Configuration 500-1000-500 ohm


for a 500 ohm (close enuff to 600) config, the 1k will have to be a log/audio or what clarostat calls "Z" taper.  otherwise the impedance and level change will not be how you want.  also, a 1/2w rated pot could theoretically be burnt out by driving ridiculously large signals into it......

ed


Quote from: "edanderson"
it is a custom 70 series clarostat 3 deck pot with a two 500 ohm decks and one 1kZ deck.  they aren't cheap, and we do have to wait for them to be made to order.  we've had more problems with getting the meter and ratio switches than any other part.

ed


Sorry for all the confusing links- I just figured it was best to have a few sets of eyes on this stuff as I am not as good at figuring out details as many... :oops:

Sounds like getting Ed in here would be helpful.

BTW the MC77 Schematic is here (http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf) on page 14.  It shows both the old 2 deck and newer 3 deck jobbies.
:guinness:

-Josh

EDIT: dang! his ears must have been burning!!  snuck in under the wire...
Title: a stab at the UA input idea
Post by: edanderson on February 10, 2007, 03:17:51 PM
(http://edanders.home.comcast.net/diy/UA76in.gif)

from john's ("winston") post, i would guess that he was talking about basically an H-pad with a pot acting as a variable shunt, as sketched above.  this, together with a 1:1 transformer is a valid way of doing a pot as attenuator into the transformer.  it is not the same as what was originally done, and wouldn't necessarily sound the same (though it could in some cases).  the big advantage of this approach is that the parts cost would be lower and the parts much easier to get.

ed
Title: input transformer loading
Post by: edanderson on February 10, 2007, 03:21:47 PM
in the case of using a non original input transformer (anything other than an O-12 or the equivalent), the termination resistor across the secondary would have to change.  the "correct" value is dependent on the characteristics of the transformer itself, and the way the attenuator is done.

pretty much the best advice i can give is to wire up whatever you have and see what you get.  then tweak to taste.

ed
Title: 1176LN Rev D DIY
Post by: JdJ on February 10, 2007, 03:25:59 PM
Thanks Ed!

It's always a pleasure to get this stuff from the source...  And a viable alternative to the T!

:guinness:  :guinness: :guinness:

-Josh
Title: Re: T confusion
Post by: tomcat on February 10, 2007, 03:43:41 PM
Quote from: "tommypiper"
I think we need to establish a starting point, a knowledge base and facts, before we can all safely start figuring out (so many different) solutions.


Would love to see that :)

Im completely lost when its going to things like T-Attens., In- and Output Impedances and so on....
Title: non-original output transformer
Post by: edanderson on February 10, 2007, 03:44:03 PM
the output circuit of the rev D/E 1176 is specifically designed to work with the original output transformer.  if you don't intend to get the original transformer, and you want something like an 1176, i would suggest not building the rev D/E version at all and building a rev F style G1176 instead.

if, however, you are interested in getting something going that may behave rather differently than the original circuit, i would say to start with a gapped, M6 steel core, 1:1 600ohm output transformer.  

the JLM111DC might work, but will cost the same as the original part, and not have the additional windings.  a LO1166 type *might* work in a 200:150 configuration, but i wouldn't expect stellar performance.  i can't think of anything in the standard range from sowter, but i'm sure they could make a simple gapped 1:1 on request.  i would guess that lundahl could adapt one of their tube interstage transformers to roughly fit, but it would be quite expensive.

when the cinemag outputs are ready, i will put up an ad in the black market.  it should be towards the end of this month.  if i come up with a less costly solution that would work for budget DIYers, i will post that also.

ed
Title: 1176LN Rev D DIY
Post by: tomcat on February 10, 2007, 03:57:16 PM
Thanks for the info. Im waiting already for the cinemags since i read some post about it some time ago. So far the output is solved.

The big  :?: for me is still  ... what to do with the input? Some sort of 1176D input for dummies info... :wink:
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 10, 2007, 04:51:35 PM
Ed,

   

   :oops:  :oops:  :oops:  i had no idea I was so near to the "source" . . . Thank you so much for all your invaluable advice. It is surely greatly apreciated.

   just one thing, i am not able to see how a 600:600 output tranny  would work, since there appear to be 2 seperate windings on the primary? Do you meen 150/150:600, or am I missing something here? I would be very interested in any group buy for da real deal . . .

  I am not a "clone purist". I merely like great sounding gear. Slight diffferences are to be encoursaged in my book. i have lots of "unique" lash-ups in the studio! Right now, I am considering a 2520 driving a 10klog pot for the input . . . .


    All th ebest.,

     ANdyP
Title: 1176LN Rev D DIY
Post by: mnats on February 10, 2007, 06:47:43 PM
Quote
just one thing, i am not able to see how a 600:600 output tranny would work, since there appear to be 2 seperate windings on the primary?

I think Ed was referring to alternatives to the correct part, so these alternatives would not have the same features as the original or the copies he's going to offer.

The second "primary" I think that you are referring to is a winding that takes the V+ current "backwards", offsetting the voltage produced by the output of the class A amplifier stage (if my analysis is correct). If you fed that 30V into two equivalent primaries like the 150/150 you gave as an example, you would be overcompensating for the small voltage at the output.

A gapped transformer doesn't care if there is a small amount of DC at the output. So you would just forget about the other winding and feed the 30V directly into the line output stage (shorting together brown and black as shown on my and the Purple document).

For the input it seems to me the answer is clear: if you want something like the original find a 600 ohm T attenuator and a UTC O-12. It might take a little time and effort, but like I've said earlier this ain't a G1176.

If you want have some fun and try something new, try some of the things that have already been suggested. You could even feed an unbalanced signal through a pot and into the board directly.
Title: 1176LN Rev D DIY
Post by: edanderson on February 10, 2007, 08:39:37 PM
edit: mako's analysis is correct, but it is more complicated than it seems.

ed
Title: RE: a stab at the UA input idea
Post by: Lowfreq on February 10, 2007, 08:51:42 PM
Cool, thanks Ed. :thumb:

Ideally I'd like to have the correct transformer and a T attenuator, but for now I'll just work with what I've got.

Thanks for the info
Title: 1176LN Rev D DIY
Post by: tommypiper on February 10, 2007, 09:00:57 PM
Thanks Ed, Mako and everyone.  Great discussion, interesting project.

I'm looking at this.  It seems fairly straight forward.  (Thanks NYDave)

Quote from: "JdJ"
NYD's Bridged T Schem (http://www.groupdiy.com/index.php?topic=4825&postdays=0&postorder=asc&highlight=dual+1176&start=0)


Also, seems like the PECs might be available according to Ed's earlier post today.   Perhaps in less than 50 pieces too.

Then there's experimenting.  I mean, why would you need to have 600 ohm on the inputs today anyway?
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 10, 2007, 11:34:05 PM
Guys,

  Thank you all for your replies, but perhaps I am not expressing myself properly. on the rev D diagram, there are more ""coils" than can be derived from a 600:600. So which do i ignore? brn to blk, whtblk to whtred, or grey to violet?. surly only one pair is valid. since x to y is the output?


      I do hope I am not missing the wood for the trees.


    All the best,


      AndyP
Title: 1176LN Rev D DIY
Post by: mnats on February 11, 2007, 12:00:08 AM
Quote from: "strangeandbouncy"
on the rev D diagram, there are more ""coils" than can be derived from a 600:600. So which do i ignore?

Since you're a fan of the Rev D, you won't ignore any of the windings and will just get the correct iron just hook it up as shown. But if you were to use a 'normal' transformer, you would short the black to brown terminals as described earlier (or you won't have any power going to the line output stage), connect your primary to white/black and white/red, then use your secondary as normal. Since you wouldn't have a feedback winding, the grey and violet pads would not connect to anything.
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 11, 2007, 12:03:18 AM
Mnats,

   thank you. I was just wanting to lash up the output until the correct output tranny is available.


   Many thanks,

 
       AndyP
Title: 1176LN Rev D DIY
Post by: tommypiper on February 11, 2007, 12:30:41 PM
What was the original input transformer ratio used 1.5:1?

cheers.
Title: 1176LN Rev D DIY
Post by: dissonantstring on February 11, 2007, 12:57:17 PM
hi tommy,
the original used a UTC 0-12 ouncer in reverse on input.
-grant
Title: 1176LN Rev D DIY
Post by: gevermil on February 11, 2007, 01:14:58 PM
500:200 ohms
Title: 1176LN Rev D DIY
Post by: tommypiper on February 11, 2007, 02:41:53 PM
Where do we find a UTC 0-12 diagram?  

cheers
Title: 1176LN Rev D DIY
Post by: Sleeper on February 11, 2007, 02:59:04 PM
First, MAKO, the boards are great, got mine nearly stuffed, and thanks for the psu boards!!  I'll run some relays etc. off of those. cool.

I've been looking over all the provided links regardingthe attenuator and i have a few questions still...

OK, so the dual pot approach is complicated because of the special Z taper (rev. log going in 2 directions) required. AND Ed Anderson says a 1/2 watt pot might get burned by high level signals.

Can a dual 1k be modified as below to get the taper... or will this raise havoc with our actual input and output impedences... I've used this a few times to change the law of a pot and it worked pretty well in simple unbalanced gain controls, not sure if floating this will cause problems.  
(http://www.twin-x.com/groupdiy/albums/userpics/normal_potsLOGtoLIN1~0.gif)(http://www.twin-x.com/groupdiy/albums/userpics/normal_potsLOGtoLIN2~0.gif)
more info. here
http://www.elby-designs.com/documents/tailoringpotentionometers.pdf

NewYorkDave's bridged-t looks pretty good.  It's not continuously variable, but my input sources mostly have some output control, enough to do the fine tuning.  
BUT?  I know pots are more easily toasted, but if a 1/2 watt pot might get burned, how come there are 1/4 watt resistors in the (purple diagram) t-attenuator? Can I use 1/4 watt resistors in the stepped bridged-t?

Thanks
Kelly
Title: 1176LN Rev D DIY
Post by: Sleeper on February 11, 2007, 04:54:14 PM
For the short term, problem solved...look at this clarostat CIBT43-600, Bridged T-Pad Potentiometer.
Kelly





 Looks like they have about 25 more of these - 29.95 each
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=013&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=230002096428&rd=1&rd=1
Title: 1176LN Rev D DIY
Post by: dissonantstring on February 12, 2007, 01:17:52 PM
Quote from: "tommypiper"
Where do we find a UTC 0-12 diagram?

here:
http://www.waltzingbear.com/Schematics/UTC.html
found this on uncle CJ's meta pages.  2nd page of pdf. file.
check page 4 of the pinout diagrams and look for diagram AG.
regards,
grant

man, i haven't checked the transformer meta pages in a while...uncle CJ has been busy!  everyone should check it out! :thumb:   great job CJ!! :guinness:
Title: 1176LN Rev D DIY
Post by: tommypiper on February 12, 2007, 02:07:00 PM
Thanks for the UTC link.  I'll have to check out CJ's activities.

Thanks to Sleeper for the heads up on the bridged Ts on ebay.  Looks exactly like the two deck on the Purple schematic.  Is it really the right one?  They're going fast.
Title: 1176LN Rev D DIY
Post by: kazper on February 12, 2007, 02:43:31 PM
I snatched up all I could afford at the moment (1) and there was 14 left
Payed for it refilled the coffee cup and came back to the forum and went to look again and now looks like 6 units left..
Title: 1176LN Rev D DIY
Post by: kato on February 12, 2007, 07:32:32 PM
And when 6 became 5:

Quote from: "ebay"
The seller ended this listing early because the item is no longer available for sale.
Title: 1176LN Rev D DIY
Post by: tomcat on February 12, 2007, 10:07:53 PM
Strange. There was 1 more available. Was... ;)
Title: 1176LN Rev D DIY
Post by: Sleeper on February 12, 2007, 11:36:37 PM
Wow guys, those went quick.
I should-a bought them all and sold them to you all at a profit.
Kidding-wink:
I have one of the clarostat datasheets and schematic wise the cibt is exactly the same as the PurpleAudio dual pot bridged -t. I hope they work as well it appears they should.  

One word of caution, I got a box once with a bunch of the clarostat attenuators- many different part numbers, l-pads, ladder attenuators etc.
they are most likely about 1 1/2 inches round, this could cause you trouble on stereo 1176 panel layouts.    

I'm still curious if the solution I posted above might work.  Like I said, I've used a resistor to change a potentiometers law before, but I don't have a scope that lets me make a graph or sweep and really see what happens if it is done that way.  I've changed linears to audio taper this way and they feel much better and sound ok.  I'm curious if pots modified this way would track ok.

Kelly
Title: 1176LN Rev D DIY
Post by: tommypiper on February 13, 2007, 03:25:44 PM
The Clarostats sale  is still active.  5 left.
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 13, 2007, 05:41:14 PM
Mnats,


   my boards arrrived this morning. Wonderful, and SO fast!



    BUT :shock:  :sad:  :cry:


    There appears to be a mistake or fault. I was stuffing my first board and checking as `i went, and found a dead short across R37(470k). The un-populated board is exactly the same, which by my reckoning. means that the input to the control amp is shorted. Plase forgive me if I am wrong, but . . . .

       Has anyone actually completed one yet?


      Help!


       ANDyP
Title: 1176LN Rev D DIY
Post by: kato on February 13, 2007, 07:45:58 PM
[edit]utterly useless post removed[/edit]
Title: 1176LN Rev D DIY
Post by: Sleeper on February 13, 2007, 08:26:00 PM
I've only partly stuffed my boards.  I took a quick continuity test, I have the same fault on r37 and also on another nearby resistor nearby (r36??? I don't remember the phone rang)...

You say it was this way before you populated the board... maybe there's a short to the groundplane.  Can someone check a board that hasn't received any heat?

I'm going to have to wait until I the rest of my parts arrive to do any more work on this, but I suspect, if there is a trace shorted to the groundplane we might have to lift a leg on r37 and fly it out to its proper destination... I hope that's all.

Kelly
Title: 1176LN Rev D DIY
Post by: kazper on February 14, 2007, 01:00:29 AM
from the schematic it shows that one side of the R37/470K goes to the O/ Electrical ground point also the center tap of the T3 transformer. You can see it connect to the ground plane on the top of the board from a + connecting it at 4 places on the hole close to trim pot. R41,R50,C21 also do this.

I'm no expert at, but it's always a good idea to put stuff together in sections and then test if you can.
Title: 1176LN Rev D DIY
Post by: mnats on February 14, 2007, 01:40:31 AM
I've just arrived home from work to find these posts and immediately took a look at my PCB file. My deepest apologies to everyone who purchased my boards.

When I built the prototype, I found that the originally specified 2N3707 transistors never met the 250 hFE spec. Because these 'trailing edge' devices have a different pinout than newer transistors, I added a base pad to make it easier to stuff a 2N5088 (the transistor Purple uses) in the control amp. As it was a last minute decision I unfortunately neglected to notice that I had not created a space on the ground plane for the additional pads.

Since then I have purchased a batch of 2N3708 transistors and each and every one of these meets the specification needed for this part of the circuit.

I have my own board 90% stuffed but am still awaiting transformers from Purple, so I have not had a chance to test them yet. But the fix shouldn't be too difficult - if you use 2N3708 transistors or have 2N3707s that meet the 250 hFE spec, simply cut the track for the additional Base pads on the bottom side of the board. If you are going with the 2N5088 I'm afraid the fix is a little more difficult as you will have to carve around half the pad on the top side to separate it from the ground plane.

Again, my sincere apologies for this oversight. If anyone would like a refund on their purchase I would be happy to comply.

I'll post pictures of the tracks that need to be cut as soon as possible.
Title: 1176LN Rev D DIY
Post by: Sleeper on February 14, 2007, 01:57:06 AM
Hi Mnats, thanks for the reply.

I'm not sure I knew about the marginal spec on the 2n3707s
maybe this should be changed on the bom?

yeah, I think a little photo of the track cut would be very helpful.

glad it's something easy.

Kelly
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 14, 2007, 03:50:23 AM
Mnats,

   does this track cut fix the shorted resistor or another one?

  ANdyP
Title: 1176LN Rev D DIY
Post by: mnats on February 14, 2007, 06:04:52 AM
I've edited this post after calming down and figuring out the obvious and easiest way to fix my prefabricated boards.

The top plated-through pads really do nothing on most of the components, save for the ones that attach to the ground plane. The error as discovered above is that an extra pad I added to the board in four places is attached to the ground plane rather than isolated from it.

(http://mnats.net/images/1176_rev_d_pcb_base_drill.jpg)
Solution: remove the top pad. Method: use a normal twist drill and gently remove the offending pads as pictured above. You can just twist the drill between your fingers. The copper pads are fairly soft and should come off after just a few turns.

You can still use this hole to mount the 2N5088 substitution after modification and, of course, the board will now work properly with a 2N3707/8 in the main footprint as well.

Archived, more complicated solutions below. See the images to identify the pads that need to be modified:

Quote from: mnats
Here are two possible ways to solve the problem of my stupid mistake. The first one involves cutting the tracks on the back (non-silkscreen) side of the board. Do this if you are going to use the 2N3707/8 footprints.

The second solution will work for either the 2N3707/8 or the 2N5088 footprints and involves cutting around the offending pads themselves on the top (silkscreen) side. The 2N5088 uses the extra transistor Base pad that has caused all the misery ;^(

(http://mnats.net/images/1176_rev_d_pcb_partial_stuff_lab.jpg) (http://geocities.com/m_natsume/images/1176_rev_d_pcb_partial_stuff.jpg)
Here is the partially stuffed board. You can click on most of these pics to enlarge them.

(http://mnats.net/images/1176_rev_d_pcb_gr_control_cu_lab.jpg) (http://geocities.com/m_natsume/images/1176_rev_d_pcb_gr_control_cu.jpg)
This is the section we are going to work on - the Gain Reduction Control Amplifier. Note that Q7 through Q10 have a single round pad near the oval ones. This is the Base pad that you would use if you are going to put a 2N5088 transistor or similar into the GR Control Amp. Otherwise for the 2N3707/8 you would just use the pads I have used in the example.

(http://mnats.net/images/1176_rev_d_pcb_base_cut_lab.jpg) (http://geocities.com/m_natsume/images/1176_rev_d_pcb_base_cut.jpg)
Flip the board over and cut the tracks leading to each of the base pads as highlighted in this image. You can use a small hobby knife or whatever - just make sure you only cut the tracks that go to the small round pads shown.

(http://mnats.net/images/1176_rev_d_pcb_dividers.jpg)
The second solution is more elegant and I think even easier to do. It is also the better solution as you get to use either transistor footprint as was originally intended. Get a pair of dividers and make sure one point is nice and sharp.

(http://mnats.net/images/1176_rev_d_pcb_dividers_cut.jpg)
Drop the duller of the two points into each round Base pad and run them in a semi-circle around the half of the pad that faces away from the transistor footprint. Do this for all four Base pads in the GR Control Amp section.

After doing either mod, test for continuity. Note that with the first mod, the  unused Base pad is still connected to Ground, but the rest of the circuit should now be separated. In the second mod, the Base pad will test open to ground.

Quote
does this track cut fix the shorted resistor or another one?
Yes! The shorted resistor you found will be fixed as will the other three shorts.

Quote
I'm not sure I knew about the marginal spec on the 2n3707s
I can't force anyone to read my Rev D page but I would suggest reading it if you are joining in on this project. It is linked from the first post of this thread and my Rev D board sales thread. Make sure you check all the Lab threads I've linked from my page too. I'll try to add to this page as I have time to make any additions or corrections that we find along the way.

Again, many apologies for the error on the boards. If anyone feels they can't handle these mods, feel free to send your boards to me (address on the back of the packet) and I'll fix them and send them back to you. I believe that anyone who cannot do the new modification at the top of this post should probably not tackle this project anyway. All boards I send out after today will be fixed before they are sent. Thanks to strangeandbouncy for finding this problem before we all went crazy trying to find the fault.
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 14, 2007, 07:10:25 AM
Mnats,

   thank you so muchh for such a comprehensive reply so quickly! about the 2n3707/8 business, what hfe should they be? are all 3708's going to work or ar we gonna find some of them are too low? Too bad |I already got my 3707's at £2 EACH . . . . .


      ANdyP
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 14, 2007, 07:12:50 AM
hfe 250 ok sorry
Title: 1176LN Rev D DIY
Post by: mnats on February 14, 2007, 03:24:45 PM
Quote from: "strangeandbouncy"
thank you so muchh for such a comprehensive reply so quickly!

I'm just glad you caught the error and that it wasn't too serious in the scheme of things.

Quote from: "strangeandbouncy"
are all 3708's going to work or ar we gonna find some of them are too low?

I don't know. It would seem from the original schematic that they were able to find some 3707s that met the spec (the range is 100 - 400 on the Central data sheet). The 3708s actually have a lower low end (45 - 650) but all the ones I bought in a batch of 25 were above 250.

Measure your 3707s before you give up hope!
Title: 1176LN Rev D DIY
Post by: Sleeper on February 14, 2007, 10:08:25 PM
Hi Mnats, I read your pdf's religiglessly.  I wouldn't want you to think you've wasted your time.  they are really very very informative.

Totally ignore me about the bom...  now I see that the 3708s are even more marginally spec'd (low hfe45).  No biggie here, I've learned my lessons and always order at least 5 times the required amount when buying cheap transistors...  on top of this, I'm making a stereo unit so I like to try and match my hfe left to right  -like q1 left unit and q1 right unit should be very close.


Hey thats a great idea using the dividers to carve out the traces.
 
Kelly[/list]
Title: 1176LN Rev D DIY
Post by: hejsan on February 16, 2007, 09:17:04 AM
Quote from: "tommypiper"
Thanks Ed, Mako and everyone.  Great discussion, interesting project.

I'm looking at this.  It seems fairly straight forward.  (Thanks NYDave)

Quote from: "JdJ"
NYD's Bridged T Schem (http://www.groupdiy.com/index.php?topic=4825&postdays=0&postorder=asc&highlight=dual+1176&start=0)


Sorry for being daft, this attenuator is not balanced, will it still work even if it is only attenuating one of the "phases"?
Would you:
a)  just run the + of the input into this attenuator along with ground, and send the - side un-attenuated into the input transformer?

b) run + and - into the attenuator and have the ground just bypass it

does the transformer following this attenuator have to be much larger than 600ohms for this to work?

Thanks for clearing my mind up,
hejsan
Title: 1176LN Rev D DIY
Post by: Sleeper on February 16, 2007, 12:28:36 PM
Hi Hejsan,
check the purple mc76 schematics...
there you'll see the bridged-t setup as it was implemented in many of the original 1176 revisions.  I the transformer ratio is also on that schematic.

We're assuming that it will work the same now as it did then :wink:

Kelly
Title: 1176LN Rev D DIY
Post by: mnats on February 17, 2007, 12:09:36 AM
Hi - I've posted an easier and better solution to the problem with the boards:
http://www.groupdiy.com/index.php?topic=246397#246397

Should be simple enough for any DIYer :wink:
Title: 1176LN Rev D DIY
Post by: tommypiper on February 18, 2007, 01:14:30 PM
Thanks, Mako.  :thumb:  Looks like piece of cake.

I think many of us are now waiting for the output iron group buy to be offered.  Anything exptected soon?  A timetable?  No worries...  Just wondering when it might be projected to happen, if anyone knows.
Title: 1176LN Rev D DIY
Post by: Sleeper on February 18, 2007, 02:16:32 PM
Tommypiper- it was a piece of cake.
I just did a little work on this last night...
so close to completion... so.... close...
Unfortunately my 2n3707s all tested with hfe around 140-150
The 5088's with a spec'd hfe of 300 to 900 will work regardless.
gotta wait for those.
and then there's those transformers.
Edanderson? are you listening. can we bother you for a quick status update?

Kelly
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 18, 2007, 04:52:10 PM
mine is so nearly done! My2n3707's were ok. Just one thing, apart from output iron, that is,


      Mnats says that the 30v rail is rated at 50ma, the10v rail must be loads less than that, or why use a zener? so why does the bill of parts at gyraf.dk suggest a 25-0-25 rated at 500mA? surly this is more than 10 times too large? I believe in headroom, but thats outrageous! 25VA for, by my reckoning, 2W!!!!!!

   Before anyone shouts at me for having missed the obvious(As Usual!) I have spent at least 3 hours trolloing through all the 1176 stuff.

   CAn anyone expain, or suggest a suitable rating?


   Many thanks guys

  ANdyP
Title: 1176LN Rev D DIY
Post by: edanderson on February 18, 2007, 05:49:23 PM
re: power transformer - in order to get both +30V and -10V DC rails you need at least a 2 x 25VAC transformer; dual 30VAC secondaries would be safer.  look at your actual line voltages where the unit will be installed and leave yourself a margin for day to day dips.

as for the VA rating, while the circuit itself may draw only 50ma, you have to throw some power away for regulation to get that clean 50ma.  and when a 25VA toroid is only slightly more expensive than a 7VA toroid, why not oversize?  the less load you put on the power transformer, the smaller the stray field it will generate, reducing interference headaches.  the transformer will also run cooler and last longer.  the larger transformers are more efficient and less likely to have the output voltage droop under load.


i hope to have some output transformers to sell by the end of the month.  i will post an ad in the black market when they are ready; please do not contact me before then.

ed
Title: 1176LN Rev D DIY
Post by: Sleeper on February 19, 2007, 02:32:42 AM
Thanks for the update Ed.  Please post in this topic when you get the black market up. I'd hate to miss out. :cry:
Cheers and thanks alot for doing the order.
Kelly
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 19, 2007, 04:57:49 AM
Thank you very much indeed. Ed, for that explaination. I hadn't considered either stray field or voltage droop.


   I shall look for 30-0-30v at 25VA


     Thanks,

       ANdyP
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 19, 2007, 04:58:00 AM
Thank you very much indeed. Ed, for that explaination. I hadn't considered either stray field or voltage droop.


   I shall look for 30-0-30v at 25VA


     Thanks,

       ANdyP
Title: 1176LN Rev D DIY
Post by: enthalpystudios on February 21, 2007, 12:10:28 AM
.....hmm...  what to do with 30 160hfe 2n3707's?

****  ;]
Title: 1176LN Rev D DIY
Post by: Sleeper on February 22, 2007, 05:23:52 PM
add 25 more low hfe 3707s here.
besides another fuzz face?
hmmm.
another fuzz face it is.
Kelly
Title: 1176LN Rev D DIY
Post by: JdJ on February 22, 2007, 10:29:18 PM
Just curious,

Are you guys checking the 3707s in the circuit, or with a tester?  I'm wondering if I should socket mine for testing in the circuit as I am hesitant to buy a dedicated tester.  Is there even a socket that will fit the footprint on the board?

Cheers,

Josh
Title: 1176LN Rev D DIY
Post by: Sleeper on February 23, 2007, 12:59:14 AM
tested in the hfe tester of my DMM.
not sure how to test HFE with a circuit, but I'm sure someone around here does. You might try the meta. sorry I couldn't be more help.
still waiting for replacement transistors.
as for the socket you can always cut apart a sipp socket (in line header- like the kind you'll need for the THAT vca chips) but- if you put the low hfe transistors in there I've got no idea if the circuit would not work or if it would just work but poorly- this could be very difficult to troubleshoot.

Kelly
Title: 1176LN Rev D DIY
Post by: JdJ on February 23, 2007, 09:39:34 AM
Testing in the circuit seems to be the only other way to do it, unless you build a jig that replicates the circuit (which seems kind of redundant to me).  I think essentially you are measuring the forward voltage with a set control bias present (via signal generator) or something like that.

[edit] took out needless confusing and possibly incorrect info[/edit]

There are a few threads about it around here, but I was just curious how people were doing it.

Time to go DMM shopping?!

Thanks,

Josh
Title: 1176LN Rev D DIY
Post by: nerd on February 27, 2007, 12:12:28 AM
edanderson - I don't know if you are using this thread for a count on output transformers, but if you are, please count me in for two.


What are the rest of you guys going with for input transformers? Are you trying to source the UTC o-12s? There are two on ebay now for $200. That seems pricey. (or is it, I don't know?) There was talk of the altran copy (C-3837-1) earlier in this thread, but that idea seems to have died off.
Title: 1176LN Rev D DIY
Post by: Sleeper on February 27, 2007, 01:08:49 AM
the 0-12 input transformers are wired 500 to 250 ohm and I think they are rated at +8dbm
pretty much any good 600 to 600/300 transformer should be great.
for example, you can find utc a21s for much less money.
I used some triads on my g1176 and they sound verry nice.
have 2 more for this one.  I'll bet edcors would work fine.  
The mounting is offboard so there aren't any footprint worries.
go nuts.

got my 2n3708s today. all tested out around 300hfe.
onward!

Kelly
Title: 1176LN Rev D DIY
Post by: edanderson on February 27, 2007, 10:00:21 AM
Quote from: "nerd"
edanderson - I don't know if you are using this thread for a count on output transformers, but if you are, please count me in for two.


i'm not using this thread to keep track.  i should have some output transformers in about a week.  look for an ad in the black market.

Quote from: "nerd"
Are you trying to source the UTC o-12s? There are two on ebay now for $200. That seems pricey. (or is it, I don't know?)  There was talk of the altran [utc o-12] copy (C-3837-1) earlier in this thread, but that idea seems to have died off.


$100ea for an o-12 is quite excessive.  $25ea is more like it, but i guess whatever people will pay.  

the escalating prices on o-12s is why purple started using the altran part, which we had done as a custom part.  the problem with using the altran part for the mnats board is that it is PCB mount, and there is no place for it on the board.  i haven't found any can clamps that would work very well, so mounting would have to be on a piece of perf board.  the pin spacing is 0.15", different from most perf which is 0.1" so even that will be a pain.  i suppose someone could make up an input PCB, with pads for various input transformers, input attenuators, etc.

if there is any interest in the altran o-12, i can put together an order, but so far i havent seen the need.

ed
Title: 1176LN Rev D DIY
Post by: mnats on February 27, 2007, 03:10:06 PM
There were a few reasons I didn't want to mount the input transformer on-board. One is that I was unsure what people wanted to use there and thought it would be best to wait until some options had been explored. Another was that presumably a fixed position would limit the mounting options for the board in relation to the power transformer especially for dual/stereo configurations. The main reason, however, was that my board design was done and adding a transformer footprint to it without an extensive rework would have looked like something had been tacked on as an afterthought.

My thinking at the time and now is to sort out the common transformers/input configurations that work well then make a separate board - possibly with several transformer footprints - to create a clean way of mounting the input transformer without having to worry about turning the main board this way or that to avoid interaction with the power transformer. Hope that makes sense.

When we get the input circuit sorted and have a few nice choices then I'll do a separate PCB. If everyone decides to use the original UTC well there won't be a need for a PCB at all. Personally I'm very interested in the Altran part.
Title: 1176LN Rev D DIY
Post by: kazper on February 27, 2007, 03:42:16 PM
I would also be in for the Altran. I don't want to pay over $100 for a transformer or buy two when I want to do just one unit.

One may be able to just hose clamp it to a couple metal supports. A custom board from a self etch may also work just fine. It may be a reason for me to actually do a self etch. I know I could think of something that would look nice without costing a arm and a leg.

Count me in on the Altran Transformer for one possibly two. It all depends on if I can source another T-pad. I definitely will grab a output transformer or two from you for this project.

BTW Mallory sells a 600 ohm T-Pad for around $100 Each new.
Title: 1176LN Rev D DIY
Post by: matthias on February 27, 2007, 03:56:17 PM
I will build mine with the new that 1200 line receiver ics at the input

but I've got a nother question. refering to the original revD schematic you should also match the output transistors

so what about that..??
Title: 1176LN Rev D DIY
Post by: strangeandbouncy on February 27, 2007, 06:17:02 PM
edanderson,

   we wait like hungry cuckoos, mouths open in anticipation . . .

   seriously, personally, i will be extremely greatful if you can produce a suitable transformer! I am surely not alone, - You the Man!

  Kindest regards,

    ANdyP
Title: ditto that
Post by: shabtek on February 27, 2007, 07:16:08 PM
ye-yass,

i'm interested in a few i's and o's!!!
Title: input output transformers G1176 D
Post by: dmix on February 28, 2007, 09:58:14 AM
Just use for input cinemag CMMI-2C @ $60.85 each and for output CM96731 @ $47.35 each

purchase directly from cinemag
Title: 1176LN Rev D DIY
Post by: mnats on March 03, 2007, 07:10:13 PM
dmix - what quantities are you quoting Cinemag prices for? My understanding was they had a minimum quantity of 5 at that price for the opt.

So you've tried the CMMI-2C on the input in this circuit? What can you tell us about how it compares sonically to the UTC ouncer?

(http://www.geocities.com/m_natsume/images/1176_rev_d_cinemag.jpg)

I received my iron from Purple this week so I finished off one fabricated board to test the output circuit. It all works fine. I wouldn't suggest using anything but the Cinemag on the output. Though it 'works' with a normal output transformer or with the feedback winding removed the performance is badly compromised as you would expect.
Title: 1176LN Rev D DIY
Post by: edanderson on March 03, 2007, 07:54:30 PM
re: the CM96731 output, i was also told that there was a 5pc minimum order, which is why i went ahead and ordered some to sell to people with mnats boards.  i will check with tom and david; if they are willing to sell single transformers to everyone, then i will get out of the way.  david said they were going to ship my order this week, so i should have them pretty soon.  please do not PM me; i will post an ad in the black market as soon as they are available.

as for using the cmmi-2c as an input, yeah it probably will work, but i doubt it will sound much like an O-12 (which could be a good thing in some cases!).  i did suggest it back in 2005 (http://www.groupdiy.com/index.php?topic=10611) but i think that there are better options available now.

ed
Title: 1176LN Rev D DIY
Post by: tommypiper on March 04, 2007, 12:24:44 AM
Hi Ed, I already went over it extensively with David some time ago; they will not sell small quantities individually.  David suggested a group order for those who want small quantities.  I was going to consider a group order or buy a bunch and offer the extras, but you beat me to it as I was short on credit card headroom for a while.  :grin:  Glad we're all moving forward.

Mako, good to hear you finally got your Purple iron and everything is working.  :thumb:

I may use a Lundahl or experiment with 1:1 types for the input.
Title: 1176LN Rev D DIY
Post by: thenovice on March 04, 2007, 01:00:30 AM
so what is the best bet for the output then?
Title: 1176LN Rev D DIY
Post by: Sleeper on March 04, 2007, 01:37:27 AM
Sounds like the ONLY bet is to wait for Ed, unless you're buying 5 direct.

Kelly
Title: 1176LN Rev D DIY
Post by: Nadege on March 04, 2007, 08:54:49 AM
I've already build a 1176 using your previous revission board and didn't
take time to carrefully read all the thread about your rev D before ordering
boards...
(It's a bit stupid)
I'm VERY confussed about input and output transfo wiring and sourcing. Would
the rev D work with the OEP I've used in the other 1176 as I'm really happy
with the sound of these ??
How to wire them ?  I'm also very confussed about the input pot of the
compressor as it is totally different from the previous one....
Could you help me a little bit (wiring diagram???) pictures of finished
works,...
Thanks a lot

It seems that the cinemag output is the best thing to do, If anybody here is planning a groubuy i'll be VERY interessted
Title: 1176LN Rev D DIY
Post by: kato on March 04, 2007, 09:58:29 AM
BTW - the 3707's I ordered from mouser in jan 2007 all tested in the 150-170 hfe range. (too low.)
Title: 1176LN Rev D DIY
Post by: Mailliw on March 04, 2007, 11:31:41 AM
Why are the primary/secondary impedances on the orignal input transformer (and suggested replacements) so low if the 1176's input impedance is 20K?
Title: 1176LN Rev D DIY
Post by: Sleeper on March 04, 2007, 06:11:35 PM
Hope I can save Mnats a little time here.
There is really well drawn info about input and output impedences and wiring within the purple audio schematic.  there are links littered all over this thread to that.

The OEPs will work.

there will be transformers on the blackmarket soon... the info is only a couple of posts back.  

Kelly
Title: 1176LN Rev D DIY
Post by: dmix on March 08, 2007, 06:52:01 AM
Quote from: "mnats"
dmix - what quantities are you quoting Cinemag prices for? My understanding was they had a minimum quantity of 5 at that price for the opt.

So you've tried the CMMI-2C on the input in this circuit? What can you tell us about how it compares sonically to the UTC ouncer?

(http://www.geocities.com/m_natsume/images/1176_rev_d_cinemag.jpg)

I received my iron from Purple this week so I finished off one fabricated board to test the output circuit. It all works fine. I wouldn't suggest using anything but the Cinemag on the output. Though it 'works' with a normal output transformer or with the feedback winding removed the performance is badly compromised as you would expect.


Hi Mnats, i ordered 2 of each and then mentioned to David Green from cinemag about some other DIYers that might be interested, he didn't mention anything about a minimum order, but i did buy 2 of each.

the CMMI-2C is 1:2 will use it in reverse

i can't tell you sonically as yet, will receive the shipment shortly

dmix
Title: 1176LN Rev D DIY
Post by: ap123 on March 10, 2007, 07:30:05 PM
Can someone tell me the part numbers for those blue surface mount screw clamp connectors?  Those aren't on the BOM that Kato made and they look quite handy.  Also, in the rev d schematic I can't find the input pot.  Is this before the input transformer which isn't on the schematic?  I plan on using the O-12 reproduction from purple audio.

My last question is: I already stuffed the main PCB and completed the PSU section but now I've decided to build a dual mono unit.  I'm using the Avel Lindberg Y236107 (30VA 30+30) power transformer.  Is it bad practice to send the secondaries of the avel to two independently regulated PSUs rather than go through one PSU (as I would on the mnats psu pcb)?

And finally, am I crazy to try to fit these in to 1U?  I don't see any problem with it except finding 1U tall VU meters.
Title: 1176LN Rev D DIY
Post by: kazper on March 10, 2007, 07:58:28 PM
Sifam Al-19 then code for inside outside, what ever cutout etc... format or you can use the Led VU's from the http://www.picocompressor.com/picocomp/grmeter.htm

There under terminals in the mouser book.
I'm not sure where your located but the main thing is the correct spacing between terminals. I can measure it and post later for everyone or mnats probably knows it off the top of his head.
Title: 1176LN Rev D DIY
Post by: ap123 on March 10, 2007, 10:00:03 PM
kazper, thanks!  I think it will be the Sifam Al-19WF.  Total vertical clearance is 40.6mm it looks like.  I need to make sure this will fit in a par-metal series 10 1U.  I have one on order but the clearance is unclear in the PDF on the par-metal site.  I will post my findings.

Terminal spacing on my rev d pcb is 5mm on center.

Thanks again...I really appreciate it.
Title: 1176LN Rev D DIY
Post by: Sleeper on March 10, 2007, 11:22:21 PM
TERMINAL BLOCKS

Here's the part numbers from my digikey order.
these fit the boards but they were just a little tight- the pins were square and I had to take a small file and round off the edges. took about 10 minutes for 2 boards, no big deal really

281-1436-ND   CONN TERM BLOCK PCB 5.08MM 3POS        
281-1438-ND   CONN BLOCK TERM PCB 5.08MM 6POS

Kelly
Title: 1176LN Rev D DIY
Post by: kazper on March 11, 2007, 01:23:59 AM
you could also enlarge the whole but I'm unclear of how to properly do that without messing up.

I just helped another member and seen a Par-metal 10 series case for the first time. They are not exactly 1.75" cases more like 1.5" and there sheet shows this info. We used a nibbler to cut the top and bottom lip, that I got from Radio shack a few years ago and it worked very slick for what we needed to do. this was a GSSL project and the meter was a tight fit but it did fit. Some precision tools go a extra long way with this, but you don't have to break the bank.
Title: 1176LN Rev D DIY
Post by: ap123 on March 11, 2007, 01:59:59 AM
I was worried about that with the par-metal specs.  Those PDFs don't appear too specific.  I was going to order my front panel but I need to make sure the system holes are ok.  I sure wish frontpanelexpress had a gigantic user-based macro library.  This forum should have an FPE macro library ;)

On the terminal blocks, the leads on the 281-1436 aren't specified in the catalog.  However, other black blocks have 1.2mm which look too large according to my trusty ruler.  ED1624-ND (3 pos) and ED2223-ND (6 pos) are not only blue (like everyone's pics) but have lead diameters specified as .9mm.  Could these be what everyone has?
Title: 1176LN Rev D DIY
Post by: Sleeper on March 11, 2007, 03:44:21 AM
If you found something with a .9mm I'd say that should do well.
.3mm seems about what I had to shave... it wasn't much.
Cheers
kelly
Title: Re: Terminal Blocks
Post by: kato on March 11, 2007, 10:35:04 AM
Re: Terminal Blocks

Molex Brand fits. The spec sheet for Tyco/Buchannan brand is wrong. They claim 1mm width but parts arrived w/1.4mm wide pins. Mouser offered to have a tech measure the pins on the Molex before sending them out. They arrived and fit perfectly. (Their spec sheets says .89mm and it's still a snug fit.)

Mouser | 2 position | 538-39880-0302 | qty: 1/channel
Mouser | 3 position | 538-39880-0303 | qty: 7/channel

The above two fit mnats board with no filing required.
They are interlocking so you will lock two 3-position blocks together for the 6's. Also, they are black in color matching mnats board nicely.
Title: 1176LN Rev D DIY
Post by: ap123 on March 11, 2007, 06:13:32 PM
Thanks kato...awesome.  

Now I'm curious what pot to use on the input.  I can't find this on the rev d schematic because I believe the input pot goes before the input transformer(?).  I have:

R55: 25k linear (attack)
R56: 5M linear (release)
R23: 250k audio/log (output)
R??: ?? (input)

I'm planning on using the 0-12 reproduction through purple.

And finally, I swear I posted this question already but I can't find it.  It is possible that I dreamed posting this question...if I did post this already please accept my apologies.  I've been a bit consumed by this forum lately...ugh.
Title: 1176LN Rev D DIY
Post by: dmix on March 11, 2007, 06:27:40 PM
Quote from: "ap123"
Thanks kato...awesome.  

Now I'm curious what pot to use on the input.  I can't find this on the rev d schematic because I believe the input pot goes before the input transformer(?).  I have:

R55: 25k linear (attack)
R56: 5M linear (release)
R23: 250k audio/log (output)
R??: ?? (input)

I'm planning on using the 0-12 reproduction through purple.

And finally, I swear I posted this question already but I can't find it.  It is possible that I dreamed posting this question...if I did post this already please accept my apologies.  I've been a bit consumed by this forum lately...ugh.



its a T600 attenuator on the input

check the thread

http://www.groupdiy.com/index.php?topic=10593
Title: 1176LN Rev D DIY
Post by: kato on March 11, 2007, 06:32:27 PM
Quote from: "ap123"

I'm planning on using the 0-12 reproduction through purple.


?? Purple stopped selling the 0-12 repro to DIYers on Dec. 31st 2006.
(Unless I missed something.) Search this thread for info on the attenuator / input pot. There's no readily-available, off-the-shelf solution for this one.
Title: 1176LN Rev D DIY
Post by: ap123 on March 11, 2007, 06:41:10 PM
That thread was frighteningly inconclusive for someone with my level of experience!  :wink:

Will this work?

http://www.duracap.com/controls_switches/audio_attenuators.pdf
Title: 1176LN Rev D DIY
Post by: ap123 on March 11, 2007, 06:42:03 PM
Purple told me the lead time was 2 weeks on the input and output transformers.
Title: 1176LN Rev D DIY
Post by: dmix on March 11, 2007, 11:40:02 PM
Quote from: "ap123"
That thread was frighteningly inconclusive for someone with my level of experience!  :wink:

Will this work?

http://www.duracap.com/controls_switches/audio_attenuators.pdf


 
yes the T Pad Attenuator cat number :T600 will work
Title: 1176LN Rev D DIY
Post by: AnalogPackrat on March 12, 2007, 12:15:39 AM
Hey ap123--could you post a price quote on those Mallory T600 units if you get one?  I might be interested in a couple.

Thanks,
A P
Title: 1176LN Rev D DIY
Post by: edanderson on March 12, 2007, 12:43:33 AM
those mallory t600s will work; i found some surplus a few years ago and a few people built purple units with them, SSLtech for one.  they are wirewound and pretty stiff feeling, but good quality.  new i think they go for around $100 the last i checked.

ed
Title: 1176LN Rev D DIY
Post by: kazper on March 12, 2007, 07:22:03 AM
I had a quote for them from the only place that popped up on google with them and it was like $105 each a few weeks ago before I found a few on the bay.
Title: capacitor too big
Post by: kato on March 12, 2007, 07:29:01 AM
for anyone using my parts list -
capacitor C22 is too large to fit in the footprint. It bumps into resistor R4.

Not major - you can offset R4 a bit to make it fit. Or use a smaller replacement for C22 if you don't want to de-solder R4 and replace it. (this is assuming you solder resistors first.)

I apologize for the error. I chose the polyprop wima without noticing it's excessive wideness. My parts list has been updated with the polyester wima for that value.

http://nimbleswitch.com/diy/1176_revD_parts.html
Title: 1176LN Rev D DIY
Post by: nerd on March 12, 2007, 12:00:21 PM
I just can't bring myself to spend $100+ on an attenuator. I think I am going to use a 12 position 2 pole switch and do a bridged T with ~4.5db steps. I know that that is probably too coarse of an adjustment, but most things I will be using it with will have some sort of output level adjustment.

I was going to use finer steps (2db 12 positions) figuring I would only attenuate the signal within a limited range anyway, but it doesn't seem like you can start at zero attenuation +2db +2db... It looks like there is almost always some attenuation going on.. So the question here would be, well... where to start? It looks like you calibrate the meter with the input set to 24db. So, 14db +2db +2db... up to 34db seems like it would work, but I am not confident enough with this assumption to run with it.

Any thoughts?
Title: 1176LN Rev D DIY
Post by: ap123 on March 12, 2007, 01:28:23 PM
Kato, I just went with the flow... :thumb:

(http://www.artistandrepertoire.org/misc/IMG_0525.jpg)
Title: 1176LN Rev D DIY
Post by: kato on March 12, 2007, 01:39:44 PM
Quote from: "ap123"
Kato, I just went with the flow... :thumb:

(http://www.artistandrepertoire.org/misc/IMG_0525.jpg)


Thanks for being flexible! I had no idea how honkin' big those were going to be.

The experience has taught me to check the width column in the catalog even on parts I think I know...
Title: 1176LN Rev D DIY
Post by: ap123 on March 12, 2007, 01:44:35 PM
nerd, I found this the other night and thought about emailing these guys: http://www.marchandelec.com/att.html  Maybe they could whip up a T600 kit or something.
Title: 1176LN Rev D DIY
Post by: timmygrimm on March 12, 2007, 02:19:26 PM
Quote from: "ap123"
nerd, I found this the other night and thought about emailing these guys: http://www.marchandelec.com/att.html  Maybe they could whip up a T600 kit or something.


I was thinking this might be cool for a group buy, but I guess they only do stepped? I can't decide how I feel about that.

Tim
Title: 1176LN Rev D DIY
Post by: nerd on March 12, 2007, 03:13:54 PM
Quote
nerd, I found this the other night and thought about emailing these guys: http://www.marchandelec.com/att.html Maybe they could whip up a T600 kit or something.


I only looked briefly, so I may be wrong, but I don't think those are constant impedance attenuators. I think they are just stepped potentiometers.

For less than the $50 it costs for the 24 position attenuator they have posted, you could build one. Electroswitch has a DP24T switch for around $36 from mouser. If you are the one building this into a 1u rack, I don't think that switch will fit though. I think it was more than 2 inches across. That is my problem too. I am (attempting to) building a dual in a 2u.

I think I am going to go with my earlier idea with large steps. Rotary switches make a big jump in price and size after 12 positions.  That is, unless someone makes a good argument that it only really needs to work in a smaller 24db range, then I would use the 2db steps across that small range, or someone finds a source for an inexpensive attenuator or switches.

FYI: I am a noob, so don't take my posts too seriously. This is my first DIY since some paia kits in the 80s.
Title: 1176LN Rev D DIY
Post by: kazper on March 12, 2007, 05:36:56 PM
maby a group buy for a tpad style unit or switches. I will again at the local surplus stores for something and see if there is a inexpensive fix to help keep the projects price point low. Also keep a eye out for ebay, I got my T-pads there.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 12, 2007, 11:17:28 PM
Hey I built and cloned my own PAIA kits also in the 80's they were fun :) I believe I still have an "Axe Grinder" laying around somewhere for guitar :)
Title: 1176LN Rev D DIY
Post by: ap123 on March 13, 2007, 08:52:35 PM
Are there any other options for the input attenuator beside the ever elusive T600?  Can you have, say, no attenuator?  For instance, what is happening here (http://www.geocities.com/m_natsume/1176-wiring.html) under the section "Input Wiring Option B (transformer balanced input)?"  That doesn't look like a big fancy $100 bridged attenuator.
Title: 1176LN Rev D DIY
Post by: kazper on March 14, 2007, 10:14:21 AM
NY Dave's switch setup about the best lo cost option next to finding one on ebay.
(http://electronicdave.myhosting.net/miscimages/600bridgedt.gif)

or read this thread
http://groupdiy.com/index.php?topic=10593&start=30&sid=1ab9426da227a8425f56e7fc18df79e5
Title: 1176LN Rev D DIY
Post by: enthalpystudios on March 14, 2007, 11:25:12 AM
i know this is diy, and i know that we all have short wallets at times, i know i do, but if you indeed want to build a *rev D* clone 1176, that 100 bucks (tops, probably more like 60-70), is not really that big of a deal when you factor in the money you save doing it yourself.  if your time is valuable in a the sense of real dollars and cents, it'll be cheaper to buy one.

  plus surplus they can be found for 5-10 bucks if you aren't pressed for time, and keep you eyes open and the swap meets and ham fests and surplus joints, whatever.


stepped is of course a fine alternative....   but running the signal straight into a tx, ESPECIALLY if its a utc o-12 or clone of an 'ouncer' unit, is NOT a good idea....    Especially, again, if you are recording in a modern, bridging, electronically balanced world where impedances can run high.

they didnt use the attenuator just to off put cloners, they had a very good reason to do so.  the electronically balanced input or a stepped or variable bridged tee are the only options available in my book, otherwise i'll build a different compressor, with a different design.
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 11:39:08 AM
Guys, if you need your 600 ohm bridged T, there are Clarostats here that match one of the two Purple solutions on the Purple schematic.  They're only $30.  This was mentioned back around page 8 or 9 in this thread.  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=013&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=230002096428&rd=1&rd=1
(Edit: this sale is apparently closed.)

Or are you looking for something different?
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 11:43:33 AM
Quote from: "ap123"
Are there any other options for the input attenuator beside the ever elusive T600?  Can you have, say, no attenuator?  For instance, what is happening here (http://www.geocities.com/m_natsume/1176-wiring.html) under the section "Input Wiring Option B (transformer balanced input)?"  That doesn't look like a big fancy $100 bridged attenuator.


That's a different circuit.  

Look at my previous post for a 600 ohm solution.  (EDIT: Sorry, my error, the sale is apparently closed.)

Otherwise,  I think using a modern transformer with a pot will work.  I plan to try that route myself.  

I beleive Mnats has also said you can go straight in unbalanced without a transformer.  

We'll need to experiment but it should work with several options.
Title: 1176LN Rev D DIY
Post by: ap123 on March 14, 2007, 01:32:48 PM
There is also a Clarostat CIT 600 that Leed's has mentioned as an alternative to the Mallory T600.  It is three gang.  This will work, too, I think.  Is this clarostat the closest thing to what UA is having PEC mfg now?

Yeah I saw that auction the last time I was on page 8 or 9...it was ended early but gee I can't imagine why.  :?

I agree completely on the price issue.  Spending $500 on a DIY 1176 is good fun.
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 02:02:39 PM
Edited: The ebay item is closed, my mistake.  I had posted that it was still open.
Title: 1176LN Rev D DIY
Post by: ap123 on March 14, 2007, 02:47:27 PM
We must be looking at different auctions.  This one has said "The seller ended this listing early because the item is no longer available for sale" since I found it days ago.  I get the feeling (loud and clear) that discussing options and availability for the T600 has become an inconvenience for some of you.  Please realize that some of the threads on this topic are a year old and contain broken links and incomplete discussions (or link to auctions that have long since ended or links to threads that have been mysteriously deleted altogether like the one that contained a pic of the PEC T pad).

NewYorkDave was kind enough to re-post his schematic for his switched attenuator and I appreciate that greatly.  His posts were over 2 YEARS old and I'm sorry I couldn't find them using my many search queries.

Does anyone agree that these would be appropriate additions to the 1176 meta?

http://www.groupdiy.com/index.php?topic=4825
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 03:32:18 PM
Oh, you're right about it closed, my mistake, I'm sorry.  I would contact the seller anyway and ask if he has the parts available.  

It doesn't bother me to discuss the 600 ohm stuff, I just thought the parts were still available.

However, I also think it makes sense to consider that the original 600 ohm implementation is not the only way to skin the cat.  And one shouldn't lock oneself into just one idea, particularly if parts availability is an issue.  Cloning  may not be your best solution.

This is DIY, not CIY.  Celebrate your freedom to try something new.
Title: 1176LN Rev D DIY
Post by: ap123 on March 14, 2007, 03:50:41 PM
Perhaps I can get this to work:

http://stores.sacelec.com/sacramentoelectronics/detail.jsp?attribute3=Attenuators&category=Audio%2FVideo&subcategory=Accessories&-skipRows=13

Edited: This link now points to the next item listed in the category as the item is no longer available on the site.

This place is only 20 miles away from me.  What are the chances.
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 04:31:26 PM
Quote from: "ap123"
Perhaps I can get this to work:

http://stores.sacelec.com/sacramentoelectronics/detail.jsp?attribute3=Attenuators&category=Audio%2FVideo&subcategory=Accessories&-skipRows=13

This place is only 20 miles away from me.  What are the chances.


Looks like the real deal to me.  Give it a go.
Title: 1176LN Rev D DIY
Post by: audioforge on March 14, 2007, 04:58:31 PM
i used this one at the output att. in my cca la1d clone. beware they re big. 42mm diameter and 55 mm long.
keep us in touch.
ps edanderson in this black market thread
 http://www.groupdiy.com/index.php?topic=21452
have sold omeg tpad : "3 600ohm non-bridged T-pads - $8ea SOLD
i had these made by omeg, similar to the purple mc77 t-pad
they work fine, but i hate the plastic shaft, and i don't like the feel "
maybe a group buy from omeg could be done......
 :wink:  audioforge
Title: 1176LN Rev D DIY
Post by: tommypiper on March 14, 2007, 11:18:36 PM
These ones from ap123 are not Omeg.  They are Clarostat which have a solid feel and metal shaft.  Price around $30 is very reasonable.

Funny, but the link is now showing a 1000 ohm part.  Maybe the 600s sold out?  Or they have dynamic URLs that change all the time.

ap123, please fill in your location information.  Where are you located, near Sacramento?
Title: 1176LN Rev D DIY
Post by: ap123 on March 14, 2007, 11:45:56 PM
Yes.  I noticed that earlier and intended to come back and remove the link.  I think when one item sells out it goes to the next item in the category.  You are correct there was only 1 in stock.  I called and asked about more and he checked his network of surplus parts and nothing turned up.  He mentioned being in some group of surplus electronics suppliers that share inventory resources.

Yes.  I am about 20 minutes east of Sacramento.  I will fill in the location info sorry about that.

Edited: I also wanted to add that Leed's Radio in NY has some T pads listed on their site.  I emailed them and they do claim to have one in stock for $52.  I don't know any more details on it.
Title: 1176LN Rev D DIY
Post by: tommypiper on March 15, 2007, 12:48:56 PM
Thanks.  Well, I think we've covered this now.  

You gots choices.  1) Contact that ebay seller in the chance he still has some.  2) Track down supplies of that Clarostat part, (I think it was part number CIT 600)?  3) Build one yourself, maybe something like NYDave's idea(s) or in the separate 600 ohm T thread http://www.groupdiy.com/index.php?topic=10593&sid=d16418abcfe1519b3eaa955c39721c1c.

Or... 4) think beyond the world of 600 ohms.  

Choices choices.  

Once other guys get further into their builds you may also be seeing different takes on it.  

Remember to think different.  Innovation leads to new things, new sound.  

Back to building.  Good luck.  Hope it was helpful.

Cheers.
Title: 1176LN Rev D DIY
Post by: enthalpystudios on March 15, 2007, 01:14:31 PM
just want to say real quick though that there's a whole circuit behind those first two parts, and it was designed by a very bright man who intended it to work a certain way, and there are a bunch of loose threads about things that 'don't work the way i want,' 'don't work the way they should,' or 'doesnt sound as cool as the one at my dude's studio' etc etc

one way or another, I can't expect to replace parts in a schematic that had gone through 4, 5, 6, 7, whatever revisions and expect the world....   and man, with the time i've realized it takes to build stuff really well, if i can't get a part or can't pay the price, i'm not going to spend the time anymore.

so thats all....   there's nothing wrong with a 5532 input 1176.  it sounds wonderful to my ears.  i mean thats probably what happened to urei...  the same thing that happens to me...  "these attenuators are getting really expensive"    and instead of slapping on something that might work, they used a chip.  big deal...  if i find at a good price some old 600 ohm t attenuators, i'll use em....  if i find enough spare cash to buy new ones, i'll buy a pair.  but i'm not gonna put any time into a rev d 1176 without em.

/rant


i think that a fet compressor with input and output transformer would be an awesome thing to have. abosolutely....     and actually, the adr stuff is perfect example.   high-ish, maybe even 10k, input impedance, 600 out, standard easy to get transformers, all pots are just 'pots'

setup is probably a little tougher, but it can't be that bad.

i've been wanting to try and make a board for adr f600 for a while now, i have a scan of a friends pcb, and tons of notes, and some awesome pics from kid squid, maybe i should get off my ass
Title: 1176LN Rev D DIY
Post by: enthalpystudios on March 15, 2007, 01:15:15 PM
not that innovation isnt a wonderful idea....  i'm just not smart enough to intelligently innovate

too much to learn from the classics yet
Title: 1176LN Rev D DIY
Post by: joellegros on March 15, 2007, 05:11:48 PM
Hey guys, I've been reading this thread with a lot of interest.  I just noticed an ebay for 10 Mallory T600 attenuators.  Maybe we can all benefit from this if one wins the auction and divides the final price by 10 plus shipping to sell to the rest of us?  

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120098046095&fromMakeTrack=true

-Joel
Title: 1176LN Rev D DIY
Post by: kazper on March 15, 2007, 08:14:34 PM
I will bid on them and we can go from there, I will start with a max of $200 and we can hope they end for allot less than that. Bids up, please don't jack up the price as it will raise the price of the units here. I want 3 of them. so there would be 7 left up for grabs after the auction.
Title: 1176LN Rev D DIY
Post by: gevermil on March 15, 2007, 08:44:19 PM
im in for one
Title: 1176LN Rev D DIY
Post by: joellegros on March 15, 2007, 08:47:43 PM
Quote from: "kazper"
I will bid on them and we can go from there, I will start with a max of $200 and we can hope they end for allot less than that. Bids up, please don't jack up the price as it will raise the price of the units here. I want 3 of them. so there would be 7 left up for grabs after the auction.


I would definitely like two please.

-Joel
Title: 1176LN Rev D DIY
Post by: ap123 on March 15, 2007, 09:20:05 PM
I already offered him $250 through a buy it now but he didn't respond.  I was just going to resell them on the black market for $25/pop.

Someone will need to snipe the auction so you should all settle on a lone sniper  :twisted:  You can't win an auction unless you're around to bid in the last 10 seconds...unfortunately...ugh...I miss 1997.
Title: 1176LN Rev D DIY
Post by: Bri on March 15, 2007, 10:03:31 PM
I'll be in for one, if everything works out.

--Brian
Title: 1176LN Rev D DIY
Post by: kazper on March 15, 2007, 10:30:53 PM
cool. Let's see how it goes and we will work it out when we get there.

I went to a place today in portland and I really need to go back and look with a multi-meter at some of the pads they have in there shop. It's a amazing little place that is like it is in a time capsule. I did manage to grab a 19" rack case that will do the trick for my PM1000 thats been collecting dust.
I also grabbed a few tubes for my lA2A, G9 and Pultec upcoming projects.

If any locals are interested it called R5D3 and you need to go there with allot of time to spare.
Title: 1176LN Rev D DIY
Post by: audioforge on March 16, 2007, 06:39:33 AM
hi i saw this malory tpad on ebay yesterday.as leeds didn t have anymore thoses i need one for a la1d  tube limiter (output pad).they are wirewound and handle 10w .a better application for such a circuit than a 1176 inputpad.
please keep me one....
audioforge
Title: FS: CM-96731 Output Tranformer
Post by: edanderson on March 16, 2007, 03:22:59 PM
PLEASE DO NOT PM ME!

edit: SOLD OUT
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 16, 2007, 04:46:40 PM
You can count me in on a Tpad also. It's obvious whoever bids on them won't be stuck with any! ;)

Thanks,
John
Title: 1176LN Rev D DIY
Post by: Lowfreq on March 16, 2007, 06:45:02 PM
Sweet, thanks ed!! :thumb:

Mula all sent.... Great price on these too...... :grin:

Nice!!
Title: cinemag
Post by: safe as milk on March 16, 2007, 06:56:49 PM
hi ed,
money sent & thankyou for organizing this.

cheers
Title: 1176LN Rev D DIY
Post by: Bri on March 16, 2007, 08:18:12 PM
Thanks Ed!

--Brian
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 17, 2007, 07:21:45 PM
Thanks from me 2 Ed :) money sent...

Cheers


(Edit) Recieved yesterday. Thanks again for helping everyone and the super fast shipping! Two thumbs up  :thumb:  :thumb:
Title: Mnat Rev D w/original input stage?
Post by: kdawg on March 19, 2007, 03:07:31 AM
I happen to have a UTC o-12 transformer and a PEC 600 ohm dual deck UA replacement pot and was wondering what the correct wiring / resistors should be if I was going to mate it with the new Mnat Rev D board. I see a 270R resistor already there across the input to ground.

I built the other rev Mnat board a long time ago but added that o-12 input stage - was never quite sure if it was wired correctly though.

thanks
-kdawg
Title: 1176LN Rev D DIY
Post by: kazper on March 22, 2007, 01:56:28 PM
Well someone sniped the bid away from me. It looks like they have a big appetite for 600 ohm T-pads.
Title: 1176LN Rev D DIY
Post by: ap123 on March 22, 2007, 04:48:15 PM
I did snipe but I was not the lone sniper!  I did not win; that's how I know.  I am disappointed to see that the winner was not a member of this forum.  Perhaps it was a surplus shop.

I have been in touch with the seller and he has more units.  He sold me 10 for $225 which I intend to sell on the black market for $22.50+shipping.  I am not going to post this on the black market until I have them in my possession.  Apparently he has more in storage but they're buried in a storage unit packed floor to ceiling with NOS ham stuff (a gold mine, if you will).  The guy is extremely cool and very supportive of the DIY spirit.  He said he couldn't resist as most of his personal ham equipment he built himself.  Newark now charges $155 for these!  Ugh.  That should speak volumes for how cool this guy is.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 22, 2007, 10:53:17 PM
Wow that's a cool guy.

I didn't bid either didn't want to jack the price up. But I'll keep my eye on the black market unless I can pre order one. Let me know.

Thanks

  Oh and I finished my board today. A real beauty! Thanks Mnats :)
Title: 1176LN Rev D DIY
Post by: kazper on March 26, 2007, 07:17:14 PM
I was trying to pick up a few output transformers from cinimag and there out of stock for a few weeks. I think it will allow a few of us more time to scrounge for t-pads. Just passing the info to the list. Maybe Ed scored there last few units and caused the lack of transformers..
Title: 1176LN Rev D DIY
Post by: ap123 on March 28, 2007, 09:17:26 PM
http://www.groupdiy.com/index.php?topic=257364#257364

As promised here is my notification in the rev d thread about the 9 T600 attenuators I have on the black market.

[sold out]
Title: 1176LN Rev D DIY
Post by: ap123 on March 29, 2007, 02:12:21 AM
8 iterations of king crimson red later and I finally got audio through the mnats rev d.

edandersen *did* at one point suggest the radio shack 1:1 isolation transformer...and at $3 I couldn't resist.  I can't listen to my recording test because I don't have any monitors beside cheap headphones, however, I will say that the radioshack "greenbud" (it's green and weighs exactly 1/8 oz, really!) is conservatively rated at 300Hz to 5KHz.  Surely lower than 300hz is passing here.  This file is a martin d-something > sm-7 > chandler germ >  1:1 Isolation Transformer (http://www.radioshack.com/product/index.jsp?productId=2103994&cp=&sr=1&origkw=transformer&kw=transformer&parentPage=search) >  mnats 1176 rev d > CM-96731 > apogee ensemble.

1176test2.mp3 (http://www.artistandrepertoire.org/misc/1176test2.mp3)

Please excuse my lame noodling I'm really tired.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 29, 2007, 09:47:08 PM
That sounds good :) maybe we can add a IRON switch to the faceplate for switching input trannys! LOL I can't believe that thing is only 3 dollars. And Congrats for getting it up and running!
    :thumb:  :thumb:
Speaking of input transformers. I still haven't decided what to use. What is everyone else using on their version? I almost bought an 0-12 but got outbid. I am now thinking about getting something else that is more readily available. Any suggestions? I did some reading but came to nothing conclusive. I was kinda leaning toward keeping it fairly original sounding...
Title: 1176LN Rev D DIY
Post by: ap123 on March 29, 2007, 10:34:10 PM
I can't really tell how the highs are getting through with this radio shack transformer but I think it's somewhere passing below around 8k.  I can't stop playing with it...total blast.  I was up late last night reading the official urei docs on calibration and I'm definitely going to need to find someone with a scope to help me.  I don't know when I'm supposed to buy a scope...perhaps it is time.  The circuit appears to be in complete working order and I am no electrical engineer by any means.  I accidentally wired the release pot backward according to the front panels I've seen...but other than that it is in sound working order sans calibration/setup.

I intend on running two channels off of one 30VA 30+30 avel lindberg transformer.  VR1 seems warm but my 2N3053 seems quite hot even with the heatsink on it.

The 3 deck T600 mallory was easy to hook up after looking at the purple schematic (which conveniently has both the bridged T and non bridged displayed).  Unfortunately, the wiring of the bridged T is beyond my mental capacity at this point.  I responded to an old T600 thread on the drawing board but I think many folks are entirely sick of hearing about the T600.  I suppose I could just start guessing...but the bridged T was $75 and I'd rather not cover it in solder  :cry:

Anyway...thanks mnats!
Title: 1176LN Rev D DIY
Post by: Stagefright13 on March 29, 2007, 11:32:32 PM
There are some nice looking scope programs online for download. They use the soundcard for input. Dunno how good they are but I saw a cool looking dual trace one with free 14 day trial.  :wink:
  I am just starting to fully study this project right now. I have just about everything and the board is stuffed. I was side tracked for a while building some Eisen pres and the Drip LA2A.

  Off topic but I purchased some pres from Eisen and Jens suggested I check this board for Baumans 2*5*2*0* clones. So I did and was like HOLY CRAP these guys are building la2a's and 1176's, etc. here!! I was shocked lol! So I joined asap. Thought you all would get a snicker out of that...
Title: 1176LN Rev D DIY
Post by: kazper on March 30, 2007, 10:22:47 AM
I've been in contact with Cinimag regarding a input transformer and david Geren passed on this info regarding another o-12 alternative.

We have a new transformer (only 3 in stock, though) which will do the O-12 job with saturation level more similar to it.  This new transformer is the CMMI-2PCA. Its impedance in 37.5/150:600.  Strap the primary in series and hook it up backwards for 2:1 step-down.

There under $45 each.
Title: 1176LN Rev D DIY
Post by: nerd on March 30, 2007, 11:13:38 AM
Quote
I've been in contact with Cinimag regarding a input transformer and david Geren passed on this info regarding another o-12 alternative.

We have a new transformer (only 3 in stock, though) which will do the O-12 job with saturation level more similar to it. This new transformer is the CMMI-2PCA. Its impedance in 37.5/150:600. Strap the primary in series and hook it up backwards for 2:1 step-down.

There under $45 each.


This could be really cool. Finding an o-12 has proven very problematic for me and I think the UTC alternatives (A20, A21) would lack the saturation charateristics of the o-12. Did he provide any more details? I already have an order with them, I would love to tack these onto it. Also... The price seems right.
Title: 1176LN Rev D DIY
Post by: ap123 on March 30, 2007, 01:38:07 PM
There's also the Altran C-3837-1 O-12 reproduction.  I'm not sure if Edandersen is acquiring those or not.  I'm planning on doing two group buys, one for PEC Bridged Ts and the other for Altran C-3837-1s.  The minimum qty is 30 on the PEC; not sure on the Altran I am contacting them today.  Again, there was some talk about edandersen getting them but I haven't heard anything else about it and assume it's no longer happening.
Title: 1176LN Rev D DIY
Post by: edanderson on March 30, 2007, 02:51:53 PM
i do have an order in for the altran input transformer.  mako is working on a new input transformer pcb to make all of the input transformer options a bit easier to use.  i think even the newly announced cmmi-2pca should drop right in to the pcb.

in any case, i should have some c-3837s in stock within two weeks if altran keeps to their delivery schedule.  bear in mind that i ordered them nearly five weeks ago.

ed
Title: 1176LN Rev D DIY
Post by: edanderson on March 30, 2007, 02:54:04 PM
as for the PEC attenuators, i was thinking about doing an order of those also, but not for another few weeks; too many irons in the fire.  if aaron wants to order them and take care of it, he should go for it.

ed
Title: 1176LN Rev D DIY
Post by: ap123 on March 30, 2007, 05:48:34 PM
Cool.  

Reserve your PEC Bridged T (http://www.groupdiy.com/index.php?topic=21817) on the black market.  I was just going to wing it and order 30 but I figured this might help those who aren't on the forum all day with a chance to get in on these.

Aaron
Title: 1176LN Rev D DIY
Post by: BladeSG on March 30, 2007, 09:56:56 PM
Hi all... quick question.

I'm having a little trouble finding ceramic caps in 200pF (C3,C6). If I use 220pF is that going to cause problems? (I'm thinking it shouldn't matter)

Thanks in advance

P.S. If anyone has any 2N3391 transistors spare that you'd like to sell me, pls PM.

Steve
Title: 1176LN Rev D DIY
Post by: Lowfreq on March 30, 2007, 10:33:05 PM
I just paralleled two 100pf caps.
Title: 1176LN Rev D DIY
Post by: mnats on March 31, 2007, 06:57:10 PM
As Ed mentioned earlier I have been working on an input transformer PCB. Since most of the modern input transformer options seem to be PCB mount I wanted to provide a tidy way of nailing them down without resorting to vero/perf board. The boards will accept the following transformers:

Altran C-3837-1 - O-12 clone
CMMI-2PCA - Cinemag's substitute for the O-12
CMLI-15/15B[PC] - as used in some of the reissues
Lundahl LL1540 - for a G1176 style input but wired 2:1 stepdown
OEP A262A2C - wired reversed for 2:1 stepdown

(http://www.geocities.com/m_natsume/images/1176_rev_d_trx2_small.gif)

There is an option on the boards for an H-Pad as used on some of the reissues described by W O'B (http://www.groupdiy.com/index.php?topic=212586#212586) and neatly drawn by ed (http://www.groupdiy.com/index.php?topic=245590#245590). This might provide a low-cost alternative for those unable to get a T attenuator.

Of course, you can also use a T attenuator at the input or use a potentiometer following the transformer ala G1176.

I'll post the files for a home etch, but will also have a batch made that can be distributed with the Altran transformers that ed is going to offer.
Title: 1176LN Rev D DIY
Post by: kazper on March 31, 2007, 09:31:38 PM
Hopefully Ed gets a few more than he went with on the Cinimags. I would definitely like 2 units with the altrans.
Title: 1176LN Rev D DIY
Post by: ap123 on March 31, 2007, 10:34:33 PM
Quote from: "kazper"
Hopefully Ed gets a few more than he went with on the Cinimags. I would definitely like 2 units with the altrans.


Same here.  I'm wondering if I might be able to bump up the quantity on this round of production.  $25.75/unit at 25 pieces.
Title: 1176LN Rev D DIY
Post by: BladeSG on April 01, 2007, 01:18:24 AM
Quote from: "Lowfreq"
I just paralleled two 100pf caps.


Thanks. :thumb:
 
That's probably what I'll end up doing too.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 01, 2007, 12:24:56 PM
Here's a couple pics:

(http://www.stagefrightonline.com/1176_1.JPG)
(http://www.stagefrightonline.com/1176_2.JPG)

  WOW! that little black board seems to have an attitude just sitting there doesn't it? Too bad we can't make cases out of transparent aluminum ala Star Trek...
  Gonna fire mine up later this week. I went to radio shack to look for some knobs for another project. And saw that $3.99 1:1 transformer that Aaron used to test his so I broke the budget and procured it.
  I would like to thank Mnats for all his hard work. That input tranny board looks great. Also like to thank Ed and Aaron for helping all of us get the parts we need! And special thanks to Kato and his parts list for those of us that are new to the Mouser and Digikey catalog. Altho I am getting better with those bible things now. This project has turned into a great team effort. Looking forward to that uneasy feeling of hitting the power button lol...
  Speaking of power... What size fuse do ya think I should use?

John
Title: 1176LN Rev D DIY
Post by: BladeSG on April 02, 2007, 03:05:38 AM
Quote from: "BladeSG"
Hi all... quick question.

I'm having a little trouble finding ceramic caps in 200pF (C3,C6). If I use 220pF is that going to cause problems? (I'm thinking it shouldn't matter)

Thanks in advance

P.S. If anyone has any 2N3391 transistors spare that you'd like to sell me, pls PM.

Steve


It only occured to me today that a 220pF cap is only +10%.... duh!!
Title: 1176LN Rev D DIY
Post by: ap123 on April 02, 2007, 02:57:35 PM
Just a note... Leeds Radio in NYC just got a shipment of NOS Mallory T600s (probably off ebay, doh!).  The price is $36+shipping.  Not sure how many they have.  

You can order by telephone (718 963-1764) , fax, (718 963-1963) or email sales a/t leedsradio d/o/t com.

Note to moderator: I didn't want to post this on the black market as I'm not the seller.
Title: 1176LN Rev D DIY
Post by: kazper on April 02, 2007, 07:49:34 PM
What is the deal with the R-OPT1 Threshold Pot on the threshold board?

I searched around and must have overlooked it....  anyone have any clues on if we should put like a 2K pot there and adjusted it to read zero... for later..?

Kevin
Title: 1176LN Rev D DIY
Post by: ap123 on April 03, 2007, 03:59:23 AM
Quote from: "kazper"
What is the deal with the R-OPT1 Threshold Pot on the threshold board?

I searched around and must have overlooked it....  anyone have any clues on if we should put like a 2K pot there and adjusted it to read zero... for later..?

Kevin


I probably have little place even taking a stab at this; but I believe it is an optional pot that allows you to tweak the threshold that is otherwise dependent on the ratio.  If you look at page 10 of the urei manual (pdf page 13...ugh) there is a chart titled "1176LN Transfer Characteristics."  It also says:

Code: [Select]
The transfer characteristic graph also indicates the region of the threshold.  Signals at levels below the threshold will not be affected by the compression/limiting action.  Higher signal levels will cause a controlled decrease in amplifier gain resulting in a change of dynamic range.  The 1176LN input level control adjusts the amount of signal to be processed above the threshold, and hence the degree of compression or limiting.

I cannot determine to what degree you could adjust the threshold and with what pot...but I would be very interested in some hints  :grin:  I would also be curious to see what the nuke/all-in setting looks like on the transfer characteristic graph.
Title: 1176LN Rev D DIY
Post by: mnats on April 03, 2007, 08:27:38 AM
Quote from: "kazper"
What is the deal with the R-OPT1 Threshold Pot on the threshold board?

First raised by Jakob in the big 1176 help thread (http://www.groupdiy.com/index.php?topic=201766#201766) as a response to some people saying that the threshold on their G1176 was too low. Turn the board over - you have to cut the trace indicated in order to use it. Leave the trace alone and the board works just like a regular G1176 rotary ratio board as is.

I think that by chasing a higher threshold you run the risk of putting too hot a signal through the FET, thus increasing distortion, but I thought others might want to experiment.
Title: 1176LN Rev D DIY
Post by: Skylar on April 04, 2007, 01:19:19 PM
mnats,

...couple of questions:

Will your pushbutton boards work with the Rev D project?  
If so, will the wiring need to be done differently from your other 1176 projects?
Details are not absolutely necessary, I can figure it out when I get the boards ...just looking for a clear and distinct "yes" or "no".

Thanks
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 04, 2007, 11:05:35 PM
I'm up to the pushbutton thing myself. I have the original style latching type. I am looking into it now. I haven't built the G1176 so haven't done this before. After looking at the schematic I can't tell which switch is which. Like top to bottom etc. I guess I can find the info eventually unless someone has a link they can post.
  On another note I did power up my board and ps is looking good did voltage check and all and after 2 hour warm up.  
  30-0-30 toroid 34ac in, 44 after rectifier, 29.7 after reg. Running normal temps. R87 is a little hot but is about norm I believe. Prolly 160 degrees F ? Didn't hook anything else up yet tho... Waiting on pot from Aaron for last part :) (Besides input tranny)
  I do have to make 4 small aluminum parts on milling machine to hold pushbuttons to the case studs tho. Guess I'll do that Friday. Then figure how to wire them this weekend.
  But it passed the smoke test!!! Woohoo!!
   :green:
Title: 1176LN Rev D DIY
Post by: Skylar on April 06, 2007, 01:42:20 PM
Okay, I just octuple-cross-referenced...

mnats' pushbutton layout
mnats' wiring guide
mnats' Rev D schematic/layout
mnats' Rev F layout
Urei Rev D/E schem
Urei Rev K schem (on which gyraf's G1176 is based)
Gyraf's G1176 layout
Purple MC76 schem

Looks like mnats' pushbutton boards will work fine for his Rev D boards, though you might want to follow the schematic closely during the build.
Title: 1176LN Rev D DIY
Post by: usekgb on April 06, 2007, 07:05:29 PM
Quote from: "ap123"
Quote from: "kazper"
Hopefully Ed gets a few more than he went with on the Cinimags. I would definitely like 2 units with the altrans.


Same here.  I'm wondering if I might be able to bump up the quantity on this round of production.  $25.75/unit at 25 pieces.


I'd sure be in for a couple of these as well.  

Cheers,
Zach
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 06, 2007, 11:53:57 PM
I'm doing the pushbuttons p2p. I got the GR one done. Took a while because of all the jumper wires etc. The Purple schematic was a great help. Should be testing it tomorrow with tha "Greenbud" lol.
  Only problem is Fedex sent my output pot to the front desk at a hotel. But they say they will get it to me tomorrow... We shall see! And free shipping.  :green:
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2007, 12:16:28 AM
Mines up and running. No gain reduction tho. Probably something to do with the bypass. Will fix it tomorrow. No noise or hum tho. Had to uses 3 schematics to get the wiring right. The purple schematic was much better when wiring the GR push switches because it say what button is what. Then used the urie schematic to get meter wiring,
  Would be nice to have it all in one...
Title: 1176LN Rev D DIY
Post by: sintech on April 08, 2007, 07:25:50 AM
Stagefright13, this maybe helpful as a reference point.

I pulled an original Urei 1176 apart and copied out the point to point for interconnects, meter and ratio switch banks. This was for the Purple MC76 so some PCB pads may be labled differently.

Purusha redrew the switchbank, and is much clearer in this format.

(http://tat-purusha.net/diy/P2P-MC76.jpg)

(http://i44.photobucket.com/albums/f23/sin-tech/2MeterSwitchBank2.jpg)

(http://i44.photobucket.com/albums/f23/sin-tech/1MeterSwitchBank1.jpg)
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2007, 10:29:18 AM
WOW thank you! Can't go wrong with that. :) Appreciate the help. It's very close right now and sounds fine except some kind of wiring problem. I will check it against that diagram.

btw I used a .022 cap on the pot...

Thanks again,
John
Title: 1176LN Rev D DIY
Post by: timmygrimm on April 08, 2007, 11:44:42 AM
forgive the rather basic question, but i'm wondering if this power transformer will work for a dual rev d.

Digi-Key Part Number     TE62065-ND
Manufacturer Part Number    62065
Manufacturer    AMVECO MAGNETICS
Description    TRANSFRMR 22V 1.136A WITH WIRES


thanks!

tim
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2007, 12:02:22 PM
I used the 30-0-30 (60 ct) 1.3 amp one from digikey.

In that drawing shouldn't the 10 meg resistor be wired on the 20:1 side?

OOPS the toroid I used was from mouser. Hammond    546-182K30
that's the part number.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2007, 12:54:23 PM
Hey Sintech thanks! Got it working already! I was missing one wire to pad 7. A very important one lol. Just need to finish a few odds and ends and bolt her into the rack, :) After calibration that is...
  That 10 meg resistor is on the 20:1 side of the switch according to the schematic.

Thanks again,
John
Title: 1176LN Rev D DIY
Post by: sintech on April 08, 2007, 01:03:54 PM
Congrats :-)

The 10 meg is a buffer for all buttons in, it's as Urei wired it on a 70's 1176LN.
Title: 1176LN Rev D DIY
Post by: Skylar on April 08, 2007, 02:53:05 PM
sintech,

Awesome diagram--this will surely help!  Thanks.


Regarding the 10M resistor:
I've noticed that the placement of this component varies widely from schematic to schematic.

Where is the best place to have this resistor?


Check it out:

(http://i73.photobucket.com/albums/i222/skylargray/1176/1176_TenMeg.jpg)
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2007, 05:21:31 PM
Mine seems to work fine at the mnats position. BTW here are some pics

(http://www.stagefrightonline.com/11761)
(http://www.stagefrightonline.com/11762)
(http://www.stagefrightonline.com/1176tranny)
It works and sound great even with the radio shack tranny. :)
My meter pegs easy in +4 and +8 tho. Long before 0 vu in protools.
This project was alot of fun! Thanks for all the help once again.
Now for that input tranny  :green:

John
Title: 1176LN Rev D DIY
Post by: ap123 on April 09, 2007, 03:19:38 AM
Quote from: "Stagefright13"

http://www.stagefrightonline.com/1176tranny


:razz: Ha...awesome.
Title: 1176LN Rev D DIY
Post by: edanderson on April 09, 2007, 07:53:03 AM
Quote from: "Skylar"
sintech,
Regarding the 10M resistor:
I've noticed that the placement of this component varies widely from schematic to schematic.

Where is the best place to have this resistor?


if you look carefully, you can see that regardless of how it is drawn, electrically there are only three choices:

no resistor at all - (urei rev D)
from the junction of r63 and r64 (aka wiring point 20) to the sidechain rectifier (aka wiring point 21) - (urei rev E, purple mc76/77, mnats rev D)
from the junction of r87 and r42 to the sidechain rectifier - (urei rev f-k)

and really the difference between the last two is very minor when you consider the combined resistance of r42, r43, r44 vs the 10M resistance of r46.  you don't want to leave the connection to the sidechain floating when all the switches are open, so r46 should be there, but putting it in either place will stop any crazyness from happening.

ed
Title: 1176LN Rev D DIY
Post by: mnats on April 14, 2007, 07:57:00 AM
(http://www.geocities.com/m_natsume/images/1176_rev_d_.5_01_small.jpg) (http://www.geocities.com/m_natsume/images/1176_rev_d_.5_01.jpg)
Click for big.

Got half of my 1U stereo version running. The bakelite version of the UTC Ouncer is in there temporarily. The Cinemag output transformer had to shed its end bells to fit.

In order to fit all the controls on the front panel I had to do some juggling. Far left is a Clarostat bridged T-pad. There's a DPDT toggle to select GR or Output metering for the Sifam AL19. Pull the Attack knob to turn off the Gain Reduction. And the Alpha 5 position switch is hard wired with the divider resistors for ratio selection with Slam for the fifth click.

Sounds very sweet. How's everyone else's build going?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 15, 2007, 04:27:46 AM
Mine works perfectly. It has also passed at least a 30 hour burn in. The output transistor runs hot. But I have seen alot of older gear have burn marks on the circuit boards from normal use. (After many years) Usually resistors tho. I should measure it's temp to see if it is in spec for that part.
  I can't use mine in the studio yet tho cause I only have the 1:1 radio shack input transformer. Waiting to hopefully get one from Edanderson when they arrive. The frequency response is not so great as you can imagine.
  I still have to doctor a couple things... Like the VU lamp I have is the Sifam 12 volt. I used 2 100 ohm power resistors in series to drop the voltage. (200 ohm) but I still have 12.9 at the lamp so I have to order a few extra values. But I am close. I have 34 volts AC from power tranny.
  And I learned a lot on this project!  Thanks again for making it available.    
 
 :thumb:

Also if you are using Kato's BOM and are using pushbutton switches you will need 1 extra resistor. You'll need a 8.2k 1/4 watt (R77)
Title: 1176LN Rev D DIY
Post by: ap123 on April 17, 2007, 04:16:38 AM
Upon actually following the calibration procedures outlined in the urei docs I encountered a never-ending circle of confusion.  For instance, the more I tinker I realize that the procedure outlined in 5.3.2 is sort of dependent on that of 5.3.3 and so on.

Does the procedure to adjust the null and tracking require the complete removal of R44?  On page 60 of the urei pdf, there is a document entitled "Meter Calibration" the relationship between R75, R71, and R44...that is a sensitive dynamic that one there, especially when you throw the R44 as a trim pot into the mix.

Also, I read in the G thread that shorting terminal 22 to ground is the same as placing attack in the off position (as mentioned numerous times in the docs).  Does this apply to the rev D board?

Can the bias adjustment be made with the meter trim pots whacked out (or centered, say)?  

I need to finish reading the rev G thread one of these days...sorry.
Title: 1176LN Rev D DIY
Post by: BladeSG on April 17, 2007, 04:27:08 AM
From mnats site:

Quote
Leave R44 - the Tracking Adjust trim pot - off the board until you have calibrated the meter circuit according to the 1176LN manual from the JBL Pro Service site


http://www.geocities.com/m_natsume/1176_revision_d
Title: 1176LN Rev D DIY
Post by: nerd on April 17, 2007, 10:15:03 AM
Quote
MNATS: How's everyone else's build going?


Its getting there. I am playing the waiting game.

Some of my transistors didn't meet the hfe spec so I am waiting on some new ones.

I didn't realize matching FETs was going to be a big deal for a stereo unit, so I am waiting for a batch of FETs too.

Waiting on the input attenuator from a group buy. Thanks ap123.

Waiting on my cinemag output transformer order. They seems a little absent minded with regards to small orders.

I tried to cut corners on a few things and they didn't work out, i.e. meters and a power transformer, so I just got that straightened out.

My only concern now is the input transformers.
Title: Lorlins on parts list
Post by: kato on April 17, 2007, 11:46:17 AM
Someone (thank you) pointed out to me that the Lorlins on my parts list have solder eyelets rather than PCB pins. I'm sorry, I have no idea how I did that.

I updated my parts list. (I still have not ordered the Lorlins; current part is still not verified.)

Reportedly, you can cut the eyelets off and insert the pins into the PCB but bending is required.

Anyone know of a part that fits more accurately, please let me know.
Title: 1176LN Rev D DIY
Post by: ap123 on April 17, 2007, 02:22:55 PM
I think I have something in wrong.  I built two boards and both behave the same; when I send 1khz as instructed in the calibration instructions and turn the bias cw until 1dB drop, when I change ratio something is wrong.  There is no limiting or sometimes there is, sometimes not; intermittent only with the change of the ratio switch.  Before I tried calibrating I had it working on a few of the ratio settings.  Also, even after being powered on for 15 minutes my output level will climb with the test tone; very slowly.  Makes the bias adjustment odd.  I really think I have something together wrong.

Dumb question yeah yeah... but is the actual limiting behavior/functionality of the 1176LN dependent on the calibration of the meter circuit?  That is probably the question of the month for me.

BladeSG, thanks...it had been so long since I had actually read the mnats rev d page that I prematurely soldered in R44 so I guess I'll be removing that.
Title: 1176LN Rev D DIY
Post by: Skylar on April 17, 2007, 03:11:58 PM
Sorry to interrupt, ap123, but...

Is anyone currently trying to get a hold of Cinemag CM-96731 output
transformers?  I was thinking of buying direct, but if someone has an
order pending, I would like to get in on that as opposed to ordering
a single transformer from Cinemag.

Anybody?
Title: 1176LN Rev D DIY
Post by: nerd on April 17, 2007, 03:34:38 PM
Quote
Is anyone currently trying to get a hold of Cinemag CM-96731 output transformers?


I kept missing the boat on group orders so I ordered 2 direct from them. Did the whole thing with email and paypal. They were cool and didn't give me the "blow off" becuase it was a small order. I did have to remind them a couple of times though. I have not recieved it yet, but it has not been that long since I ordered. I believe they just whipped up a batch so they may have still have some around.
Title: Re: Lorlins on parts list
Post by: usekgb on April 17, 2007, 03:46:33 PM
Quote from: "kato"
Someone (thank you) pointed out to me that the Lorlins on my parts list have solder eyelets rather than PCB pins. I'm sorry, I have no idea how I did that.

I updated my parts list. (I still have not ordered the Lorlins; current part is still not verified.)

Reportedly, you can cut the eyelets off and insert the pins into the PCB but bending is required.

Anyone know of a part that fits more accurately, please let me know.


The Lorlins do fit if you cut the eyelets off.  You do have to bend the tabs out a little bit though.  I have one question regarding these though.  The PCB for the switch that has 4 pins in the center is clearly marked as to the direction that the switch is mounted.  The other PCB, however, has no markings for mounting orientation.  Can anyone clue me in to this?

Cheers,
Zach
Title: Re: Lorlins on parts list
Post by: kato on April 17, 2007, 05:24:21 PM
Quote from: "usekgb"

Can anyone clue me in to this?


Maybe you can decipher this image from Mnats wiring page:

(http://www.geocities.com/m_natsume/images/1176_rotary_wiring_meter_ratio_overview.jpg)

Quote from: "usekgb"

You do have to bend the tabs out a little bit though.


That doesn't sound too bad. Thanks for the input.
Title: Re: Lorlins on parts list
Post by: ap123 on April 17, 2007, 05:30:52 PM
Quote from: "usekgb"
The other PCB, however, has no markings for mounting orientation.  Can anyone clue me in to this?

Cheers,
Zach


I too was a bit confused by this.  One board has the "A" pin identified but the other does not.  I assumed that because the alignment wasn't noted that it didn't matter.  Those are the kind of stupid assumptions I make on an hourly basis, though.

I just cut the tabs off and bent them out a little...that worked excellently.
Title: Re: Lorlins on parts list
Post by: usekgb on April 17, 2007, 05:49:41 PM
Quote from: kato
Quote from: "usekgb"

Can anyone clue me in to this?


Maybe you can decipher this image from Mnats wiring page:

(http://www.geocities.com/m_natsume/images/1176_rotary_wiring_meter_ratio_overview.jpg)

I'm just a little confused on this Lorlin 2pole 6pos switch.  It appears to have 4 more contacts along the outside ring, and it can me mounted two different ways.  Would it matter if I get the "A" and "C" contacts reversed, or will it still work just fine?

Cheers,
Zach
Title: Re: Lorlins on parts list
Post by: ap123 on April 17, 2007, 05:58:52 PM
Quote from: "usekgb"

I'm just a little confused on this Lorlin 2pole 6pos switch.  It appears to have 4 more contacts along the outside ring, and it can me mounted two different ways.  Would it matter if I get the "A" and "C" contacts reversed, or will it still work just fine?

Cheers,
Zach


I'm very interested to know this...perhaps that's why I can't bias this thing to save my life.  Maybe my ratio switches are backwards.  That'll be fun to take out...  :?
Title: Re: Lorlins on parts list
Post by: usekgb on April 17, 2007, 06:18:14 PM
Quote
I'm very interested to know this...perhaps that's why I can't bias this thing to save my life.  Maybe my ratio switches are backwards.  That'll be fun to take out...  :?


That's exactly why I want to find this out before soldering.  And what a nightmare to remove these once soldered!

Cheers,
Zach
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 18, 2007, 04:12:10 PM
I would just use a continuity checker on the switch and check it verses the schematic to confirm the orientation. Then you'll know for sure.
Title: 1176LN Rev D DIY
Post by: ap123 on April 18, 2007, 04:33:39 PM
Stagefright13, did you finish calibration on yours?  I'd be interested to know any of your comments on calibration.  I still get no limiting on certain positions of the ratio switch all dependent on the bias adjustment.  I just can't seem to get it to work once I follow the bias procedure.  I'm going to check the switch continuity when I get home.  Inside the switch is two half moons and I believe they cannot be oriented incorrectly...but it's time I test that because, like I said before, I simply cannot calibrate the unit.  It also seems like the function of the limiter is dependent on the meter calibration itself -- and I've read some say "zero the meter before you bias" but the bias effects the meter zero.  I'm going to go back to where I should've left out R44 and start from there.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 18, 2007, 05:01:00 PM
I did the first 2 steps of calibration then just adjusted the other pots to get the meter to work ok at -10 and -3 gain reduction for now. I still have to install an input transformer and a step down resistor for the meter lamp. So I figure i'll remove r44 at that point and finish it all at once. With a more precise calibration. I rather calibrate it in it's final configuration.
  But it works fine at all GR settings and output settings. And confirmed audibly. It actually sounds surprisingly good "as is" on some stuff.

Plus it's always nice to burn something in a while first...
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 21, 2007, 11:25:09 AM
Just turn the q bias all the way up past the point where the meter climbs... Then set your zero at +1. Then turn bias down till your meter reads 0. You should do this with an external meter. But I did mine with the internal one for now.

Are ya having any luck yet?

John
Title: 1176LN Rev D DIY
Post by: ap123 on April 23, 2007, 01:03:42 AM
After reading some other 1176 threads I grounded input to the chassis and two things happened: 1) the noise disappeared and 2) all aspects of the unit became much more stable.  Now I've done the calibration and the world makes sense again.  Between my germanium and this I sound a lot more talented than I actually am and that is a mission I will never escape  :grin:  I have one channel done but I'm waiting on the PECs to ship to finish my second....surely my hakko will enjoy the break.

I pulled R44 out of both my boards and decided to pop in a socket for my feeble mind's sake.  I simply bought a 6 pin socket and snipped it in half.  This way I can pull R44 out if I need to mess with the meter section again (without killing the pads).  This has ended up being a bit of a classroom in a box for me...so sockets are good.
Title: 1176LN Rev D DIY
Post by: nerd on April 26, 2007, 09:59:43 AM
Any word on the Altrans?

I picked up some cool tamuras that should work ok but I will still like to get the 'real deal', well... almost 'real deal'.
Title: 1176LN Rev D DIY
Post by: edanderson on April 26, 2007, 01:28:22 PM
Quote from: "nerd"
Any word on the Altrans?


Quote from: "Skylar"
Is anyone currently trying to get a hold of Cinemag CM-96731 output transformers?


i should have a page up with both the altran input and the cinemag output for sale next week sometime.  they will not be limited to 1 per person this time.  i am waiting for mnats input transformer pcb to arrive so that everyone who buys an input transformer can get a pcb also.

ed
Title: 1176LN Rev D DIY
Post by: okgb on April 26, 2007, 02:01:42 PM
Perfect Ed , thanks

 i can already tell you i'll need one output & two in's ,
but i'll wait , great idea to add the in boards

regards Greg
Title: 1176LN Rev D DIY
Post by: kazper on April 26, 2007, 05:01:12 PM
good deal..

I'm down for two inputs for sure.
Title: 1176LN Rev D DIY
Post by: usekgb on April 26, 2007, 06:42:23 PM
I'm interested in two input and two output.

Cheers,
Zach
Title: 1176LN Rev D DIY
Post by: Skylar on April 26, 2007, 06:46:41 PM
Thanks for offering this Ed!  I'll definitely be grabbing an in & out.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 26, 2007, 08:54:18 PM
Wow that's great news! Thanks once again for helping everyone Edanderson! Most of this stuff would be impossible without this board and a team effort. And the people like Ed and Mnats that make things like this possible. I hope I can contribute as much in the future. I am however new to the board but have some things to offer I hope.

 :grin:
Title: 1176LN Rev D DIY
Post by: edanderson on April 27, 2007, 10:40:20 AM
hey everybody.  i'm glad to be helping out as best i can.  i know it can be hard to get ahold of obscure transformers in one or two piece qtys.

so that we don't clutter up this thread, please don't reply here with how many of what that you want.  and please don't PM me or email me.  i'm not taking reservations -- there should be plenty for everyone.  the order page will be up next week.

ed
Title: 1176LN Rev D DIY
Post by: mnats on April 28, 2007, 07:12:18 AM
(http://www.geocities.com/m_natsume/images/1176_rev_d_xformer_board_small.jpg) (http://www.geocities.com/m_natsume/images/1176_rev_d_xformer_board.jpg)
Click to enlarge

As mentioned previously (http://www.groupdiy.com/index.php?topic=257987#257987), I have had some transformer boards made up for this project.
These will fit the Altran O-12 clone that will soon be offered by Ed. Ed will be providing boards with each input transformer.
(http://www.geocities.com/m_natsume/images/1176_rev_d_xformer_board_altran.jpg)
They will also fit the following transformers:

CMMI-2PCA - Cinemag's version of the O-12
CMLI-15/15B[PC] - as used in some of the UA reissues
Lundahl LL1540 - for a G1176-style input but wired 2:1 stepdown
OEP A262A2C - wired reversed for 2:1 stepdown

Other transformers that use a standard pinout could also possibly be adapted to use this board.

(http://www.geocities.com/m_natsume/images/1176_rev_d_xformer_board_oep.jpg)

The Lundahl and OEP will work with the board as-is. The Altran and Cinemags require wire links configured to adapt to each unique pin assignment. Pads are just under the transformer footprint and a guide is printed on the screen layer of the board. You can use short pieces of tinned bare wire under the board or insulated wire through the holes.

There are footprints for constructing an H-pad described by W O'B (http://www.groupdiy.com/index.php?topic=212586#212586) and used on some of the UA reissues. Use this option if you are not using a T-Pad.

Self-etch files have been posted on my Rev D page (http://www.geocities.com/m_natsume/1176_revision_d.html).

I will also post information on how to get just the board soon.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 02, 2007, 11:41:11 PM
AP123 great Idea with the dip socket! I just fixed my R44 the same way. The trimmer fits in nice and snug. Highly recommended. It's a real pain to flip the board to calibrate. This solves the problem easily.

For the record I ended up using a 220 ohm 5 watt resistor to fire the 12 volt lamp from 34 volts ac. Final voltage 11.78.

Thanks for sharing!

John
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 03, 2007, 11:45:13 PM
I finally did a full calibration on mine tonight. However I have 1 issue. I did qbias again no problem this time with my external bomb factory meter in pro tools. Then did gain reduction meter tracking purple style. Got both 0 VU on meter and 0 volts (touchy) across R74. Then it says to reinstall R44 wich I did and I get a 3 DB drop almost on the GR meter. Even with R44 set at 1.8 ohms. (The lowest it will go)

It seems everything works perfectly and my meter is accurate finally. In gain reduction and actual output level. Until I install R44. I am ready to omit R44 altogether. My unit is perfectly stable and accurate without it. Or am I missing something?
Title: 1176LN Rev D DIY
Post by: ap123 on May 04, 2007, 01:20:53 AM
I had the same exact issue with R44.  Curious to hear about this one.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 04, 2007, 04:17:09 PM
Well it could very well be that using a 1:1 input transformer could be the problem... I will redo it when I get the new transformer. The 1k tone is actually going in alot hotter than the typical 2:1 transformer would do. Just a thought.

One reason I wasn't gonna do a full on calibration without the correct and final parts installed.

But I have been having alot of fun playing with mine today just the same...
 :green:

John
Title: 1176LN Rev D DIY
Post by: ap123 on May 04, 2007, 09:53:29 PM
I have the R44 issue with a UTC O-12, too. (eh em...yes, I was dumb enough to buy an O-12 for one billion us dollars)
Title: 1176LN Rev D DIY
Post by: tommypiper on May 05, 2007, 09:19:43 PM
I'm building 2 channels in one box.  Looking closely at the power supply options.

Option1:
Onboard PSU, run two boards supplied by one torroid power transformer.  What transformer ratings would we need?  

There's no regulation on the -10v onboard supply.  I don't quite understand how this works.  Is it a complete supply as is?

Option 2:  
It might be better to use one of the little outboard PSU to supply two channels, instead of the onboard supply.

If so, how do we build it to get +30v and -10v?  Isn't that over-stressing the regulators by forcing such widely different voltage supplies?  Wouldn't we need like a higher voltage transformer?

Isn't there a potential for crosstalk if the regulation feeds two channels?  Is the supply adequate for two channels?  

The size of the caps are double on the onboard.  So, I'm wondering how can we run TWO channels with half the reservoir cap values (outboard) as ONE channel onboard PSU?  That's essentially 1/4 the value per channel.

Is anyone else using the outboard PSU?  I've seen no posts on it.  I've looked everywhere, does anyone have a schematic for the outboard PSU?

:guinness:
Title: 1176LN Rev D DIY
Post by: edanderson on May 06, 2007, 05:13:40 PM
input and output transformers now sold out.

ed
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 06, 2007, 07:27:32 PM
Wow Mnats thanks for the free board! I think I owe you a beer! And Ed too!  :grin:

As far as the external PSU I believe Mnats mentions it can supply up to 1.5 amps. And the board only uses 40 milliamp. I am going on memory here so correct me if I am wrong. I'm gonna build my external one as a lab supply for goofing around...

If ya check the purple schematic they spec a pretty small transformer. I personally used a 60 centertap. 1.3 amp but that is WAY overkill even for 2 boards.

And I did check my onboard ps when I first fired it up and had +30 and -10 volts where appropriate. I think r81 82 drop the voltage

John
Title: 1176LN Rev D DIY
Post by: tommypiper on May 06, 2007, 11:20:04 PM
Thanks, John.  The Purple shows 23VA.

Do you have any info or a schematic for the external PSU?  

I'm not sure how to get the wide range of voltage.

cheers, :guinness:
Title: 1176LN Rev D DIY
Post by: ap123 on May 07, 2007, 05:29:32 AM
Quote from: "tommypiper"
The Purple shows 23VA.


http://www.groupdiy.com/index.php?topic=22073&highlight=y236106

I have an avel lindberg Y236107 (30va 30+30) running two independently regulated rev d boards.  This seems kind of hokey to me...but I built one rev d and decided to build a second a couple weeks later.  I might convert my 2-1176 to use it as soon as someone tells me what I've done (two psu on one transformer) is a bad idea.  There is an option to use trim pots for the adj legs of the regulators.  The -10 is regulated by the 337 (http://www.national.com/pf/LM/LM337.html).
Title: 1176LN Rev D DIY
Post by: tommypiper on May 07, 2007, 11:20:59 AM
Thanks.  Glad to hear you can run two boards off one transformer.

Yes, I know the regulator will control the -10v on the outboard PSU.  But I think controlling it from 30v AC from the transformer to -10v DC is over stressing it.

I believe a resistor is needed somewhere to get the voltage closer.  Does anyone have a schematic for the outboard PSU?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 07, 2007, 05:19:26 PM
Here's a quote from Mnat's docs:

"The power supply is taken from a later revision. It uses a three-terminal regulator for the +30V 50mA rail rather than a hard-to-get power zener. The negative supply is unchanged."

Sorry no schematic here for the external one.

As for the external PS board all the values are on the board except R1 and R2 wich are step down resistors to drive leds. You would have to calculate them any way depending on output voltage... And also VR1,2 and R3,5. R3 and 5 would be the fixed values for the adjustable regulators to supply the required voltage. And VR1 and 2 would be used if ya wanted a variable supply. Don't know those values off hand but you should be able to look them up.

As far as going from -34 volts ~ after rectification with a 30-0-30 transformer to -10 volts... I'm not sure. Also the -10 supply may use very little power. But I don't know this for sure. Maybe someone more experienced with this could chime in.

John
Title: 1176LN Rev D DIY
Post by: tommypiper on May 07, 2007, 10:10:30 PM
Quote from: "Stagefright13"

As for the external PS board all the values are on the board except R1 and R2 wich are step down resistors to drive leds. You would have to calculate them any way depending on output voltage... And also VR1,2 and R3,5. R3 and 5 would be the fixed values for the adjustable regulators to supply the required voltage. And VR1 and 2 would be used if ya wanted a variable supply. Don't know those values off hand but you should be able to look them up.

As far as going from -34 volts ~ after rectification with a 30-0-30 transformer to -10 volts... I'm not sure. Also the -10 supply may use very little power. But I don't know this for sure. Maybe someone more experienced with this could chime in.

John


Thanks, John.  Yeah, I see the part info on the boards. But I don't really understand how it works or how to figure out what value resistors to put in there.  I've read other posts in my searches  that say  you can't use the LM3x7 regulators to move the voltage more than a very small amount, so I'm wondering why, how this can work to create +30 and -10 at the same time.   :? The resistors must set the voltage to a close range, then the regulators do the rest.  How do we figure out these resistor values?  
Is it me, or is it strange that we have these boards but there's no information.  And no one seems to be using them.  Why do they have LEDs, for example?  Is that part of the circuit function, or is that for our front panels?
Title: 1176LN Rev D DIY
Post by: nerd on May 07, 2007, 11:15:06 PM
I am doing a dual using the Avel Lindberg Y236106 (30VA 25 + 25). I built up the Mnats "Little PSU" as described on his site using the variable resistors to set the voltages. It seems to work fine (PSU only, I am not done putting the whole 1176 thing together yet).

The Neg regulator gets warm, but I put a double sized heat sink on it. I think it will be fine.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 07, 2007, 11:33:07 PM
The external psu is for building a supply for 2-1176 or for experimenting. I  built a single and works great. But I am very happy to have the extra boards to experiment with! And I will when I have some money for another transformer. :)

Building a 2-1176 is a bigger project in my opinion. And may require a bit more knowhow and money. I personally wouldn't try a stereo unit without at least building a single first. The biggest fun for me is learning new stuff.

I think I remember in the 80's Radio Shack had those Engineering handbooks or whatever they called them. With circuit snippets including the LM series voltage regulators with schematic examples. And lots of other stuff. Wonder if they still sell them? Hint?

But now I guess the internet has that stuff...

John
Title: 1176LN Rev D DIY
Post by: nerd on May 08, 2007, 08:03:00 AM
About the Little PSU: In case I wasn't clear, it works fine at +30, -10.


As for building the dual - This is my first DIY in many years and certainly the biggest DIY I've tackled. I've come across issues building the dual, but probably not what you would think. Aside from the usual FET matching, which was no big deal actually, the biggest problem I am having is jamming all the stuff in one case, trying to find two of everything (o-12s, attenuators), getting knobs that fit and look right with the pre-made case I purchased.

Of course, I am not finished yet, so I am bound to run into a few more things, but I don't anticipate anything major.
Title: 1176LN Rev D DIY
Post by: mnats on May 08, 2007, 08:44:03 AM
Quote from: "tommypiper"
Is it me, or is it strange that we have these boards but there's no information.

I don't possess any special knowledge about electronics and would never consider myself a "designer". That's why my outboard power supply is based on an off-the-shelf adjustable regulator.
Quote from: "tommypiper"
I've looked everywhere, does anyone have a schematic for the outboard PSU?

I have to ask - but have you looked at the data sheet for the LM317/337? Aside from a few 1N400xes to protect against input and output shorts and the initial full-wave rectification and filtering, the PSU is based on the same schematic in the data sheets. That's why I have never bothered to draw it out. If someone would like to redraw it and host it somewhere, please feel free.
Quote from: "tommypiper"
How do we figure out these resistor values?

As you will see, I'm no artist either. Here is the basic schematic of the regulator circuit sketched out on the back of an envelope:
(http://www.geocities.com/m_natsume/images/adjustable_regulator.gif)
Looking at the data sheet, the typical reference voltage of the regulator is 1.25V. The adjustment pin current is typically 50uA. Calculating the current through the 120 ohm resistor: 1.25V/120R=10.41mA. Add the current from the adjustment pin: 10.41mA+50uA=10.46mA. That's the current that will flow through the bottom resistor.

Calculate the resistor for the desired voltage and round the figure to the nearest available value. Let's say you need 30 volts: 30-1.25/10.46mA=2749 ohms. Use a 2.7k resistor.

Or use the values posted on my draft PSU page (http://www.geocities.com/m_natsume/psu.html). Or just put a trim pot in place of the fixed resistor and dial in the voltage you need.

Hopefully I don't get busted by the real electronics people on the forum, but I think the above is correct.

Quote from: "tommypiper"
There's no regulation on the -10v onboard supply. I don't quite understand how this works.

There is regulation of the onboard -10 supply. Try doing a search for "zener regulator".
Title: 1176LN Rev D DIY
Post by: okgb on May 08, 2007, 08:50:38 AM
Sometimes the searches are not always that easy BUT gotta appreciate
having a board as nice as your's  and gaining a little more electronics
knowledge won't hurt us as we figure it out.

 The sreening i really appreciate , and of course the Black is too cool too

thanks for everything so far  [ haven't got mine together yet so i'll be back ! ]

regards Greg
Title: 1176LN Rev D DIY
Post by: mnats on May 08, 2007, 09:02:12 AM
Quote from: "okgb"
Sometimes the searches are not always that easy

I agree with you. But you reminded me of something I wanted to add: don't limit yourself to searches of this forum.

BTW, fixed some of the mathematics above...
Title: 1176LN Rev D DIY
Post by: tommypiper on May 08, 2007, 11:07:18 AM
Quote from: "mnats"

Or use the values posted on my draft PSU page (http://www.geocities.com/m_natsume/psu.html).


Ah!  So this is what people have been referring to.  I've been searching and could not find that.  (That page is linked only from the Gyraf 1176 clone page, BTW, not the Rev D, so if you only read the rev D you won't find it).  

EDIT: OK, I've found some better datasheets that cleared this up and actually I was able to look at the indentations on the little PSU card to follow the traces and figure out what you had included and not included from the various set-up options.   That made things clearer.  For example, you are using the diode protection, but not the bypass cap (which is not needed because the 1000 uF are close by).

I actually had forgetten zener regulation, thanks for pointing it out.  I feel like a dolt.  

Is there a concern about cross talk with single supply off board regulation for two channel boards?  

Which is better, running two boards from the little PSU?  Or  the onboard supplies fed by one toroid?

Cheers.
Title: 1176LN Rev D DIY
Post by: ap123 on May 08, 2007, 12:43:41 PM
I linked to the LM337 datasheet in my previous post but it wasn't that obvious enough a link.  I had a feeling I could find one of these and I did...it's a voltage divider calculator made for the LM317 and 337:
http://spazioinwind.libero.it/andreabinello/lm317-lm337/index.html
Title: 1176LN Rev D DIY
Post by: tommypiper on May 09, 2007, 10:14:36 PM
Edited: redundant
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 14, 2007, 07:01:55 PM
Finally done WOHOO! Sounds awesome. Here's a pic:



(http://www.stagefrightonline.com/1176finish)


Thanks Mnats and ED!!   :green:  :thumb:  :thumb:
Title: 1176LN Rev D DIY
Post by: dissonantstring on May 14, 2007, 08:42:38 PM
hey stagefright,
nice and clean build! :thumb:
i'm just starting mine so i'm jealous!  :green:
whats that honkin' resistor coming off of the AC input to the main board?
-grant
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 14, 2007, 09:10:25 PM
A 5 watt 220 ohm to drive the Sifam 12 volt  meter lamp. And thanks. I'm warming it up for final calibration now. :)
Title: 1176LN Rev D DIY
Post by: kato on May 15, 2007, 06:33:25 AM
Looks great!

What kind of enclosure is that?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 15, 2007, 08:42:02 PM
It's yet another Tat Purusha case. His cases are really nice. And it is not dirty or anything. My camera makes white flakes and specs in macro mode. It's kinda old... Or maybe I should clean the lens?

It sounds REALLY sweet. Gonna use it on my next session friday doing electric guitar and vocals. And yes it does make stuff sound cool even with the gain reduction off lol.

Calibration was no problem after I went to the bottom half of the jbl manual. (to the page Mnats has on his monitor in the pic on page 1 of this thread.)

John

Thanks once again for the parts list Kato, helped alot. I like having all real nice parts in her.  :thumb:  :thumb:
Title: 1176LN Rev D DIY
Post by: gevermil on May 16, 2007, 09:20:57 PM
How are folks mounting the UTC 0-12 ?
I have some adm line amps that Im planning to use and they have 0-12s but attached to the pcb . Im going to try to use the cases but they are backward  
So I gotta think of something

http://i133.photobucket.com/albums/q47/gevermil/IMGA0514.jpg

http://i133.photobucket.com/albums/q47/gevermil/IMGA0516.jpg
Title: interlocking switches
Post by: codered on May 23, 2007, 09:45:48 PM
Folks this question is for those who are using the pushbutton switches instead of the rotary switches:

Does anybody know where I can order the ITT switches used in the reissues.They are the interlocking type & I remember reading about someone using them in the builds(not rev d).Does anybody know if Purple would sell a couple?
thanks
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 27, 2007, 05:23:09 PM
Holy crap this sounds great! Doing a session right now. Has a full up front sound. Killer on vocals! Thanks so much everyone.

Using an Eisen 512 copy into it and then 002r at 96khz. Gotta go but this thing rules!

Now I know why Andrew at Purple is worshiped for his 1176. Wish I had one of them 2.

Cya

John
Title: 1176LN Rev D DIY
Post by: Bri on May 27, 2007, 11:35:29 PM
Great to hear the good news, John!
Congratulations. :sam: :sam:

BTW, what did you do about R44?
Did you just leave it out, or did everything finally work out in the end.

--Brian
Title: 1176LN Rev D DIY
Post by: Sleeper on May 29, 2007, 01:03:55 PM
Quote from: "ap123"
Quote from: "tommypiper"
The Purple shows 23VA.


http://www.groupdiy.com/index.php?topic=22073&highlight=y236106

I have an avel lindberg Y236107 (30va 30+30) running two independently regulated rev d boards.  This seems kind of hokey to me...but I built one rev d and decided to build a second a couple weeks later.  I might convert my 2-1176 to use it as soon as someone tells me what I've done (two psu on one transformer) is a bad idea.  There is an option to use trim pots for the adj legs of the regulators.  The -10 is regulated by the 337 (http://www.national.com/pf/LM/LM337.html).


Hi ap... I have the same setup exactly.  I wouldn't waste the time to rebuild it. if you look at the JLM power station, for example, you basically have 5 power supplies on one transformer. at the very least you have a couple of bridge rectifiers and whatever else comes after.
I'ts maybe easier to screw up your grounding, but thats about it.
Kelly
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 29, 2007, 04:15:23 PM
I set r44 for 1k then stuck it back in and readjusted accordingly. So all trimmers are accounted for :)

John
Title: 1176LN Rev D DIY
Post by: sleepingtiger on June 05, 2007, 12:46:52 AM
I'm confused. I'm building a couple of single channel units and using the onboard power supplies and Avel Lindberg torroid's that are 30VA, 30-0-30. After building up the supplies on both boards I'm getting -9.75 and +24.5. Upon troubleshooting I realize that both Mnats and Kato's parts lists and the Mnats schematic call for a +24v regulator (I'm using the Fairchild regulator linked from Kato's list). To me, this explains why my + voltage is low but I'm reading through this thread and noticing that others are getting a correct voltage. Are you guys using adjustable regulators? Is this an oversight on the partslists and the schematic? Is there something that I'm missing here? Should I actually be seeing +30 with the regulators I'm currently using?
Title: 1176LN Rev D DIY
Post by: mnats on June 05, 2007, 08:26:26 AM
Quote from: "sleepingtiger"
I'm confused...After building up the supplies on both boards I'm getting -9.75 and +24.5. Upon troubleshooting I realize that both Mnats and Kato's parts lists and the Mnats schematic call for a +24v regulator (I'm using the Fairchild regulator linked from Kato's list). To me, this explains why my + voltage is low but I'm reading through this thread and noticing that others are getting a correct voltage...Is there something that I'm missing here?

Take a look at this schematic fragment (drawn right to left like the original power supply schematic):
(http://www.geocities.com/m_natsume/images/1176_30V_PS.gif)
The common or ground connection of the 7824 regulator does not connect to the ground directly, but sits between a voltage divider composed of R87 and R89. The regulator dutifully puts out 24 volts across R87, but as the ratio between the top and bottom resistor is 80%/20%, the remaining voltage goes across the bottom resistor.

I'm sure someone else can explain it better, but yes - you should get 30V from this arrangement. If not, there is something wrong. Check the usual things, covered many times in the big 1176 thread and elsewhere...
Title: 1176LN Rev D DIY
Post by: sleepingtiger on June 07, 2007, 02:31:32 PM
Thanks Mako, I appreciate your reply.

It was a dumb mistake on my part. I was trying to use some resistors I had lying around and on the package "22OHMS" looked a lot like "220Ohms", so I had 22 ohm resistors in there. The embarassing but funny thing about it is that I even measured them before I placed them in there. I suppose this shows that sometimes I see what I want to see rather than seeing what's really there...

Okay, another question for Mako or anyone who might know. On one of the boards, when desoldering the regulator to get to the resistor in question I lifted the two outside solder pads on the components side of the board. Have I ruined this board? The pads on the other side are intact so I could solder the regulator back in place but I don't know if losing the top pads will cause a short. I don't know enough about reading the diagrams of the pcb to figure this out.

Thanks again!
Title: 1176LN Rev D DIY
Post by: josh on June 07, 2007, 03:07:03 PM
Quote from: "sleepingtiger"

Okay, another question for Mako or anyone who might know. On one of the boards, when desoldering the regulator to get to the resistor in question I lifted the two outside solder pads on the components side of the board. Have I ruined this board? The pads on the other side are intact so I could solder the regulator back in place but I don't know if losing the top pads will cause a short. I don't know enough about reading the diagrams of the pcb to figure this out.
Thanks again!


I've done that many times and jumpering a wire to the next position on down the trace usually works just fine.
Title: 1176LN Rev D DIY
Post by: dissonantstring on June 07, 2007, 03:09:01 PM
hi sleeping tiger,
if you indeed only lifted the top pads for the +v-reg. then you are o.k. because they do not connect to anything.  if you reference mnats top layer (ground plane side) image in his DIY Rev.D document you will see that they do not connect to anything.  ohm out the pads to the traces connected to the v-reg. legs on the trace side to make sure that they are still o.k.

BTW, i just finished soldering all my components to my Rev.D board and ran a test.  no smoke, but the 7824 gets pretty hot even with a heatsink (i'll probably add a larger one or possibly run leads and mount it to the chassis).
also the 2N3053 gets screaming hot.  i bought a larger heatsink for it as well, but i'm wondering how normal this is?  i've read a few posts about them running hot, but this seems like the life of these components will be significantly shortened running this way.  

cheers,
grant
Title: 1176LN Rev D DIY
Post by: wmb on June 07, 2007, 04:47:17 PM
I'm about to start stuffing these boards over the weekend and I have a question. Is there any particular order compnonent-wise that I should follow? I've not built anything from the qround up that used as many transistors. Usually I have always dealt with them last but it looks like it could get tight in a few places.

I usually start with the smallest components and work my way up to the larger ones. This generally means resistors, caps, transistors, connectors, pots, transformers, case in that order.

It there any reason I should wait and install any board components as a final step?

Cheers, Wm.
Title: 1176LN Rev D DIY
Post by: mnats on June 07, 2007, 05:41:32 PM
Grant - looking at the data sheet the operating temperature of the 2N3053 is -65 - 200°C. With the heatsink that I used (the one on Kato's list, I believe) I measured 50°C after the unit had been on for an hour or so.

If you fooled around in the days of germanium the idea of 200°C is scary, but at my job we rework SMDs at 300°C+ and still have functioning boards!
Quote from: "wmb"
It there any reason I should wait and install any board components as a final step?

Only if you want to calibrate your meter circuit. Have you read the Rev D page?
Title: 1176LN Rev D DIY
Post by: dissonantstring on June 07, 2007, 06:06:35 PM
Quote from: "mnats"
Grant - looking at the data sheet the operating temperature of the 2N3053 is -65 - 200°C. With the heatsink that I used (the one on Kato's list, I believe) I measured 50°C after the unit had been on for an hour or so.

thanks that gives me a baseline to measure the temp on the 2N3053 and i do need a better heatsink.  i did see that they are rated up to 200°C, but i get nervous sometimes.  thanks for the confirmation.

Quote from: "mnats"
If you fooled around in the days of germanium the idea of 200°C is scary, but at my job we rework SMDs at 300°C+ and still have functioning boards!


+300°C!  :shock:

thanks for the info mako, much appreciated! :thumb:
Title: 1176LN Rev D DIY
Post by: sleepingtiger on June 07, 2007, 06:35:31 PM
Thanks, disonantstring (and everyone else). That's what I thought that I was seeing but I wasn't confident that I was perceiving correctly. I checked continuity and it looks like everything is in order...
Title: 1176LN Rev D DIY
Post by: wmb on June 07, 2007, 10:37:54 PM
Quote from: "mnats"

Quote from: "wmb"
It there any reason I should wait and install any board components as a final step?

Only if you want to calibrate your meter circuit. Have you read the Rev D page?


Yeah, I have read the rev D page. Mentally I was excepting those components. I was mostly wondering if I should hold off on the transistors so they don't get damaged or something. Looks like I can just start building it.

Cheers, Wm.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on June 08, 2007, 05:34:26 PM
Yeah WMB just build her up  :thumb:

Just watch the voltage regulator and 3053 bend easily just looking at them the wrong way. LOL So handle the board carefully when installing it and all. And GL is a great diy project!

P.S. And don't forget to test all the transistors and match the required ones.

John
Title: 1176LN Rev D DIY
Post by: Stagefright13 on June 08, 2007, 08:49:32 PM
Other tips would be keep R87 off the board a bit so it has better cooling underneath. And bend the pins of the voltage regulator slightly forward. (Away from C25) So your heatsink doesn't touch C25. And put the screw in from the back of the heatsink. So the actual threads face forward. Away from C25. And is always good to use a thin coating of heat sink paste or Artic Silver when mounting heatsinks. And cut a 6 pin dip socket like Aaron suggested to mount R44 trimmer. It just makes it so easy to calibrate. Umm all I can think of...

And the heatsink for the 3053 that Kato has listed seems to work fine. It may feel hot but is WAY under spec as noted earlier. Have Fun!

John
Title: 1176LN Rev D DIY
Post by: Lowfreq on June 09, 2007, 12:59:10 AM
Ok chaps,  

I've nearly finished my RevD, but having a weee problem thats baffling me a bit. :?

The problem is that when i turn up the output pot (say a little more than a third of the way up) i get some nasty oscillation going on. The whole unit goes into some crazy static................. :shock: It works and sounds great with a low ouput.

So i did some basic (note very basic :roll: ) signal tracing with one of those home jobby things from Mark Burnley on the diyfactory page http://www.diyfactory.com/data/mbsignaltracing.htm, and when I got up to the drain of Q1, I was getting some strange noises coming through my test speakers. I checked Q11 to compare and that had good signal coming out of its drain leg.

I replaced Q1, and checked all the surrounding components but still had the same issue.

I think I'm looking in the wrong place???? Does this sound more like an issue with my 3053??? Maybe I've damaged a leg when i was trying to squeeze the heatsink on....... I'll buy a new one tomorrow and try.....

The weird thing is that when i use my signal tracer the oscillation dissapears....................... :shock: and i can turn the output up.
Actually if you touch some of the pads on the board with a wire thats not even connected to anything it stops the oscillation.............but starts to pick up radio at high gain............ is it a capacitance thing??

The gain control section seems to work ok, and i can really get this thing to pump. The problem still happens in bypass mode, so I'm thinking all is good in the gain control area.

I have used 2N5088 instead of 2N3707 in the the signal amp, and I've swapped the legs around, so I'm not sure if that would be the problem.......

Anyway, as you can see, I'm confused, and I've been going over this board all day...........................................................
so please any suggestions would be great. Just guide me in the general direction, and I'll get to it.  :green:
Title: 1176LN Rev D DIY
Post by: wmb on June 09, 2007, 02:18:40 AM
Thanks for all the great tips. I printed them out and added them to my collection of notes I've taken from the Rev D page and this thread.

I abbreviate all the time in my private emails but rather ironically can never figure out the ones others use in emails to me. This line included...
Quote from: "Stagefright13"
... And GL is a great diy project!



Cheers, Wm
Title: 1176LN Rev D DIY
Post by: Stagefright13 on June 10, 2007, 07:35:06 PM
GL = Good Luck   :)
Title: 1176LN Rev D DIY
Post by: mnats on June 10, 2007, 08:28:16 PM
Quote from: "Lowfreq"

The problem is that when i turn up the output pot (say a little more than a third of the way up) i get some nasty oscillation going on. The whole unit goes into some crazy static................. :shock: It works and sounds great with a low ouput.

I'm no good at this distance troubleshooting unlike Jakob and others but I'll try to help. It seems as though there might be feedback happening between the Signal Preamp and Signal Line Amp. You could confirm that the Line Amp is OK by disconnecting the output pot at pad 15 and feeding an unbalanced signal directly into the pot between the wire you removed and ground. Crank up the pot and see if you can get it all the way up without oscillation. If not, then you have isolated the problem to the Line Amp.

I seem to remember having a similar problem when I first hooked up the Cinemag output transformer to my prototype board. The problem seems to have been the lack of shielding (no cabinet) and/or poor grounding. Tell or show us how you've done your grounding. How is the main board grounded? Have you used shielded cable where the audio leaves/returns to the board?
Title: 1176LN Rev D DIY
Post by: Lowfreq on June 11, 2007, 08:13:52 AM
Thanks Mako,

Ok, I think I've located the issue. My wire (solid strand cat5) from star ground to the ground pad on the main board, had snapped close to the board (maybe from being moved around), but the outer wrapping was still intact.(Talk about decieving....... no wonder I couldn't see a fault :twisted:  )  
I've replaced the wire and the oscillation has vanished!! :green:  :thumb:  :thumb:  :green:

Quote from: "Mnats"
Tell or show us how you've done your grounding
Ok I'll try my best to describe things, in case there is a better way or I'm not quite doing it right.
I have one earth point near the IEC connected to the chassi, and from there I have star ground to pin 1 on the xlr input, pin 1 on the xlr output and to the ground pad on the main compressor board. And that's it.
Just like the picture. If I'm missing anything let me know.
(http://stephensheath.com/revdgrounding.JPG)

While I'm here I'll double check to see if I'm wiring up my t-pad correctly too. After looking at the pruple schem, I did this............
(http://stephensheath.com/Tpadcheck.JPG)

Quote from: "Mnats"
Have you used shielded cable where the audio leaves/returns to the board?
Yep, I kinda cross referenced to your G1176 instrusctions on sheilded cables and did the same wth the revD.

Anyway, I'm off to bed, and then tomorrow It's time to calibrate this sucker. :green:  :thumb:  :thumb:  :green:

Thanks again for the help!!! :sam:  :sam:
Title: 1176LN Rev D DIY
Post by: gevermil on June 11, 2007, 12:24:05 PM
How wild , just  having the same problem  :wink:
im  working to find the cause
heres some pics

http://i133.photobucket.com/albums/q47/gevermil/667.jpg
http://i133.photobucket.com/albums/q47/gevermil/IMGA0534.jpg
http://i133.photobucket.com/albums/q47/gevermil/IMGA0535.jpg
Title: 1176LN Rev D DIY
Post by: kazper on June 11, 2007, 01:24:38 PM
Quote
My wire (solid strand cat5)


You would be allot better off using some 24-28 gauge multi-stranded wire. for this.
Title: 1176LN Rev D DIY
Post by: JdJ on June 12, 2007, 11:19:24 PM
Hey Lowfreq-

What T pad are you using?  I'm wondering what the proper way to wire it is myself.

Cheers,

Josh
Title: 1176LN Rev D DIY
Post by: kazper on June 13, 2007, 12:58:29 AM
JdJ which one do you have?

I have 2 types  of the NOS ones that have been floating around. I actually have 4-600 T-pads with 2 Omeg's on the way.

I'll try and remember my photo web hosting and figure this out and post some pics of how to hook up the ones I have access to.
Title: 1176LN Rev D DIY
Post by: Lowfreq on June 13, 2007, 03:22:47 AM
Josh, I'm using the PEC from the group buy organised by ap123 a while back.

http://www.groupdiy.com/index.php?topic=21817&highlight=
Title: 1176LN Rev D DIY
Post by: mnats on June 13, 2007, 08:00:55 AM
Quote from: "Lowfreq"
Ok I'll try my best to describe things, in case there is a better way or I'm not quite doing it right.
I have one earth point near the IEC connected to the chassi, and from there I have star ground to pin 1 on the xlr input, pin 1 on the xlr output and to the ground pad on the main compressor board. And that's it.
Just like the picture. If I'm missing anything let me know.

This page says it better than I ever could:

http://rane.com/note151.html

Quote from: "Lowfreq"
While I'm here I'll double check to see if I'm wiring up my t-pad correctly too. After looking at the pruple schem, I did this............
(http://stephensheath.com/Tpadcheck.JPG)


Look at the schematic again. Notice there is a common wire between the source and load side of the bridged T attenuator? See that the two resistors connect to one end of the pot, not the wiper? Fix it and show us how you did it.
Title: 1176LN Rev D DIY
Post by: JdJ on June 13, 2007, 11:12:15 AM
I came across this (http://www.groupdiy.com/forum/posting.php?mode=quote&p=149159&sid=e39860991caba6cbcdc0bb79cb0971d0) the other day-

Quote from: "edanderson"
1. if that meter is a real VU meter, you should be able to use it without any additional circuitry.  try hooking the two terminals up to any line level audio source, and see if the meter moves as you would expect.  if so, it will probably work, and you can connect it as shown in the MC76 schematic.  if it doesn't work, then yes, you may need to make an external rectifier, using some diodes and a piece of perf board.  you don't NEED a meter for the compressor to work, however it is useful sometimes.

2. yes, input xlr to t-pad to o-12 pins 1 and 5.  if you use the attenuator we supply (the three deck black clarostat modpot), then use this diagram i stole from newyorkdave (thanks!):

(http://electronicdave.myhosting.net/miscimages/T600.GIF)

connect the input xlr hot (pin 2) to the "IN" and input xlr cold (pin 3) to "COM."  connect the "OUT" to pin 1 of the O-12 and the "COM" to pin 5 of the O-12.  the input xlr ground (pin 1) should connect to the cable shield on the way to the attenuator.  connect it to the shield of the cable going from the attenuator to the O-12, and dont connect the other end of that shield.  connect the xlr ground (pin 1) to the chassis ground.

ed


I'm using the 3 deck T's from Purple.

-Josh
Title: 1176LN Rev D DIY
Post by: nerd on June 13, 2007, 07:46:39 PM
I've got my PEC wired like this...

(http://www.hostpic.biz/uploads/a91e71ade7.gif)

I have not tested it though.
Title: 1176LN Rev D DIY
Post by: mnats on June 14, 2007, 03:32:10 AM
I had faith Lowfreq could figure it out for himself. Oh well, back to painting by numbers...
Title: 1176LN Rev D DIY
Post by: gevermil on June 14, 2007, 03:58:06 PM
Hey Mnat -
what voltages am I suppose to see off of the otuput transformer
My 2N3053 is smoking hot .
 :roll:
Title: 1176LN Rev D DIY
Post by: mnats on June 14, 2007, 04:54:15 PM
Quote from: "gevermil"
Hey Mnat -
what voltages am I suppose to see off of the otuput transformer
My 2N3053 is smoking hot .
 :roll:

"Off" the output transformer? Do you mean from the output? Zero DC volts.

If you look at the schematic there's 30 volts across the black wire (on the Cinemag) and ground and a small amount of DC across the White/Black and White/Red leads. I'm not sure if this will help you if your transistor is smoking though.

What is the actual temperature of your transistor while running? What sort of heat sink are you using? We discussed the operating temperature of the '3053 just on the previous page...
Title: 1176LN Rev D DIY
Post by: Stagefright13 on June 14, 2007, 08:37:16 PM
3053 transistor rated to 200 C

50 C is very hot bath water

100 C is boiling water.

As long as ya got a heat sink on it you are prolly ok.
Title: 1176LN Rev D DIY
Post by: gevermil on June 14, 2007, 08:39:39 PM
Thanks mnat , well -  I do see the voltages you speak of . My output pot  jumps to distortion very quickly so Im trying to find the source of that .
I just mentioned the transistor because I thought it was odd that I couldnt touch it  it was so hot .
Title: 1176LN Rev D DIY
Post by: gevermil on June 14, 2007, 08:47:32 PM
thanks stage , Its just a matter af figuring out the crazy output level .
As usual  with me its something stupid .
Title: 1176LN Rev D DIY
Post by: nerd on June 18, 2007, 09:58:33 AM
Regarding JdJ's post in the thread "Yawn...another 1176 (pics)"

Quote
I was curious about that too. I am trying to get 2 D's into Purusha's dual 1176 case and I'm thinking about stacking the boards. I suppose I'll just wire everything up and try moving around a bit to see what'll work. My case is 2 high, but a bit shallower than Mako's.


(http://www.hostpic.biz/uploads/3c8576b806.jpg)

(http://www.hostpic.biz/uploads/a6371300ad.jpg)

This is how I finally decided to do the two boards in a purusha case. It doesn't look that tight in the picture, but I spent hours trying to come up with a layout. Will noise be a problem? I don't know. I still have to find the time to finish wiring the thing up. My thought was to put the input transformers as far away from the power transformer as possible.

JDJ: How are you hooking up the bypass? I put a resistor in the R-OPT1 spot and hooked the switch up to where the wiper would be. I figured that since this is for threshold adjustment, I would basically be swithing the threshold in and out (so high that it doesn't do anything). I don't know if this thinking was correct.

Anyone: Also, and this is strange, one of the LEDs on my mnats little psu is blinking, but there does not appear to be any change in voltage on my meter. Any thoughts? If you exceed the operating range for an LED, but not enough to blow it up, would it do this?
Title: 1176LN Rev D DIY
Post by: JdJ on June 18, 2007, 02:57:02 PM
Quote from: "nerd"

JDJ: How are you hooking up the bypass? I put a resistor in the R-OPT1 spot and hooked the switch up to where the wiper would be. I figured that since this is for threshold adjustment, I would basically be swithing the threshold in and out (so high that it doesn't do anything). I don't know if this thinking was correct.


Nerd: check your PM.  Since there is a "bypass" position on the Meter board already (I believe it switches out the sidechain) I was going to do a hard bypass between the input/output jacks.  That way I can use it as a line amp for flavor (meter switch bypass), or hard bypass to check between compressed and uncompressed signals.

-Josh
Title: 1176LN Rev D DIY
Post by: nerd on June 18, 2007, 04:11:11 PM
Quote
Since there is a "bypass" position on the Meter board already (I believe it switches out the sidechain) I was going to do a hard bypass between the input/output jacks.


Damn! I am an idiot. I just went back and re-read the Purusha case thread. Early on someone says that the bypass bypasses the meter only, then later on someone counters that saying that it does turn gain reduction off. So, the other bypass is for a hard bypass, direct xlr in to xlr out.
Title: ???
Post by: shabtek on June 19, 2007, 12:13:56 AM
how is that 600 ohm t-pad working out?? isn't that a pretty heavy load for modern gear...I've got the altran input and a 4 pole switch to build the attenuator and I'm wondering if 600 is going to be useful if somebody plugs in the output of an 002...

any suggestions?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on June 19, 2007, 06:03:57 PM
I am using the Mallory 600 ohm T-Pad and works perfectly as a send (Out Then Back In) With my 002r. Although I use it for tracking mostly I have run lots of other tracks thru it with the 002 out.
Title: 1176LN Rev D DIY
Post by: Bri on June 28, 2007, 12:22:35 AM
Been trying to calibrate GR tracking for the past few days.

Before I replace the fets(spent hours testing and matching), I wondered if anyone had any other ideas:

Unit is compressing.

Triple checked the wiring.

Meter seems to be okay...reads -4db running a .775VAC signal through it.

Following guidelines on Gyraf's site for GR tracking, I adjust the needle for the 6db of reduction, I remove input signal, and needle moves about 2db back toward 0, I'll zero the needle, apply input signal again and the needle only moves to -1db, so I adjust down to -6db again...and this process goes on and on without change in characteristic until my "0 Set" trimmer(R71) cannot be adjusted anymore(full CW).

All my fets were matched to within 4%

My ratio switch seems to be functioning backward.
I get the most gain reduction when it's switched fully counter-clockwise.

I had my ratio switch set for 6 positions for a while, before I realized it.
Strange things were happening when I switched to position five and six.
The compression level would drop and then slowly ramp back up...took about 6 seconds.

I had the unit running for about five minutes without the main board grounded.

For awhile, I had a piece of cardboard under the main board instead of standoffs...perhaps the fets didn't like this?

Well, any thoughts would be appreciated.

--Brian
Title: 1176LN Rev D DIY
Post by: dissonantstring on June 28, 2007, 12:48:34 PM
hi brian,
if you are using a lorlin-type enclosed rotary you might want to try removing the stop pin from it and turning the switch until it reaches it full CCW position (essentially the first position) then put back the stop pin to stop at 5 positions.  you can do a search, i believe others here have had similar problems with the switch being off and jakob suggested it IIRC.  this basically resets your switch so that position 1 is really position 1.  not sure if this is the solution, but it at least will let you know if your switch is the problem.
regards,
grant
Title: 1176LN Rev D DIY
Post by: Bri on June 28, 2007, 06:57:04 PM
Hi Grant.

Yeah, I verified the switch/pin positions...seems correct.
I have the Lorlin 2-pole 6-pos.
Others have said the switch orientation didn't matter.
So as an experiment, I did configure the switch in the other positions...such as using only the last four positions.
However, the same thing still occurs, a couple db more GR when turned CCW.

I'm more concerned about not being able to set the GR tracking at all.
However, these two issues may be related, huh.

Any more ideas?

--Brian
Title: 1176LN Rev D DIY
Post by: dissonantstring on June 28, 2007, 07:44:36 PM
hi brian,
o.k. going back to you first post about this problem:

Quote from: "Bri"

Meter seems to be okay...reads -4db running a .775VAC signal through it.


so this is after fet conductance calibration and in GR mode at 4:1 ratio?
so with no signal and in GR mode your meter is at 0dB and in +4 mode it rests at -20dB?

Quote
I had the unit running for about five minutes without the main board grounded.


if you're talking about the pad GND on the side of the board between pads 20 and 18 then do not worry about this.  i forgot myself and powered up my board for longer than 5 minutes - no issues, though i haven't calibrated it all the way yet due to me wanting to mount my FPE front panel before calibration.

Quote
For awhile, I had a piece of cardboard under the main board instead of standoffs...perhaps the fets didn't like this?


naw, as long as it wasn't shorting on the chassis or anything the fets wouldn't be harmed.

check mnats site for the link the the JBL website and download the 1176 manual.  the calibration procedure is on pg. 39-40.  try calibrating to that instead.  can't say that i can help much as i'm still quite a newb and have difficulties troubleshooting my own builds, but lets post away to see if anyone sees the problem.
regards,
grant
Title: 1176LN Rev D DIY
Post by: Bri on June 28, 2007, 09:37:42 PM
Yeah, I have those pages from the manual printed out...among others.
I've tried at least three different methods of GR tracking adjustment.

Yes, all after Fet adjustment (Q bias).

If I turn the meter switch to VU mode, and run a 1khz 0db(.775vac) signal into the unit, turn input control all the way down, and turn output control all the way up, I get a -4db reading on the unit's VU meter.
When I remove the input signal, yes, the meter drops to -20.

With meter switch to GR mode, with or without a signal, Meter reads 0VU...
Unless of course I turn up the input control...which it will show gain reduction.
However, with my skepticism about the ratio switch, I'm never sure if I'm at 1:4 or 1:20.
The meter does show a db or two more reduction when I turn the ratio switch all the way left....which I'm assuming shouldn't happen.
I assume 1:4 ratio should be the first stop of the switch...continuing on to 1:20(fully CW)....correct?

Thanks for the help....you're less of a newb than I. ;)

--Brian
Title: 1176LN Rev D DIY
Post by: Bri on June 28, 2007, 11:47:38 PM
Given that others have mentioned the ratio switch and it's affect on threshold, I guess I'm not too worried about the ratio switch just yet.

What I would like to know is, what would be the cause for the unsuccessful GR tracking adjustments.

--Brian
Title: 1176LN Rev D DIY
Post by: Bri on June 29, 2007, 03:49:05 AM
Guess I'll just swap the relevant transistors....and note any changes.

--Brian
Title: 1176LN Rev D DIY
Post by: mnats on June 29, 2007, 04:41:56 AM
Quote from: "Bri"
If I turn the meter switch to VU mode, and run a 1khz 0db(.775vac) signal into the unit, turn input control all the way down, and turn output control all the way up, I get a -4db reading on the unit's VU meter.
When I remove the input signal, yes, the meter drops to -20.

If what you have written is correct, the result shows something is very wrong. Have a look at the schematic and try to follow along.

Whatever the signal you are feeding into the input of the circuit, the first thing it should hit is the input attenuator. If you have the input control all the way down as you describe, there will be little signal getting through.

Now looking at the output circuit, the X and Y points from the output transformer feed the meter switch. When switched to the +4 (VU) mode you are reading the output of the Signal Line Amplifier.

With not much going in to the compressor there should be not much coming out, so the meter shouldn't even register. By actual measure on my unit using the input signal you specify, the input control full CCW and with the output control full CW, the reading is -26dB...off the bottom of the scale.

Fix this problem first because without a good idea of the actual output you won't be able to accurately know how much gain reduction you're getting - therefore you won't know what you are trying to set your GR Meter Driver to show!

Quote from: "Bri"
Given that others have mentioned the ratio switch and it's affect on threshold, I guess I'm not too worried about the ratio switch just yet.

What I would like to know is, what would be the cause for the unsuccessful GR tracking adjustments.

Even though there appears to be a problem with your ratio control, no, it does not necessarily mean that you would not be able to calibrate your GR Meter Driver circuit. After all, you say you are getting gain reduction. Once you know how much gain reduction is happening (with the VU meter on the output or +4 setting) the goal is to calibrate the GR Meter Driver circuit to reflect that reduction in gain.

A common misconception, I think, is that the calibration procedure affects the compression action of the 1176. In fact, once you do the Q Bias adjust procedure your 1176 is compressing the way it always will. The calibration of the GR Meter Driver circuit is only so your meter will show how much gain reduction is happening in a way that is easily readable for humans. The compressor itself could care less about how the meter circuit is calibrated.

For calibration instructions, stick with the manual from the JBL site. As I've said elsewhere there doesn't seem to be any way to write it clearer than the original manual. Remember that this isn't a G1176 circuit. Some of the trimmer designations are different between the Rev C/D/E circuits than the F/G based G1176 version.

By the way, have you first calibrated the discrete meter circuit as described on page 40 of the big manual download?
Title: 1176LN Rev D DIY
Post by: Bri on June 30, 2007, 05:56:52 PM
Hey thanks mnats.

Yeah, I've got all those pages printed out in front of me. :)
I do get confused at the point where it says to trimpot to zero with the attack all the way CCW.  
Because, this is our bypass mode correct?
My meter doesn't function in bypass mode...should it?

Been troubleshooting for quite awhile.
I thought maybe I had my t-pad wired incorrectly.
I've wired it a few different ways since....looking at the Purple schematic.
I'm still unsure how to verify it's correct.
When it seems to be wired correct, I still get the ".775vac coming through" problem, when input control is full down and output control is full up.

In fact that's what led me to believe I have it wired wrong since the "low wire" connecting to the t-pad seemed to be more or less a straight connection the the input transformer.  I figured that's why the .775vac comes through when input control is full CCW and output control full CW.

However, there is a peculiarity I've noticed.
When I'm turning the input control CW, and I get to a little past 3/4 of the way to fully CW, the signal starts to suddenly and dramatically attenuate from then on.
This happens in bypass mode...actually, it didn't matter which meter setting.
Is this indicative of something obvious?

--Brian
Title: input and output transformers sold out...
Post by: edanderson on June 30, 2007, 07:06:36 PM
PLEASE DO NOT PM ME

sold out

ed
Title: 1176LN Rev D DIY
Post by: Bri on July 02, 2007, 05:10:57 PM
I'm not sure if my t-pad is working properly.
These are the resistances from mine...the two deck, group buy PEC.
Can someone verify if these are correct.
I arbitrarily numbered the terminals.
(http://home.fuse.net/me2/TPadA.jpg)
     
Full CCW
1-2:  2ohms
2-3:  37K
1-3:  37K

4-5:  18.5K
5-6:  96K
4-6:  87K


Full CW:
1-2:  43K
2-3:  13.5K
1-3:  37K

4-5:  87K
5-6:  1.6ohms
4-6:  87K

Thanks.
--Brian
Title: 1176LN Rev D DIY
Post by: drpat on July 02, 2007, 07:05:29 PM
...
Title: 1176LN Rev D DIY
Post by: Bri on July 02, 2007, 10:58:33 PM
Thanks Patrick! Very useful info.

I'll have to turn the input down fully when calibrating.
On this clone, the GR bypass is done using the meter switch, which also bypasses the meter.

Quick question.
Is that 0dbu and then -10 dbfs?"
What would the equivalent of -10dbfs on your Pro Tools system be in dbu or dbv?

I'm still unsure about wiring the t-pad.
I checked resistance continually while turning from CCW to CW, and it has strange characteristics.
Steady going, then sudden big spike, then sudden big drop, then up steady again until fully CW, for example.
This test was done bare, not in circuit and no resistors.
Didn't know if this was characteristic of a t-pad...or if mine is was "irregular."

--Brian
Title: 1176LN Rev D DIY
Post by: Stagefright13 on July 03, 2007, 11:19:16 AM
Maybe your t-pad is a little scratchy? Is it an NOS? Try running the wiper up and down a bunch of times to get it cleaned up. Are you using an 0-12 input transformer or one of the clones? Mine was pretty finicky using a temporary 1:1 input tranny 'till I got the right one.
Title: 1176LN Rev D DIY
Post by: Bri on July 03, 2007, 02:45:39 PM
Hey John.

I'm using the group buy, PEC...along with a UTC-A20.
Should be cool...yes?

--Brian
Title: 1176LN Rev D DIY
Post by: drpat on July 04, 2007, 07:52:27 PM
...
Title: 1176LN Rev D DIY
Post by: Bri on July 04, 2007, 09:29:41 PM
Thanks Patrick.  :thumb:

I'm definitely getting too much out.

When sending a 1khz .775VAC signal into the unit, .002VAC is getting to the main board when input control is fully CCW, and output control is fully CCW.

This seems correct.

But when I turn the ouput control fully CW(input control still full CCW), it's turning into .775VAC....measured at the output XLR.

I don't know enough to determine how or why.....yet.

--Brian
Title: 1176LN Rev D DIY
Post by: wmb on July 12, 2007, 06:36:40 PM
I'm trying to find a power transformer for a 2x1176 setup. I've seen a few mentioned here but I'm only having limited luck. My only successful hit is a Hammond 546-182K30 which mouser has in stock. The $52 price seems kind of high. Can anyone suggest a more affordable alternative and where to get it or is that the going rate for a 30-0-30 toroid?

Thanks, wm.
Title: 1176LN Rev D DIY
Post by: kazper on July 12, 2007, 07:00:51 PM
http://www.avellindberg.com/

Price break is on 2 transformers so order at least 2....

35VA 30-0-30 was $23 in April
50VA 30-0-30 was $25 in April

That's the one price, can't remember what they were priced at 2.

I ordered 25-0-25 for mine seems to do ok without a load (1176 not finished) P/N: Y236106  Price was 2 for $17.85 Each

Check these guys out for all your mounting needs
http://www.toroid.com/mounting_hardware/mounting_hardware.htm

Kevin
Title: 1176LN Rev D DIY
Post by: wmb on July 13, 2007, 03:42:36 AM
Thanks for the suggestions! That price seems much more friendly.

How did you get in touch with Avel Lindberg? I sent them an email at the beginning of the week but haven't heard anything. I will give them through the weekend and try calling next week.

Cheers, wm.
Title: 1176LN Rev D DIY
Post by: dissonantstring on July 14, 2007, 11:38:01 AM
hi wmb,
just call avel-lindberg.  i've had good experiences with them and i usually just call my order in - no problem.

@kazper,
kevin, thanks for that lead on the mounting hardware!  i was searching for that very same thing last week and could not find someone who sold just the mounting disk!  you rock!

regards,
grant
Title: 1176LN Rev D DIY
Post by: Bri on July 18, 2007, 02:41:08 PM
So,
My GR tracking adjustments would not take, so to speak.
My problem was that the effect of the meter adjustments would never eventually change.

I was following the 1176 calibration procedures on pgs 39-40, from JBL.
I Set levels for -10db of gain reduction...no R44.
After I adjust R75 for -10, and then turn Gr mode off, needle moves back up to only -6VU.
I then would readjust R71 for  0VU on the meter.
I'd turn GR mode on, and needle moves left, only to -2VU.
So I readjust back down to -10VU, etc., etc.
This repeats many many times, without even the slightest change.
R71 is eventually fully CW, and I have to stop, of course.

Although fets and transistors were matched, I changed them out.
I verified all resistors, components, wiring, and meter.
I had normal voltages(relative to the data I could find).

After a couple weeks of troubleshooting this, last night, I decided to see what would change if I put R44 in.
I put R44 in and I was shocked to see the meter suddenly tracking almost perfect.
I repeated the calibration procedure with R44 in, making some minor adjustments, and now everything is fine.

Can someone explain why this is...or what it indicates.
I'm happy that everything is finally functioning, but I'd feel better knowing why.

Thanks,
Brian
Title: 1176LN Rev D DIY
Post by: mnats on July 18, 2007, 05:42:03 PM
Quote from: "Bri"
Can someone explain why this is...or what it indicates.
I'm happy that everything is finally functioning, but I'd feel better knowing why.

It seems to indicate that you did not follow the "Meter Calibration 1176 With Discrete Components in Meter Circuit" instructions before doing the gain reduction meter tracking adjustment  :wink:
Title: 1176LN Rev D DIY
Post by: Bri on July 18, 2007, 06:51:55 PM
Ah, I think I see.
Adjust for -10VU and 0VU just once, and then stick R44 back in.
And THEN the repetitive adjustments.

Well, the bright side to all that unnecessary troubleshooting is that I learned a lot more than I would have...that is for sure.

And I was really trying hard to avoid that infamous, humiliating, obvious oversight. :)

Thanks mnats...it's a great project.
If I could get a hold of another board and an output transformer I'd build another one ASAP.  :sam:  :guinness:

Cheers,
Brian
Title: 1176LN Rev D DIY
Post by: mnats on July 19, 2007, 03:57:56 AM
Quote from: "Bri"
Ah, I think I see.
Adjust for -10VU and 0VU just once, and then stick R44 back in.
And THEN the repetitive adjustments.

No. Why not just read the page I referred to? Its title is just what I wrote in the quotes.

In short, you want to:

1) Null the meter circuit itself first, then...

2) Calibrate the meter circuit to the compressor.

The former requires that you remove R44 and the latter requires that R44 is in circuit. Step 1 is listed as A and B in the page referenced. From there you can skip to one of the other calibration pages to do step 2 above.

As I've stated a few times now it can't be written much clearer than in the original manual. However, you must pay attention to the fact that most of the  instructions I've seen refer to later revisions of the 1176 and the trimmer designations are different. Where they refer to R54, this is R44 on my Rev D where I have substituted a trim pot instead of a fixed, selected resistor to make calibration easier. It's labeled "TRACKING ADJ", the name it is given in later revisions (F and on).
Title: 1176LN Rev D DIY
Post by: Bri on July 19, 2007, 12:41:50 PM
Hi mnats.

I was following the discreet meter adjustment page, actually.
I just got a little confused at part C.
I was trying to adjust tracking before I had put in R44.
And that of course was my embarrassing blunder.
It's clear now.

Cheers,
Brian
Title: 1176LN Rev D DIY
Post by: mnats on July 19, 2007, 05:15:28 PM
Quote from: "Bri"
Thank you for clearing that up.
I had become a bit confused, for the various reasons.

Me too. What you wrote above is essentially correct - R44 has to be installed before you can adjust the meter circuit to the rest of the compressor and you have to set the input control until the compressor shows a 10dB drop in gain.

But I want to make sure that everyone knows you have to set the meter circuit null before calibrating it to the compressor.
Title: 1176LN Rev D DIY
Post by: Bri on July 19, 2007, 05:25:53 PM
:thumb:

Aside from my troubles(being my first major DIY)...
the unit sounds awesome!

Thanks mants, and everyone else!

Now I gotta go and make it pretty.

Cheers,
Brian
Title: Meter tracking issues...
Post by: JdJ on July 24, 2007, 02:45:43 PM
Hey all-

Got my dual 1176 all tied up and it sounds great.  I am having a hard time properly calibrating it however.

I have followed the JBL/1176 manual instructions as closely as possible- let me review:

I started with R44 out of the circuit- set the Null and Zero Adjust so there is .00 volts across r74.

I then put R44 back into the circuit- followed the directions for Q bias.  (Interestingly, after I put R44 in- even with no signal the meter dropped to around -20 on the internal VU with no signal- however this was before I calibrated the meter to the compressor, so I forged ahead.)  The Q bias went with no problems.

Here's where things go awry-  I have cross referenced all of the revisions for resistor names and functions just so I could be sure I know what the directions are referring to (Meter Null Calibration and Meter Gain Reduction Calibration refer to different revisions in the 1176 instructions resistor wise...)

I get a 10db swing no problem switching from GR Bypass to GR, but when I set the Zero adjust to register 0 on the Meter with no input signal (I set this up with rotary style knobs), I can't get the R44 Tracking adjust to bring the needle above -20 with -10db reduction on my external meter?!  So I end up stuck here- right around step #20 on the JBL site instructions.

Other observations:

When I switch to GR Bypass mode I get nothing on the meter in any situation- ie no signal- lots o' signal- I'm not sure if this is normal, or if the  Meter should go back to 0...

When I switch the ratio switch, the needle swings quite a bit with no signal present...

I will say that other than the meter tracking, the unit sounds killer, and all other functions seem to be working properly.

Any help is most greatly appreciated!

Thanks,

Josh
Title: 1176LN Rev D DIY
Post by: Bri on July 24, 2007, 10:26:26 PM
Hi Josh.

Hopefully mnats or others will chime in here.
It's a bit more difficult for me to give you some good answers, because I don't know the circuit backwards and forwards.

However, what I can tell you is, yes, the meter needle will jump when switching ratios.

In GR bypass mode, the meter needle will be at rest...all the way to the left.

For the various reasons, without a lot of seemingly trivial detail, it's not always easy to get a truly accurate idea of another's procedures and methods...

So if this is the case don't mind me, however, you have to adjust for the -10db swing before you put R44 in circuit.
So take R44 out, readjust your "zero set and "null adjust" appropriately whilst getting the zero voltage across R74.
Then inject the .775vac 1khz tone, appropriately adjusting input and output controls for the 10db GR.
Then put R44 back in, and hopefully the meter will now properly adjust.


--Brian
Title: 1176LN Rev D DIY
Post by: Stagefright13 on July 24, 2007, 10:54:52 PM
You have to set the bias FIRST. Turn the trimmer up till the meter Stops climbing and a little more if ya want. And wait a few to make sure it is maxed. Then set the zero at +1 THEN turn the trimmer down to achieve 0VU (1db drop) And make sure it has been on half hour at least to warm up. And don't touch any transistors. I hear you can blow on them (Humid air) and effect their performance. But I may just be paranoid ;)

THEN go on to adjust for the other steps such as the 0 volts. Ya have to do it in order for it to work properly. I used the Urie document except I used a dimm on the resistor "Purple Doc style" cause I kinda got loopy at that point lol. Then went back to the Urie instructions.

Make sure your using the discrete components directions.

And set R44 for 1k before ya reinstall it cause it will be at least close at that point.
Title: 1176LN Rev D DIY
Post by: JdJ on July 25, 2007, 10:41:45 AM
So just to clarify:

1. Null adjust
2. Q bias
3. 10db swing
4. Then R44?

In the Urei/JBL cal instructions it refers to adjusting R54=R44 Tracking Adj on step 17 right after readjusting the meter to read 0 in step 15.  So before R44 goes back in- the meter will be at zero and there should still be 0 volts across R75 right?

Quote
Turn the trimmer up till the meter Stops climbing and a little more if ya want.


So this is what they mean by turning the Q Bias all the way counter clockwise, you are just going about it a different way, right?

Thanks for the responses!  This will be attempt #3.  It's a real PITA to desolder R44 when the boards are in the case...  :mad:

Cheers

 :guinness:

Josh
Title: 1176LN Rev D DIY
Post by: Bri on July 25, 2007, 02:56:52 PM
I hear ya.  I had to destroy my R44 to get it out.
I then put in a socket.

Well, in regards to the order,  it may not really matter whether you do the null or the Q-bias first, but I would take John's advice and do the Q-bias first.

I've seen a few different bias methods described, but yes, with a signal injected, you're essentially turning the bias trimmer(CCW?) until the fet is out of it's conductive range...voltage increases...turn until it stops increasing...and a bit beyond, so you're obviously sure.  
They are touchy/sensitive...so always adjust carefully.

I mostly used a couple DMMs to calibrate, so I didn't have to rely on the the unit's meter.
So now that the fet is out of it's conductive range, I still have my .775v signal coming in, and I readjusted the input and output controls to get a nice round 11db(2.7484v) coming out...measured with a DMM at the output XLR.  
Now, all ya have to do is carefully turn the bias trimmer CW(?) until you read a 1db drop...i.e, my output would now read a steady 10db(2.4495v).

Not to add more decision and confusion, but FWIW, I have seen info regarding the fact that biasing even further, say, 2db or more, may allow for a "smoother" compression given the nature of the fet within this particular circuit.

So now you're set to do the rest of the calibration.

And yes, before R44 goes back in, the meter needle will be at 0VU(in "GR mode"), and it should read zero volts across "R74"(because of your null adjustments).

To clarify:
Q-bias.
Null adjust.
10db swing.
R44 in.
Tracking adjust.

--Brian
Title: 1176LN Rev D DIY
Post by: JdJ on July 25, 2007, 05:18:47 PM
Thanks for the in depth post Brian-  I really appreciate it!

:guinness:  :guinness:
-Josh
Title: 1176LN Rev D DIY
Post by: Bri on July 25, 2007, 06:35:14 PM
No problem....hope it helps.   :sam:

-Brian
Title: 1176LN Rev D DIY
Post by: JdJ on July 29, 2007, 11:39:03 PM
Uggg-

I feel really stupid at this point...  I have attempted to calibrate this thing at least 5 times now.  Now I have R44 socketed so I can go back easily.

1. I start by Q biasing with ratio set to 20:1 & input signal of .775v (0db)  I get the 1db drop on my DMM & PT metering, but the internal meter reads more than a 1db drop?!  After setting as Stagefright13 recommended above.  (Both channels are Sifam AL19s)

2. I set the null adjust/ Meter 0 with no input signal

3. Get a 10db swing confirmed by DMM and meters in PT as described in the Urei calibration instructions w/ ratio set to 20:1

4. Make sure with no input signal I'm still at 0 on internal meter and 0.00v across R75

5. Plug in R44 after setting it to approx 1kOhms and immediately my meter drops to -10 in GR mode WITH NO INPUT SIGNAL PRESENT!  If I try to adjust it so I get the correct reding on the internal meter, I run out of range on the Tracking Adjuster.  End of story.

Maybe I wired something wrong?  I have X & Y connected to pins 2 & 3 respectively.  The Red & Blue wires coming off of the OT are also connected to 2 & 3.


Anyone have any ideas?  I'm stumped for the time being...  Both channels of my dual are behaving this way.  I have double checked all of the connections between the motherboards and the ratio/meter boards.

Thanks for spoon feeding me...
 :sad:

Josh
Title: 1176LN Rev D DIY
Post by: Bri on July 30, 2007, 03:50:23 AM
Hey Josh.

It's hopefully just some confusion in the calibration procedure...seems that way since both meters act the same.

Meter needle drops to -10VU with no signal?
What happens when you inject the signal then?

From what you wrote, two things came to mind, however, ignore any incorrect assumptions.

During tracking adjust, it sounded as if you were using R44 to try and adjust to 0VU instead of using R71?
Still, -10 initially, with no signal, that may be a little far in regards to the needed trim ranges in the tracking procedure...but maybe not.

Secondly, were you implying that you were in GRmode during the Qbias procedure? Or did you just note the meter's position before and after?
If you're using the unit's meter to make the Qbias adjustment, make sure you short pad 22 to ground, so you're basically in "GR bypass" but still have the meter function...don't Qbias in GRmode, of course.  That could be suspect.

In regards to tracking adjustments, I assume in lieu of "shorting pad 22 to ground," to keep the meter functioning whilst bypassing GRmode, you're just muting your source signal?
I did the "short pad 22 to ground" to be on the neurotic side, but you should be fine the other way.

So when you're sure about your Qbias, and have then done the Zero meter, 0volts across R74 step....
Here's an outline of my tracking adjust method...maybe it will help:


R44 in
GRmode(20:1)
Your controls set for the 10db swing(10db of GR)
Your source signal coming through...being compressed.

Now, adjust your meter needle to -10VU using the R44 "tracking adjust" trimmer(reflecting the 10db of reduction).

Now, mute your source signal(or short pad 22 to ground), and adjust the needle back up to 0VU using the "0 Set"(R71) trimmer.

Now un-mute your source signal again(or un-short pad 22), and readjust R44 trimmer so the meter needle again shows the 10db of gain reduction(-10VU).

Mute the source signal(or short the 22 pad), and again use the "0 Set"(R71) trimmer to adjust the meter needle back to 0VU.


You should see a slight bit of change(for the better) after each adjustment cycle.

So, repeat this back and forth adjustment procedure until the meter finally holds it's adjustments...
i.e., the meter needle will eventually hold at -10VU when you have the source signal present, and then go back to 0VU when you mute the source signal(or short pad 22 to ground).
Getting to this point usually requires many repetitions of that adjustment cycle.


Is any of this relevant to your troubles then?  I'm getting tired of typing. ;)

--Brian
Title: 1176LN Rev D DIY
Post by: JdJ on July 30, 2007, 11:24:04 AM
That seemed to do it Brian!  Thanks!  I guess my issue was that I didn't realize that the "null adjust" was used to bring the meter back to zero during the tracking adjust phase of the calibration.  The JBL instructions mention the adjustment through the front panel on a 1176 (which I don't have), so I was assuming they meant the zero adjust.  I was also assuming that the null adjust should stay put after doing the meter/null adjustment.  You did mean Null adjust and not meter zero adjust, right?  Where were you getting you calibration info from?  I forgot to check the Gyraf site...

Thanks again-

I'll have to run it through some tests after work, but all seems well.

You guys rock!

 :guinness:  :guinness:

Josh
Title: 1176LN Rev D DIY
Post by: Bri on July 30, 2007, 01:50:34 PM
Whoa, my bad, I did mean the "0 Set" Trim.
I'll  re-edit my post so as not to confuse anyone even further.
Thanks for pointing that out...It was 4am here when I wrote that.
Of course, now you may be back where you started.
But, I'm sure you'll figure it out soon.

--Brian
Title: 1176LN Rev D DIY
Post by: kato on July 30, 2007, 08:31:09 PM
Brian, I just wanted to say thanks / show my appreciation / send you some beers  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness: for the step-by-step calibration procedures.

I have been wading through posts with conflicting information, apparent  misinformation and posts specifically for non-clones with attack switches. While the info in the original manual is certainly sufficient for more experienced users, your detailed steps saved me from banging my head against the wall.

Once I figured everything out, I vowed to make a detailed calibration page but your instructions have pretty much rendered that need obsolete. Thank you for taking the time to share in newbie language what must have taken you many hours to figure out.    :thumb:   Kato
Title: 1176LN Rev D DIY
Post by: Bri on July 30, 2007, 11:44:27 PM
Hey thanks Kato.

If I can spare you the hours of frustration, well then I'm glad to be of help.
It's so simple too.....think of all the needless suffering.

Just think, mnats is probably rolling his eyes about now,
dumbfounded by how the calibration procedure could become the most difficult part of a first time build. LOL! ;)

Cheers,
Brian
Title: 1176LN Rev D DIY
Post by: Stagefright13 on July 31, 2007, 01:37:55 AM
I had trouble myself so don't feel bad. First time I didn't use discrete directions. Now I would like to build another but took alot of work to get the parts for this one!

Wish I coulda help a bit better but has been a while since I did the Calibration.
Title: 1176LN Rev D DIY
Post by: Ilya on August 19, 2007, 01:39:22 PM
I'm going to home-etch some Rev D pcbs 'cause they are not available... I found out that both meter and ratio boards differ from mnats g1176 (at least on the photos they are different, I'm talking about rotary version). I can't find any info about these small boards (except input trafo pcb). Can somebody point me in the right direction? Or at least tell me what for is the trimmer used on the ratio switch board? Thanks!
Title: 1176LN Rev D DIY
Post by: mnats on August 21, 2007, 06:12:23 AM
Quote from: "Ilya"
I'm going to home-etch some Rev D pcbs 'cause they are not available... I found out that both meter and ratio boards differ from mnats g1176 (at least on the photos they are different, I'm talking about rotary version). I can't find any info about these small boards (except input trafo pcb). Can somebody point me in the right direction? Or at least tell me what for is the trimmer used on the ratio switch board? Thanks!

http://www.groupdiy.com/index.php?topic=258435#258435

It's kind of crazy referencing an earlier part of the same thread each time someone asks a question, so you might want to try a search next time. That's how I found it!

If you are going to try a home-etch, make sure you remove the extra base pads from the top layer of the GR Control Amp section.
Title: 1176LN Rev D DIY
Post by: Ilya on August 21, 2007, 07:08:31 AM
Thanks, mnats.
I was re-reading the thread once again and found that post. Probably I missed that 'cause there're only 2 posts about that trimmer and I skipped them.
Thanks for reminding about the base pad - there's plenty info here, so I won't miss that one :)
Title: Output really hot
Post by: Arrigotti on September 07, 2007, 03:31:40 PM
I finished up my REV. D  1176, and have calibrated it, (at least I think it is calibrated correctly).

The problem I am having is that the output is really hot.  I have to turn the output pot almost down to nothing to make sure that I don't clip my converters.  The input is set so that I am just starting to get some compression.

The compressor is compressing, and the audio sounds fine (no nasty distortion).

Any thoughts?  I know, check all the connections and component values and also check for solder blobs.

Beside that, any thoughts, or at least a starting point to check?

Thanks,

E. Arrigotti
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 07, 2007, 06:42:36 PM
Well, here I go again answering my own question:

The output pot was wired backwards, but now I have another problem:  It isn't compressing now.  I am royaly stumped on this.  It isn't just the meter either.  I can't hear any compression.

I checked the voltage at point 7 and 19, and it is about -1.3v no matter where the input or output is set.  (This is in GR mode)

Any thoughts?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on September 07, 2007, 09:17:17 PM
Been using mine ALOT but the vintage 1985 input pot is very scratchy now. Or if I can clean it? Sigh... Anyone know of a replacement? I would like to get A real one from Andrew at Purple. But would hate to bother him...
Title: 1176LN Rev D DIY
Post by: Stagefright13 on September 07, 2007, 09:41:03 PM
Arrigotti Did you set the FET into conductance range? After that it is just a meter thing. And I will vouch it being a great compressor!

And pots may seem to work in reverse on 1176 Or Purple. Attack is faster clockwise and same as Release.
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 07, 2007, 10:53:42 PM
Quote
Arrigotti Did you set the FET into conductance range? After that it is just a meter thing. And I will vouch it being a great compressor!


If you mean did I set the Q-BIAS, then yes I did, and I double checked it a few times also.

On a side note, I do like the sound of the signal chain.  It seems to tighted up the low end, maybe taking out some of the low-mid muddiness?

I'm gonna poke around a bit more.....
Title: 1176LN Rev D DIY
Post by: Siegfried Meier on September 08, 2007, 12:23:18 PM
Hey guys,

I'm doing a pair of Rev D's and I have a couple of extra Lundahl 1540 input transformers laying around.  I know that the transformer board will accept it, but I haven't seen anyone using it for a Rev D.  Any reasons, other than it won't be original, why I shouldn't use them?

Also, I'm looking for a pair of T-pads.  Anyone got any leads on some?

Thanks,
Sig
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 08, 2007, 06:09:24 PM
Okay, so here is some further development in my troubleshooting woes:

I figured out that the compressor actually does compress, but only when I feed it a signal with peaks.  If I feed it a test tone, it doesn't really show compress, or at least it doesn't show it.

The other strange thing, that is probably related, is that when I switch the to GR OFF mode, the output drops quickly, and then ramps back up, and usually past where it was before (I assume because it isn't compressing).  When I switch the GR back in, it drops quickly and then slowly comes back up.   The Attack and Release knobs have no effect how quickly it comes back.

I am stumped again.....

Maybe a problem with the 2N3708's?  I just put them in as I didn't really know how to test them.

Maybe a wrong/bad electrolytic?
Title: 1176LN Rev D DIY
Post by: kato on September 08, 2007, 08:04:14 PM
Quote from: "Arrigotti"

I figured out that the compressor actually does compress, but only when I feed it a signal with peaks.  If I feed it a test tone, it doesn't really show compress, or at least it doesn't show it.


It could be
that your compressor
is working just fine.   :thumb:
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 08, 2007, 08:32:27 PM
Quote
It could be
that your compressor
is working just fine.


I wish...... but I've built a few of the regular Rev. F ones and I had no trouble feeding the unit a test tone to calibrate the meter tracking.  They have always resgistered the compression with a sine wave.

The way I have this unit now, I am unable to calibrate the tracking since it won't compress if I send it a sine wave (or at least the meter section doesn't show compression.  

BTW, I like your Avatar.  It reminds me of my childhood.  Oh the hours I pissed away with the Atari 2600.
Title: 1176LN Rev D DIY
Post by: kato on September 08, 2007, 09:12:38 PM
Quote from: "Arrigotti"

I wish...... but I've built a few of the regular Rev. F ones and I had no trouble feeding the unit a test tone to calibrate the meter tracking.  They have always resgistered the compression with a sine wave.


Oh I misunderstood. That sounds like how it would act under normal operation. But you're in calibration mode. Sorry. Something wired wrong with the bypass/GR switch? (I wish I knew more to help.)

Quote from: "Arrigotti"

BTW, I like your Avatar.  It reminds me of my childhood.  Oh the hours I pissed away with the Atari 2600.


Defender was my first cartridge.
Sometimes it makes me sad that I wlll never enjoy a video game as much as Defender. 3D games make no sense to me.
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 10, 2007, 12:31:17 PM
This has been the most perplexing troubleshooting I've ever done.  I have always been able to troubleshoot my builds and they all work now (Four 1176's, Chimera, Bellerophon, LA2A, Four Channels API, Two SSL's, as well as several guitar amps).

So upon further investigation, probing, and re-soldering if wires that broke off, here is what it seems like the main issue is:

Compression is directly related to the level of the output.  When I have the output low, there is no compression, but when I push it up, I can get much more compression.

By looking at the schematic, I can see that the top leg of the output pot it tied to the compression circuit, but I can't figure out how it is acting as a threshold as well as an output pot.

Any help would be appreciated, even if it is just a starting point.

Thanks...
Title: 1176LN Rev D DIY
Post by: Arrigotti on September 10, 2007, 01:24:24 PM
All right.......I guess this is just my personal DIY troubleshooting BLOG, but I fixed it.  It works perfectly now.

Sometimes I guess it just helps to write it out so that you can get your head outside of it and see it from a different perspective.

So what was the issue?

The wiring from the main board to the ratio board to the output pot was a little mixed up.

I realized that that was were the problem was after I posted my problem and thought about that section of the circuit.

Thanks for being my cyber-sounding board.

Maybe this will help someone else in the future.

Thanks!! :green:
Title: 1176LN Rev D DIY
Post by: Siegfried Meier on September 22, 2007, 09:31:51 PM
Hey guys,

I need to purchase a pair of T-Pads for my Rev D's. Andrew at Purple has 2 different kinds:

Clarostat J series, two decks - $76 each
Clarostat 70 Series, three decks - $60 each

Does anyone know which one would be the best to use? I'll probably be using Cinemag ins and outs.

Thanks,
Sig
Title: 1176LN Rev D DIY
Post by: codered on September 22, 2007, 10:57:01 PM
Check Leeds ..they had the Mallory for $40 a couple of weeks back
Title: 1176LN Rev D DIY
Post by: sysexguy on September 23, 2007, 12:24:05 AM
so I bought 25 2n3707's and...well if we were in baseball, it would be 9th inning, 1 out with a perfect game - no hitter (hfe speaking)....none are up to the task.

Can I try a substitute, if so, what and are there any things that must then be accounted for (other than the calibration) 2n3711? the 5088's(?) that purple uses?

Thanks,

Andy
Title: Leeds?
Post by: plexirob on September 23, 2007, 02:51:02 AM
Hi, leeds where can I find them? I'm also in the T600 hunt!

Thanks,
Title: Re: Leeds?
Post by: codered on September 23, 2007, 01:15:53 PM
Quote from: "plexirob"
Hi, leeds where can I find them? I'm also in the T600 hunt!

Thanks,


http://www.leedsradio.com/parts-resistors.html#potentiometers

and a kind request( for everybody)  please dont buy a whole lot for hoarding..that's what happened the last time he got a bunch.
Title: 1176LN Rev D DIY
Post by: Bri on September 23, 2007, 03:11:54 PM
Andy, go with the 2N3708's as a direct, "no worries" replacement.
They should be fine, in regards to the necessary HFe.
But measure them anyway. ;)

--Brian
Title: 1176LN Rev D DIY
Post by: sysexguy on September 23, 2007, 04:15:28 PM
Thanks Brian....they're showing b/o at mouser so luckily I have 70 other projects on the go  :roll:

Andy
Title: 1176LN Rev D DIY
Post by: Neeno on September 30, 2007, 10:54:26 AM
Hi guys !
I'm finally building my 1176 rev D
But i'm having some troubles figure out how this thing should be connected...

I'm using the PEC Bridged-T Attenuator, Mnats Trannie PCB sruffed with the altran C3837-1 going to the 1176 board.

Does anyone have a wiring diagram for this ?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on September 30, 2007, 03:33:02 PM
That info is in this thread back a ways.
Title: 1176LN Rev D DIY
Post by: Neeno on October 01, 2007, 03:35:39 AM
I've found the following diagrams:
(http://stephensheath.com/Tpadcheck.JPG)

and this
(http://www.hostpic.biz/uploads/a91e71ade7.gif)

but honestly i can't get them ?!?!

So I followed the schematic and i came to this:
(http://www.studio21.ch/temp/t-attenuator.jpg)

Now the question is... wich one is the right one ?

I'm trying to test it using my signal generator and the oscilloscope, but the level one the altran output is not changing...

Yesterday i was trying to cablibrate my unit, i completely removed t-attenuator and the trannies and i fed a signale directly to the input of the 1176 board. It looks like the unit is compressing and there is GR (shown also by the VU meter) but in GR the meter behaves in a strange way.

It looks like the ballistics are bad, even if the meter is right, i'll try to explain but it's not easy and my english should be even worse...

I set the compressor for 10dB gain reduction (shown on the meter), then i switch off my signal generator, the gauge goes back to 0dB (GR) but it oscillates for some seconds, that happens even when i change the ratio...

What could it be ? A wrong component ? Wrong wiring ?
I triple checked everything but i can't get it right...


Can anyone help me ?
Title: 1176LN Rev D DIY
Post by: Neeno on October 02, 2007, 11:02:08 AM
It looks like I solved the T-Attenuator problem...
I'll check it out again tonight...

Now it looks like i can't solve the GR meter problem...
I calibrated the unit properly, following the JBL manual, i did the repetitive steps more than 5 times to be sure but my meter is still WOBBLY when in GR mode... even during the -10dB calibration, when i mute the signal it goes back to 0dB but it swings for 2-3 seconds before stop...

Is it right ?
Am I missing something ?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 05, 2007, 04:21:25 AM
Your meter swings back and forth or takes a bit to settle? And what meter are you using? Maybe it is on slow release? I have the 3 deck Mallory so I couldn't help you with the PEC sorry bout that. Also the meter on mine tends to rise after prolonged use. Also stated in the Urie manual. A max of +1 tho.

Does it sound good? After the bias adjust it is all just meter anyway. Mine calibrated fine after hours of learning... But in use the needle is flying around. It is a fast compressor. I really don't look at the meter as much as I did at first. But when I do glance over sometimes it does quick peaks to 20db reduction. But is just the sound I want. :)

And the 3708's I got ALL tested good hfe. And sounds great. My Mallory is scratchy now tho I may have to replace it with something.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 05, 2007, 05:15:48 AM
Andy email me with your address and I can send you the 3708's I have a dozen left. No charge. And I will test them first also.
Title: 1176LN Rev D DIY
Post by: pH on October 18, 2007, 05:57:28 PM
Well I finally have mine together in a nice case from Tat. I'm using a Lundahl Y236105 which gives 22VAC, I fired it up and I'm only getting 28.7VDC on the rail. Should I worry about this being too low? I was able to go through all the other calibration steps successfully, and it still sounds GREAT.

The other thing is that my ratios are backwards!?! I wired a rotary slam switch following Mnats picture guide and thought I had it right, but to my ear  clearly 4=20 and 20=4. Slam is still all the way to the right, but the meter pegs all the way past the red when no GR is happening. Ideas?
Title: 1176LN Rev D DIY
Post by: gevermil on October 18, 2007, 07:00:43 PM
Yep , I wired mine as shown and I have backward ratio as well  :wink:
Sounds good though
Title: 1176LN Rev D DIY
Post by: Bri on October 18, 2007, 11:47:44 PM
Hey guys.

On my build, my ratios also seemed backward...to my ear, and meter.
I had no previous experience with the specific characteristics of the 1176's ratios, thresholds, etc.

I came across a post from squib which was very helpful.
Using his method, I ultimately found that my ratios were actually correct.

I'm still a newb, so forgive me if you're aware of this already or if it doesn't pertain to you at all.

Here's his post:

"forget the meter for now
you need to set up a jig to test the ratios
ensure that as you test each ratio that you push the unit into 3dB of GR, then up the input level by exactly 10dB without touching any of the 1176 controls and measure the change in output level. For 20:1, you should see about 0.5dB increase, for 4:1 you see about 2.5dB increase etc etc.

You need to prove the sidechain / ratio circuit first before investigating the meter. Make sure you reset the unit for the 3dB of GR when testing each ratio."

Cheers,
Brian
Title: 1176LN Rev D DIY
Post by: pH on October 19, 2007, 01:53:49 PM
I admit it can be tricky to tell 4:1 vs. 20:1 compression when the output volume changes, but I'm still not convinced all is right.

I'm running a mono drum mix through at 4:1 and it sounds pretty crushed. When I step up towards 20:1 (without changing input or output volume) it gets increasingly LOUDER with more transient peaks, much less compression happening. Others on the G1176 thread have said volume will go down with increased compression ratio (as it should), but the opposite is happening here. Does the whole input gain structure change with the ratio switch?

Slam is working fine, but in this mode my meter still pegs to the right with no signal, moves left with gain reduction. Meter seems to work fine in other modes.

Hmmm... :?
Title: 1176LN Rev D DIY
Post by: Neeno on October 19, 2007, 02:12:17 PM
Your meter is right...
That happends also in the original units...
When you swich all 4 buttons in (or to the slam mode on the rotary) the meter pegs all to the right !
Title: 1176LN Rev D DIY
Post by: edanderson on October 19, 2007, 04:27:02 PM
on the 1176, changing the ratio changes the threshold.  the higher ratios have a higher threshold.

ed
Title: 1176LN Rev D DIY
Post by: pH on October 19, 2007, 05:50:05 PM
OK, now that makes sense. Thanks fellas.

BTW, thanks Ed, Mnats and everyone else involved in this project. I'm so excited to have a piece of gear this fine.
Title: 1176LN Rev D DIY
Post by: sysexguy on October 20, 2007, 12:20:58 AM
John, thanks ever so much, the build continues!!!!

Andy
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 20, 2007, 09:25:10 AM
No problem Andy. Enjoy your build!
Title: 1176LN Rev D DIY
Post by: tommypiper on October 29, 2007, 11:21:23 PM
Hi guys, I've been away a long time due to family comittments... I'm trying to catch up with my build.

Is it possible your backwards ratios are from soldering to the wrong side of the ratio board?  Which side did you put the switch on?  The silk screened or the other?

I read MNat's explanation about the R-Opti1 trimmer on the ratio board.  And I see the "invisible" writing on the back to cut the link... but does this give a higher or lower threshold?  Is it then set to higher or lower?  I totally do not get this.

I'm also confused about the meter board and switch. How do I wire this with a toggle instead?  I mean, what is the Y and X?  Do they attach to something?
Title: 1176LN Rev D DIY
Post by: CJ on October 29, 2007, 11:25:50 PM
Todd, go back to your corner.
Did I say you could come out?
Remeber, no LA2, no Freedom.
You have it built then right?
 :razz:

Ok jus chill, already.
How is the elbow grease box doing?

I still say that avatar looks like Bolin on Private Eyes.
Title: 1176LN Rev D DIY
Post by: tommypiper on October 30, 2007, 12:07:39 AM
Thanks for the encouragement.

I have no idea who Bolin is or who Private Eyes is, or what.  I don't even know who your avatar is.  (Mine is a potrait of me from 1783.)

Yeah, maybe the LA2 would be easier.  I'm feeling a little lost at the moment overall.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 30, 2007, 05:16:42 AM
CJ's Avatar looks like Lemmie from Motorhead but I could be wrong lol...
Title: 1176LN Rev D DIY
Post by: okgb on October 30, 2007, 08:58:00 AM
Tommy Bolin , made a mark on the rock world  [ only a footnote ? ]in the 70s
Spectrum with Billy cobham was a good moment from him as well as his first two releases ,
one of the early guys to Jam with Jan , not a superstar
i'd say but he had his own vibe which is more than most can claim these days , also played with deep purple for a stint but already too smacked up by then . [ oh that sexy second cover with the oriental girl ]

 Nice work on the 1176s  , this thread will help when i finally get to mine
Title: 1176LN Rev D DIY
Post by: tommypiper on October 30, 2007, 12:02:26 PM
I'm hopelessly out of the loop in more ways than one. I have heard of Billy Cobham, the rest is over my head.  I must be too young, or too old, or both.  :grin:

Back to topic, what is the function of the meter switch?  I know the original push-buttons show GR, output, +4, -10...  But the schematic shows only a two position switch.   So what functions is the switch?
Title: 1176LN Rev D DIY
Post by: CJ on October 30, 2007, 09:24:46 PM
hey, a rare video, chk it:

http://www.tbolin.com/audiovideo/index.html

more on youtube:

http://www.youtube.com/watch?v=Squ4C6919aY

Todd, don't sweat it.
We will build an LA2 in one day, just to show these punks whats up.
cj
Title: 1176LN Rev D DIY
Post by: tommypiper on October 30, 2007, 11:22:38 PM
CJ, I was just watching yer Tommy B and the earth shook.  Man.  I guess he made the earth move.  My avatar does look like him and my handle namesake as well, well, cosmic.  Or earth shaking, anyway.  I hit him up on the video.  

Thanks for not taking the piss out of me again.  I haven't given up on the LA2, it's gonna happen.  In fact, I was going to buy some parts from you but you never replied to my emails, so I gave up.  What's up with that?  You living in a tree house with free WiFi now?

Don't wanna waste two much bandwidth here off topic.  Has anyone built this 1176 with a meter switch toggle, GR and output?  What resistors in the schematic do I include, if any?  What is the schematic showing the switch doing, anyway?  I can't figure out the circuit by reading the schem, I'm an illiterate musician.  I know it's only a click away.. ha ha.. heard that one before.  But, duh, I dunno where to click.  Already clicked all over.  As usual, I'm missing something.  Over and out.

The earth did move.  The winders rattled.  The foundation shimmied.  I'm going nuts.  DIY is my undoing.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 30, 2007, 11:47:18 PM
I built one with pushbuttons. I used the Purple schematic to wire them.

http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf

I also used the original schematic from the JBL pro site.

http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf
Title: 1176LN Rev D DIY
Post by: CJ on October 31, 2007, 02:16:21 AM
actually, that video was crap, i didnt even watch it, he looked junked out.

hereis a studio track no video, kind of cool
i have orig 5532/34 Siemens, "the kind" opamps, gotta builsd a 1176 also.

http://www.youtube.com/watch?v=jqKZEoY1rgU
Title: 1176LN Rev D DIY
Post by: tommypiper on October 31, 2007, 12:06:14 PM
Thanks, John.  I know, those related docs are even more confusing to me.  I see the X and Y points in the Urei schem, but I don't know where they go and I don't know what they're doing on our project.  The Purple schem is even wilder.  What I don't get is why Mnat's schem has all those poles showing and what do they do?  When the meter board is 4 pole, but the schem shows 6 poles, two position.  So maybe he is only switching some of them at some of the time.  Seems to me the GR works by reversing the voltage polarity to the meter.  But why is it so complated with all the poles? I'm lost about what all those poles and the whole network is about.  The Purple is even introducing a meter buffer, so apparently the meter amp is not buffered from the audio?  Huh?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on October 31, 2007, 06:58:11 PM
I'll get back to you shortly but I am sure I can help you. Passing out Halloween candy right now.

How many positions on your switch? 4? Then you would use GR, +8, +4, and off. This is for the gain reduction switch. Correct? THAT I can help with just tell me what you want exactly. I did the pushbuttons point to point.

You can also rig an all buttons IN with the rotary. And the original URIE had no buffer. Purple made some upgrades to the design. Including true bypass. Very well done I might add. However it took me ALL 3 schematics to build mine.

More switch info here:

http://geocities.com/m_natsume/1176_slam_mode_rotary.html

The slam mode is not critical tho. I have used it and it is interesting. But I never actually recorded anything with it yet.

The switch has only 1 common that switches between the row of resistors. Check schematic again.
Title: 1176LN Rev D DIY
Post by: CJ on October 31, 2007, 07:50:54 PM
ok ,here is TB with his witchy woman, tell me that aint tommy piper ?
I knew that was a match, kept buggin me, where have I seen that dude.


(http://vacuumbrain.com/The_Lab/Misc/sq/tomc.jpg)
Title: 1176LN Rev D DIY
Post by: tommypiper on October 31, 2007, 10:32:11 PM
All right, CJ.  Busted.  Got me.  I've been trying to conceal my identity, but now I've been outed.  On an 1176 thread to boot.  Man.  You coulda at least lured me into an LA2 thread.  Or something with tubes, or Neve, or something.  Just don't ask me to sing next time I see you. :cool:

(http://i82.photobucket.com/albums/j243/tommypiper/IrishPiperc1843.jpg)

Sf13, thanks.  I just sent my kids out the door with flashlights and their mom.  :grin:

Yes, there's enough info out there to do the pushbuttons p2p. I've seen a lot of that, thanks.  I'm trying to do a toggle instead, so I'm not clear what to include, how many poles, etc.  I was originally trying to decode the schematic, which I can't do.  I mean, it looks like a 6 pole two position switch.  But is it?  What does what?  What does the rotary version do?  (Where is the documenation, hello?)  Banging my head on the wall.  I'll try to translate the pushbuttons to a toggle.  So, is Mnat's schematic showing all those poles because they are the original pushbutton configuration?  If so, how do we know which switch does what?  And if so, how does the rotary switch fit in?  As you mention, I'll have to use all three schematics to make sense of it for the pushbuttons configuration.  Then try to translate that to a toggle.  I got very sidetracked trying to go the other route - understanding it in a rotary configuration first, which I still don't get.  BTW.  Do you know what the X and Y points are?  Since our project doesn't have a buffered meter, I guess I need an off position to keep distortion to a minimum at times.  So that would mean I'm building a three position toggle: GR, +4 out, and off.  

Re Slam, I have not tackled the ratio switch yet.  One switch at a time.  :guinness:
Title: 1176LN Rev D DIY
Post by: tommypiper on October 31, 2007, 10:50:03 PM
OK, that already helped, Sf.  Thanks.  I think I'm getting it.  X and Y are the output transformer outs.  That's what feeds the meter when it's reading output level.  UNBUFFERED.  The Purple schem makes things much clearer.  I'm not sure how to translate it to Mnat's schem.  (I'm a poor schematic reader, I get physically dizzy.)  But I think I need a 2 pole, three position toggle.  

Follow up.  It looks to me when it's in GR mode, the meter is fed by the meter driver circuit, and is not connected to the output transformer at all.  I'm not sure if this would introduce distortion into the audio, via the meter driver circuit.  Can anyone say?

If no distortion, then one doesn't really need an off position in the switch.
Title: 1176LN Rev D DIY
Post by: tommypiper on November 01, 2007, 12:37:02 AM
OK, I finally got on the right track.  (The key to understanding the schematic is that the meter switch is not a 6 pole single throw, as it appears.)  I have it figured out.  I made a drawing for a DPDT toggle.  I'll post it if anyone wants to see it.

However, I can't understand how to connect it to the board in real life.  I see these numbers on the small meter board, and I guess these connect to the same numbers on the large pcb?  Is that the idea?  Connect the numbers.  Have I missed some documentation somewhere?  One of the numbers is 4, but I cannot find any 4 on the large PCB.  Heck, why make it easy?  I'm supposed to know it's the left leg of the third transistor on the fourth plane of the dehummifier reducer?  Got it.

The other numbers are oddly out of sequence, 22, 29.  Why not start with 1?  How did you connect your pushbuttons to the main PCB?  I don't understand the logic to these numbers. And more frustrating, they are not on the schematic.  Again.  Mm.  How do I know what I'm connecting?  I guess we have to follow traces and try to deconstruct the PCB layout?  OK... Again, I don't understand why so much is left out of the documentation.  

BTW, what is the single switch shown just above C17 below the ratio switch?
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 01, 2007, 11:10:21 AM
The switch above c-17 turns gain reduction on and off. (Off is switch to left) You will want that on your toggle. I traced the board to figure out wich wire went where. And I checked each off on the schematic with a pen as I went. I personally leave mine on GR all the time. Have no need for an output meter. And no distortion occurs cause of meter. It's how the original was.

Off on the original turns power off. On mine I hooked it to turn gain reduction off and used a switched IEC. You can run stuff thru the 1176 without gain reduction and still get the transformer and FET sound. So off is useful.
Title: 1176LN Rev D DIY
Post by: okgb on November 01, 2007, 11:15:59 AM
It's good to have the v.u. option , as sometimes the levels can creep up
before you notice switching to the meter to see that's where the level is pegging in the chain .

An off position is not bad either if the slam mode gets too disturbing
pinning the needle .
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 01, 2007, 11:17:27 AM
True. But I am using Protools and my converters will be slammed long before the 1176 :)
Title: 1176LN Rev D DIY
Post by: okgb on November 01, 2007, 11:21:14 AM
I'd still do it myself considering the black version had an attenuator before the input xfmr to give you an idea of what's going on in the unit ,
but true most people just leave it on G.R.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 01, 2007, 11:25:52 AM
Wow Tommypiper robes and a straw hut. You guys musta been on some serious stuff!!
Title: 1176LN Rev D DIY
Post by: tommypiper on November 03, 2007, 09:02:23 PM
John, and ok, thanks for the info, very helpful!  Do you happen to know where the connection point "4" is on the main pcb?  It is supposed to connect to the meter switch, AFAIK.  There are other numbers on the meter switch board which correlate to connection points on the main PCB, but there is no "4" on the main PCB.  Just in case you have your notes handy.  Overall looks like I'll have to follow traces like you did, I guess.  

Would have been so easy to just label things originally, but oh well.  Can't have an easy build, no matter what.  There must be some hidden logic to the odd numbering scheme.  Not related to part numbers?  Not related to a grid?  Mmm.

Yes, put me in a robe in a straw hut with my hand on a woman's knee any time.  Just get that photographer out of here.  Or was it CJ?

cheers,
-"Tommy"
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 04, 2007, 01:44:27 AM
Yes the Photographer was CJ lol

Truthfully I traced the board at every connection and checked it off on a printout I had.

It's not a walkthru type of project. You will have to learn some stuff to make it. But was and IS one of the best sounding projects ever.

I didn't go by numbers I went from schematic. So can't help you on that. I didn't even have the rotary boards.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 04, 2007, 01:04:56 AM
Actually I prolly have the rotary boards here somewhere. So if someone needs a set lemme know. I will dig them up. :)
Title: 1176LN Rev D DIY
Post by: mnats on November 04, 2007, 07:08:01 AM
Quote from: "tommypiper"
Do you happen to know where the connection point "4" is on the main pcb?  It is supposed to connect to the meter switch, AFAIK.  There are other numbers on the meter switch board which correlate to connection points on the main PCB, but there is no "4" on the main PCB.

There is no "4" on the main PCB. The other "4" is on the Ratio Swich rotary board, just as in Jakob's original 1176 rotary switch design. Wiring the rotary switches is explained on my rotary switch wiring page (http://www.geocities.com/m_natsume/1176-wiring-rotary.html).
Quote
Connect a wire to pad 4 on the meter board. Note that the designation "4" doesn't show up anywhere on the 1176 schematic, it's a marker unique to the clone...Wire the other end to pad 4 on the ratio board, right next to where the output pot wires go.

Quote from: "tommypiper"
Would have been so easy to just label things originally, but oh well.

Really? What would you call an unlabeled connection from the schematic on the PCBs?

I thought Jakob's numbering scheme was fine - the number 4 isn't duplicated elsewhere on the schematic and it can't be mistaken for anything other than a connection between the two rotary boards.

Quote from: "tommypiper"
Can't have an easy build, no matter what.

Right. When I decided to offer PCBs of this build, I included this caveat in the first post:
Quote
Please note that this is not a "G1176" type project. You must be able to read a schematic, have the patience to read about and locate difficult to find parts and be prepared to think for yourself. If you have any doubts, start with a Revision F/G type project.

I wasn't being condescending, I was just trying to make it clear that it doesn't make a good one-evening project or a way to get a "cheap 1176".
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 04, 2007, 11:15:28 AM
MNATS is right. But Damn it if it doesn't make a beautiful sounding compressor!! And a good learning experience too. At least for me. Thanks MNATS for the great design. And if I may say so I am very proud of my work and what I learned in the process. I am sure others will agree. It wasn't easy but was extremely rewarding. I reap the benefits every day. :thumb: I WISH I could assemble the parts to make another.  

Thank You!
Title: 1176LN Rev D DIY
Post by: tommypiper on November 04, 2007, 12:15:02 PM
I'm sure it sounds great.  That was apparent right away to me.  In fact I am going the extra mile to use quality parts and do things to maximize its potential the best I can.

Nice to hear from Mnats.  I don't think anyone is expecting a G1176, whatever that means.  Just basic documentation.  It's just the Rev D documentation is incomplete.  Yes, how can we know what connection point is what?  It's not on the schematic.  Seems odd not to put it there when it's on the PCBs, right?  :wink:

Wow.  I had never seen that switch page, it's quite amazing, thanks.  It's not the Rev D project, so I never came across it.  We would never have known.  And we're supposed to reference Jacob's G1176 to understand how the Rev D is wired?  I never would have known that either.  

OK.  Thanks for telling us.  I'm sorry, I thought they were different projects.  I've never built a G1176 and I thought the point was to make the Rev D, not a G1176 (as you mentioned).  

I know I'm not the only one who has been scratching my head on these points.  Yes, of course I would figure it out on my own, following the traces, whatever, as John did, but why not ask if there is some logic behind the numbering scheme and other mysteries along the way?  Obviously there had to be, but it was not apparent.  How are we supposed to know that we are to look at Jacob's schematic for the Rev D?  Jacob didn't design the Rev D, the boards, nor a schematic for it.  

You know we love this project and we all appreciate the PCBs.  Don't come down on people for asking questions.  This is the first 1176 for many of us and we therefore have never seen Jacob's numbering scheme.
Title: 1176LN Rev D DIY
Post by: mnats on November 05, 2007, 06:09:39 AM
Quote from: "tommypiper"
It's just the Rev D documentation is incomplete.  Yes, how can we know what connection point is what?  It's not on the schematic.

The point is that all connections required to get a working 1176 are on the 1176 schematic linked from the first post of this thread. My schematic (from which the netlist was created) exists as the basis for the main PCB. I included it in my document as a courtesy mainly to show the differences between the original and my clone. The differences are noted on my schematic.

Due to time constraints and limitations of the software I used to draw the schematic it does not accurately represent every aspect of the circuit. The input circuit, for which there are many options, is not included at all (but exists on the JBL and Purple schematics also linked from the first post of this thread). But believe it or not, the connection represented by point "4" is there! Point "4" on the rotary boards feeds the connection made to the GR Control Amp when the GR Disable switch is "off", meaning Gain Reduction is "on".

To be honest, the rotary boards were a bit of an afterthought (I did not use them myself) but I figured since many people have built Jakob's G1176 rotary version it made sense to include boards for the Lorlins. I could have just left it completely up to the builder to wire up the external controls themselves since it seems as though many people have gone with a pushbutton option.

Quote from: "tommypiper"
And we're supposed to reference Jacob's G1176 to understand how the Rev D is wired?  I never would have known that either.

If you put the schematics side by side (they are conveniently close on the  JBL document) you'll see that the ratio and metering switching is nearly identical between the Rev D and the Rev F (upon which Jakob's G1176 is largely based). The major differences are in the output circuit and the metering circuit (Class A vs Class A/B; Discrete vs IC). The rotary switch meter boards were designed to accommodate the discrete circuit (reference: third paragraph on my Rev D main page). That paragraph begins with the sentence "Generally, wiring the Revision D is the same as wiring a rotary version of the G1176."

As I've mentioned before in this thread, I can't force you to read my Rev D page. But I would suggest that you read it. It is also linked from the first post in this thread.

Quote from: "tommypiper"
OK.  Thanks for telling us.  I'm sorry, I thought they were different projects.  I've never built a G1176 and I thought the point was to make the Rev D, not a G1176 (as you mentioned).  

My mention of the G1176 was simply in reference to the complexity of the build. If you take a look at the genius of Jakob's design, you'll see that most parts, including the input and output transformers, just drop onto the main PCB. This one ain't that easy.

Quote from: "tommypiper"
Jacob didn't design the Rev D, the boards, nor a schematic for it.

I didn't design the Rev D or the schematic either. I only made PCBs based on the original schematics that have been publicly available for a while now.

Quote from: "tommypiper"
Don't come down on people for asking questions.  

I was baited by statements like

Quote from: "tommypiper"
(Where is the documenation, hello?)

I don't think anyone is expecting a G1176, whatever that means. Just basic documentation.

...and the first statement quoted at the top of this post. So just to make it crystal clear: everything you need to build an 1176LN Rev D is on the original schematic. I have tried to document my PCB and project as best I can. If you think you can do better, by all means feel free to make your own page as others have already done. Thank you for taking the time to read this post.
Title: 1176LN Rev D DIY
Post by: okgb on November 05, 2007, 08:34:32 AM
thanks for making the boards in the first place and this threads reminders
[ like ALL threads ] to read through carefully

[ only have my D version half started , gotta get there ]

regards Greg
Title: 1176LN Rev D DIY
Post by: Stagefright13 on November 05, 2007, 10:49:26 AM
If you go back about 20 pages you will see my completed REV D. I was able to build it all with the info in MNATS post number 1. So it ain't THAT hard. I'm not genius boy lol. :) You'll get it done soon TP!

And would also like to voice how cool it was for MNATS to make such a nice board for this. And he DOES link enough info in post one to get it done. I am living proof!  :thumb:
Title: 1176LN Rev D DIY
Post by: tommypiper on November 07, 2007, 02:45:34 PM
Thanks guys, thanks Mnats.  Sorry, I was just wondering aloud and didn't understand the methodology to the documentation.  Speaking for myself (and I'm sure others) I appreciate all the effort and time which has gone into making the boards and docs and web pages.  A selfless, and mostly thankless effort.
:guiness:

I still don't quite understand the thinking behind the documentation, and maybe I'm seeing something different on my web browser in that first post and your Rev D page (because I'm using a very old browser with no Java, etc), or whatever, because I never saw some of those pages and don't see links or mention of them (like the rotary switch page or the PSU page or any reference to the number scheme from Jackob).  But obviously this has been covered now and we should all get back to build related posts.  

It's not that I'm unable to figure things out (by following traces and reverse engineering it with my own drawings, etc, albeit slowly) -- I just didn't understand the organizational aproach or the method behind it, and wondered why, and what was going on.  

Onward and upward.  I'm glad to be working on these again after a crazy year and now I know where to find the missing pad numbers and we can reference the other build projects, other webpages besides the Rev D (this was not logical to me), and Jackob's G1176, and the historical 1176 docs as needed, as well as the rotary boards page and PSU page.  I think those are all the necessary references now to complete the picture.  Thanks for sharing info in the DIY spirit to all.
Title: 1176LN Rev D DIY
Post by: underthebigtree on November 07, 2007, 05:11:28 PM
Thanks to Tommypiper, Stagefright, and Mnats for explicitly getting all this info together in this section of the thread. I'm just getting to the wiring phase of my units, and having all this in one place will make it easier for sure.

I think that in the case of this particular project, all the information is available, but in disparate places across the net. Tying it all together here will help a lot of us who have not built the 1176 (in any flavor) before.

 :thumb:
Title: 1176LN Rev D DIY
Post by: JdJ on November 28, 2007, 02:12:11 PM
This might sound like a stupid question, but as I haven't really had the opportunity to use an 1176 other than the dual rev D I have built (and software versions).  So disclaimer aside- do those who have built this version find it pretty gritty (especially on higher gain settings)?  Don't get me wrong- I dig it, I just don't have anything to compare it to, and I want to make sure I haven't screwed something up...

Cheers!

J
Title: 1176LN Rev D DIY
Post by: tommypiper on November 30, 2007, 01:28:47 PM
J, sounds like something is wrong.   How's your gain staging?  

I hope to contribute more about my own build soon.  Underthebigtree and I are trying to finish ours by Christmas.  However I've been slammed with family and other work recently.
Title: 1176LN Rev D DIY
Post by: underthebigtree on December 03, 2007, 11:55:38 PM
Looks like Christmas is coming early, TommyP! I just powered up my first unit, and it pretty much all worked perfectly the first time.  :shock:  :shock:  :shock:

It sounds HUGE. Absolutely whisper quiet until I crank the output knob near full, at which time it craps out - I first hear some noise, then some crackling, as the signal disappears. My guess is some sort of RF noise is feeding back and taking over - but what the hell do I know? I was terribly careful with grounding and wiring, and except in edge case situations, it is just fine.

Onward to calibration and figuring out how to mount the damn meter in the hole - maybe epoxy.
Title: 1176LN Rev D DIY
Post by: underthebigtree on December 17, 2007, 12:42:56 AM
So it appears that I was highly optimistic as to my success.

The unit is generating an incredible amount of output - like 21V with the output knob set to halfway. I've gone through the whole thing carefully, replaced Q4 (see below), checked for shorts, and so on. I just can't figure out what's going on.

To start with, here are my test settings:
Input signal: 260Hz sin wave at 0.69Vp-p (-10dBu, 0.448Vac)
Input knob set to 10 (on 0-10 scale), output 0, attack and release fully CW, ratio 1:4, meter knob: bypass

Now here are my readings going through the signal chain to the main board:
Input: 0.448Vac
Hi output of T600: 0.448Vac
(Hi output of T600 at midway setting of T600: .221Vac)
Hi input to Mnats input card: .447Vac
Either output of input trafo (Lundahl LL1540 on Mnats input card): 1.786Vac

So first of all, should the input signal be more than tripled in voltage coming out of the input transformer?

Now here are the readings at my transistors through the signal chain, with the output signal set at zero:

Signal preamp section:
Q1: G=1.62V, D=1.78V, S=1.78V
All the rest are in the order B, C, E:
Q2: 1.78V, 1.78V, 1.78V
Q3: 1.78V, 2.07V, 1.78V
Q14: 2.07V, 1.78V, 2.07

Signal line section:
Q4: 1.79V, 1.79V, 1.79V
Q5: 1.79V, 1.79V, 1.79V
Q6: (didn't measure - has to be done from underside of board)

Now if I set the output knob to 20%:
Q1: 2.6, 3.4, 2.9
Q2: 3.4, 1.7, 2.8
Q3: 1.7, 2.7, 3.0
Q14: 2.6, 3.0, 2.6
Q4: *** (80V?), 1.8, 1.8)
Q5: 1.8, 3.1, 2.1

*** at this setting, Q4 is off the charts when I touch the test probe to the Base pin, and I start to hear a buzzing, ticking sound in my output transformer, which makes me remove the test probe rapidly. WTF?

Now if I set the output knob to 50%:
Q1: 18.5, 21, 20
Q2: 21.6, 1.8, 21
Q3: 1.8, 19.6, 20.7
Q14: 20, 20.7, 19.1
Q4: ***, 14.8, 18
Q5: 16.3, 20.8, 3.6

The first thing I did after taking these measurements was to swap out Q4. No change.

In addition, as soon as I get the output up to about 20%, the sin wave starts distorting asymmetrically on my scope.

Here are the corresponding output voltages, measured at pin 2 of the output XLR, between my unit and a UA 1176 reissue:

Output knob      My unit     1176 reissue
0                      .001V       .001V
2                      2.8V         .068V
5                      21V          .425V


Any help would be greatly appreciated. I've been banging my head against this for a couple of weeks, and don't know where to look next.

-Nick
Title: 1176LN Rev D DIY
Post by: tommypiper on December 18, 2007, 12:29:30 PM
After a cursory glance at your post.  Sounds to me like you have something wrong at the input.  I don't have the docs in front of me and can't remember off top of my head, but I don't think it's a 1:3 input ratio.  Sounds to me there is something wrong with the T-Pad and input transformer wiring.  The distortion you're getting is because the signal is too hot through the circuit.  

We should get together.  Call me.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on December 20, 2007, 07:16:40 AM
The input transformer is a 2:1 for spec. Even using the 2:1 ratio you don't usually have to crank the input much. maybe your input transformer is wired backward as a 1:3?
Title: 1176LN Rev D DIY
Post by: underthebigtree on December 20, 2007, 11:30:38 AM
There's no documentation for the Mnats input board, so I followed the traces under the board, and cross-referenced to the Lundahl pin info for the LL1540.

But this is very useful information. I haven't tried disconnecting the input board from the circuitry that follows and then measuring the voltage, wiring the signal out of the T600 to *either* side of the transformer, and see what ends up coming out the other side.

TommyP, I'll call ya. Let's definitely get together one day this Xmas break - the kids can play, and we can nerd out.

-np
Title: 1176LN Rev D DIY
Post by: radiance on January 07, 2008, 04:10:06 PM
Finished my 1176 today and after some fiddling around it all works.

My PEC attenuator pot attenuates only 8dB. Is this normal?
I wired it like this (this is not correct, read below...)

(http://i241.photobucket.com/albums/ff3/radiance2004/t-attenuator.jpg)

Can someone confirm if this is correct? It seems correct to me but it depends  
on what the purple audio manual means with front deck and rear deck. I thought front deck is the one most close to the frontpanel right?



Edit: wiring diagram is wrong....should do more thinking ... :oops:
Title: 1176LN Rev D DIY
Post by: radiance on January 09, 2008, 06:09:11 AM
Anyone?
Title: 1176LN Rev D DIY
Post by: mnats on January 09, 2008, 07:47:24 AM
The image you posted looks exactly like the one neeno posted on page 29 of this thread (http://www.groupdiy.com/index.php?topic=291418#291418) that he said didn't work correctly.

Here's a scan from the Clarostat wiring sheet which is also a bridged T atten:
(http://mnats.net/images/clarostat_bridged_t.gif)
Title: 1176LN Rev D DIY
Post by: Neeno on January 09, 2008, 07:50:37 AM
Hi Radiance, the wiring diagram i posted is probably wrong...
I'm going to remove the file...

I found out how to wire it, but i didn't redrawn the diagram, i'll check it out tomorrow and make a new diagram...
Title: 1176LN Rev D DIY
Post by: radiance on January 09, 2008, 08:03:34 AM
Thanks all!
Title: 1176LN Rev D DIY
Post by: Nadege on January 11, 2008, 07:06:53 AM
Hello,

I've got exactly the sme issue as Radiance. Did you found some time to redraw the Bridge T attenuator wiring?

thanks  :cry:
Title: 1176LN Rev D DIY
Post by: mnats on January 11, 2008, 06:17:49 PM
Quote from: "Nadege"
Hello,

I've got exactly the sme issue as Radiance. Did you found some time to redraw the Bridge T attenuator wiring?

thanks  :cry:

What's wrong with the drawing I posted above?
Title: 1176LN Rev D DIY
Post by: Nadege on January 12, 2008, 05:45:31 AM
Hello,

Mnats, Thanks for this drawing but unfortunatly, I just can't read it. Don't know why but the image on my computer is really blurry... :?

Neeno told radiance he was going to redraw it's wiring and I was also waiting for this.

Thanks a lot for your help
Title: 1176LN Rev D DIY
Post by: Neeno on January 12, 2008, 07:45:44 AM
Ok guys... sorry but i was pretty busy... we had 60cm snow this night...
I love this country ! ahahah

This should work, it's the way i connected my t-attenuator...
(http://www.studio21.ch/diy/neeno/1176%20t-attenuator.JPG)

Check it, try it and post back please !
Cheers
Title: 1176LN Rev D DIY
Post by: radiance on January 12, 2008, 08:31:43 AM
Neeno,  that is exactly what I made of the pic Mnats posted and it works  :grin:
Title: 1176LN Rev D DIY
Post by: Neeno on January 12, 2008, 09:25:48 AM
That's great !  :thumb:
Thank you !!!  :grin:
Title: 1176LN Rev D DIY
Post by: tommypiper on January 12, 2008, 04:43:34 PM
Just wanted to offer a quick update.  Underthebigtree got his working on New Year's Eve when we did a systematic check and diagnosis.  (We found nothing wrong after he had already sorted some grounding.)  He ran some drum mixes through it.  It Sounds Great.  I'm sure he'll post when he gets time.  

Meanwhile, I'm still wiring mine during rare kid-free moments...  Was doing some unusual configurations which puzzled me for a while.  H pad instead of T pad.  Stereo in one box with one meter.  Figuring out stereo link options, different PSU options, different Lundahl iron, Neve iron, etc... more later.
Title: 1176LN Rev D DIY
Post by: Nadege on January 16, 2008, 11:56:43 AM
hELLO

I've been working ahrd these last days to finish a dual 1176 Rev D using Mnats PCB and ed's transformers (altran input and cinemag output)

Got one channel working fine but not the other one.

I've been thru all the usual test, bring in my oscilloscope and found something quite strange...

When I'm applying a sine (1.000kHz) to both input and tracing the signal, I have exactlt the same signal up to the input of the altran (changing with my input PEC bridged T attenuator position. BUT after the altran , the signal is 2 time softer on the "non working properly" channel.

Is it possible I solder the altran the wrong way? I put both of them with the sticker facing the same point . Is it possible the sticker on one of the transformer was sticked at the wrong place ??? :?  :?  :?  :?

The problem is there, but Im a bit lost...

any idea

I'll try to post pictures asap

Thanks :sad:
Title: 1176LN Rev D DIY
Post by: Nadege on January 21, 2008, 06:53:43 AM
hello

I've wired the altran the other way and it seems to be ok now.. Still have a burned transistor on the output stage to fix.
Title: 1176LN Rev D DIY
Post by: Miska on March 03, 2008, 09:33:44 AM
Hello!

I'm soon going to start building a dual version of the rev D.
I'd like to know how many of you built this in 1RU rack case? Or was it only Mnats himself who did it? Did you meet any issues afterwards that were caused by the 1RU installation? Hum, noise etc.. Would you recommend building in 1RU or not?

Let me know your opinions!

Thank you,
Miska
Title: 1176LN Rev D DIY
Post by: kato on March 03, 2008, 10:29:00 AM
The VU meters are the biggest issue.

If you can find VU meters that fit in a 1U case, and don't mind removing the endbells from the output transformer - you can fit it in 1U.

You'll make life a little easier for yourself if you use 2U. :)
Title: 1176LN Rev D DIY
Post by: Nele on March 03, 2008, 01:31:10 PM
Any chance of a new pcb-run?

cheers,
c
Title: 1176LN Rev D DIY
Post by: buschfsu on March 03, 2008, 02:47:15 PM
also interested in a run...

just finished a rev g and would like to start a rev d

thanks
Title: 1176LN Rev D DIY
Post by: mnats on March 03, 2008, 03:00:11 PM
I've been busy with other things lately, but I intend to do another batch.

While I was building mine I made the following list of changes I intend to make on the original Rev D files:

Fix ground plane shorts on Q7 - Q10
Make C2 and C11 0.2" pitch
C18 Pitch narrower
More room for Q6
Ground near Pad 7 to aid proper wiring
Larger holes/pads for power in
Place for shorting pins for R44 to assist calibration
Correct value of emitter resistor Q3

If there are any other suggestions please post them here, particularly if you have built one and had any issues not covered by the above.
Title: 1176LN Rev D DIY
Post by: radiance on March 03, 2008, 03:08:26 PM
Quote from: "mnats"
I
Larger holes/pads for power in
.


Maybe larger holes for all screw terminals...

I drilled mine larger and thus disconnected the lower groundplane from the upper one. Easy to fix but still...
Title: 1176LN Rev D DIY
Post by: Nele on March 03, 2008, 03:53:06 PM
Quote from: "mnats"
I've been busy with other things lately, but I intend to do another batch.


Ok, cool!
Looking forward to building a stereo unit.
Title: 1176LN Rev D DIY
Post by: Skylar on March 04, 2008, 01:17:38 AM
Quote from: "mnats"
Correct value of emitter resistor Q3


Hmmm, what's wrong with this? The Q3 emitter resistor (R11) should be 82ohms according to the schematic, which is also what your boards say.
Title: 1176LN Rev D DIY
Post by: mnats on March 04, 2008, 10:26:45 AM
Just finished all the modifications I outlined above plus radiance's request - all the pads for external wiring are now 50 mil (1.2mm) rather than 40. Also gave the last stage of the line amp its own ground path. Checked each net - all lookin' good though it's nearly 2AM and I'd better get some rest before getting up at 6 to head to work :evil:
Title: 1176LN Rev D DIY
Post by: radiance on March 04, 2008, 10:36:59 AM
:thumb:
Title: 1176LN Rev D DIY
Post by: Nele on March 04, 2008, 10:47:04 AM
excellent!

 :guinness:  :guinness:
Title: RevD
Post by: nielsk on March 07, 2008, 10:16:31 PM
I am just finnishing stuffing my boards (finaly) and would greatly appreciate some steering on the problem fixes that you mention, how do I fix the ground plane short on Q7-10? with the black boards, it is very difficult to see (please save me from reading 30 pages to find this!) I also can find no problem with the resistor mentioned....
BTW, count me in for some more bords when you make them!

Thanks
Title: 1176LN Rev D DIY
Post by: kazper on March 08, 2008, 02:05:37 AM
Page 9 there nielsk...
Title: 1176LN Rev D DIY
Post by: nielsk on March 08, 2008, 06:52:39 PM
got it, thanks
Title: Board layout improvements
Post by: nielsk on March 09, 2008, 09:27:32 AM
How about adding the extra pad for the use of 2n5088s on Q5, 12 & 13?
Title: Re: Board layout improvements
Post by: mnats on March 10, 2008, 04:34:10 PM
Quote from: "nielsk"
How about adding the extra pad for the use of 2n5088s on Q5, 12 & 13?

Nice one. Done.

BTW the ground plane short fix post is linked directly from my Rev D site as always.

Regarding the resistor value correction think series resistance. Never mentioned R11 myself...

At some point I'll stop fiddling with it and send the files off, but I might wait a week to see if there are any more ideas for improving the original Rev D boards that haven't been covered yet. Thanks for the ideas so far.
Title: 1176LN Rev D DIY
Post by: Skylar on March 11, 2008, 03:00:55 PM
doh!
Series resistance on the Q3 emitter...

Rev D has 992R (82R + 910R) whereas Rev F has 1.882K (82R + 1.8K) resistance at this point in the circuit.

Thank you.
Title: 1176LN Rev D DIY
Post by: mnats on March 17, 2008, 07:20:01 AM
I'm going to send off the files to the fab before I go on a short break. Here are the things I've changed from the original PCB...

Quote
Rev D Version 2 changes:

Fixed ground plane shorts on Q7 - Q10

Added alternate pads for Q5, Q12, and Q13 so 2N5088s can be used in these positions too (like the Purple MC76)

Made C2 and C11 0.2" pitch rather than 0.1"

C18 Pitch narrower for better fit

More room for Q6 + heat sink

Ground pad near Pad 7 to aid proper wiring

All pads for external wiring changed to 50 mil holes

AC IN pads larger

Place for shorting pins for R44 to assist calibration and room for three pin header to hold shorting plug

Correct value of resistor R12

Power supply has its own ground plane

Final stage of line amp has its own ground path

Should have boards in a couple of weeks, then a few more weeks to test one before offering them at the Black Market and posting self-etch files.
Title: 1176LN Rev D DIY
Post by: David Kulka on March 25, 2008, 10:25:38 PM
I was working on some 1176LN Rev D's with meter issues and a web search led me to this thread.  (Actually, the thread helped me to work out my procedure.)  Regarding R44 and the meter calibration steps, here's how I align this circuit on Rev D's.  I don't add trimpots to original units but you can bypass the last step by using a 10k trimpot for R44.  The FET is critical.

Let the unit warm up for at least a half hour.  After setting the Q1 bias and verifying that audio limiting is working ok, measure the output level with an external meter, select GR metering, and select 20:1 ratio.  Connect a 10K pot or a resistor sub box, set to 3K, to the Q12 and Q13 emitters (R44 pads, with no R44 connected yet).  Apply a 1K sine wave to the input (+4 is fine but input level is not critical) and adjust the input and output controls so that when you turn the attack on, output level decreases by 10 db.

Turn attack off.  Connect a DVM (range of 2-5 VDC is good) to R74.  Adjust R75 (Null) for zero volts.  Adjust R71 (GR zero) for zero on the VU meter.  The adjustments interact so you might have to repeat them 2 or 3 times.

After that is done, turn the attack switch back on.  The GR meter reading should go down.  Change the setting on the test pot or sub box to achieve a reading of -10 on the VU meter.  Double check your external meter to be sure you still have a 10 db change.  Toggle the attack switch on/off a few times to verify zero and -10 on the meter.  (With attack and release set to fast this part will be quicker.)

Turn off the attack, and re-check the voltage across R75.  If it's not zero, re tune the trimmers as needed.  Check R44 again, you may have to adjust it one more time for an exact 10 db change.

Disconnect the pot or sub box and check the resistance.  If using a test pot, you'll use your DVM to carefully measure it's resistance at that setting.  Choose a resistor or (if you don't have a Wall Of Resistance like the one on our web site http://studioelectronics.biz/MeetTheShop8-13.html) combine resistors to match the value that you measured.  Temp in the resistor(s) and if you still have -10 on the meter, solder it in and you are done.

Quote from: "ap123"
Upon actually following the calibration procedures outlined in the urei docs I encountered a never-ending circle of confusion.  For instance, the more I tinker I realize that the procedure outlined in 5.3.2 is sort of dependent on that of 5.3.3 and so on.

Does the procedure to adjust the null and tracking require the complete removal of R44?  On page 60 of the urei pdf, there is a document entitled "Meter Calibration" the relationship between R75, R71, and R44...that is a sensitive dynamic that one there, especially when you throw the R44 as a trim pot into the mix.

Also, I read in the G thread that shorting terminal 22 to ground is the same as placing attack in the off position (as mentioned numerous times in the docs).  Does this apply to the rev D board?

Can the bias adjustment be made with the meter trim pots whacked out (or centered, say)?  

I need to finish reading the rev G thread one of these days...sorry.
Title: 1176LN Rev D DIY
Post by: mnats on March 29, 2008, 06:02:31 AM
Wow, thanks for the post, David!

A small error cropped up on my new PCBs so they'll be delayed. I'll post @ the Black Market when they are ready.
Title: rev d's
Post by: nielsk on March 29, 2008, 08:58:28 AM
please plan on at least 4 for me!

thanks
Title: 1176LN Rev D DIY
Post by: buschfsu on April 06, 2008, 12:43:56 AM
im in for at least one any idea when a batch would be run?
Title: 1176LN Rev D DIY
Post by: mnats on April 07, 2008, 03:51:28 AM
Quote from: "buschfsu"
im in for at least one any idea when a batch would be run?

Well, like I wrote four posts ago I sent off files on the 17th of March. I posted again on the 29th saying there was a small error. The corrections were made on the 2nd of April so the boards should be finished in 7 working days and in my hands the following week.
Title: 1176LN Rev D DIY
Post by: buschfsu on April 07, 2008, 12:08:46 PM
:oops:
Title: 1176LN Rev D DIY
Post by: vertiges on April 07, 2008, 01:26:30 PM
I'm in for at least one too...  :wink:

Thanks Mnats,

eD
Title: 1176LN Rev D DIY
Post by: ask on April 07, 2008, 02:46:30 PM
I'd very much like two boards!!!  :thumb:
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2008, 02:22:08 PM
That's awesome your making another run. I use mine to death lol.

Is there going to be another transformer run? If so I am definitely in for a set.
Title: 1176LN Rev D DIY
Post by: buschfsu on April 08, 2008, 03:18:11 PM
Quote from: "Neeno"
Ok guys... sorry but i was pretty busy... we had 60cm snow this night...
I love this country ! ahahah

This should work, it's the way i connected my t-attenuator...
(http://www.studio21.ch/diy/neeno/1176%20t-attenuator.JPG)

Check it, try it and post back please !
Cheers


looking to prep this before the boards arrive.  these values are dual gang 10k log taper and 2x 600ohm resistors correct?  anyone have a part number for the dual audio pot?  might be hard to source.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 08, 2008, 06:27:57 PM
The schematic for the T-Pad is here on the bottom page:

http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf
Title: Finally!
Post by: Skylar on April 08, 2008, 11:22:12 PM
Here's my Rev D.
I spent about a year leisurely acquiring the parts.
I had a ground loop issue that was causing serious grief, but once I cleared that up, this unit calibrated with ease.
The result, as many have attested, is aurally outstanding!

Here is a HUGE thanks to mnats, edanderson, ap123, kato, sintech, and everyone else involved in this thread.


(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front01s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front01.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front02s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front02.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front03s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front03.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front04s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front04.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front05s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front05.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front06s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front06.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front07s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_front07.jpg)

So, the wiring could be more tidy, but oh well...it works!

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts01s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts01.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts02s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts02.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts03s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts03.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts04s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts04.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts05s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_guts05.jpg)

(http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_rear01s.jpg) (http://i73.photobucket.com/albums/i222/skylargray/SCA/1176revD/1176d_rear01.jpg)
Title: 1176LN Rev D DIY
Post by: vertiges on April 08, 2008, 11:57:05 PM
:thumb:  :thumb:  :thumb:

I love the input and the output knobs !!!

eD)))
Title: 1176LN Rev D DIY
Post by: Hairball Audio on April 09, 2008, 01:22:56 AM
Awesome work Skylar!

How did you mount the pushbutton PCB's to the enclosure?  I see bolts going to the front panel but clearly the bolts don't travel through to the front.

Mike
Title: 1176LN Rev D DIY
Post by: mnats on April 09, 2008, 04:15:04 AM
That's a beautiful build, Skylar, and it looks as though you mostly have yourself to thank. The boards are probably less than 10% by weight. :wink:
Quote from: "buschfsu"
these values are dual gang 10k log taper and 2x 600ohm resistors correct?

I thought our earlier exchange might have been a hint, but I'll just say it - you might want to spend more time reading and less time posting. It is not a dual gang 10k log taper at all.

Though my Rev D page is far from complete and contains a few errors, the linked threads including the one about the T attenuator should have enough information to point you in the right direction. As always, the page is linked from the first post of this thread.
Title: 1176LN Rev D DIY
Post by: buschfsu on April 09, 2008, 09:14:35 AM
i don't mean to clog the board but some of this stuff is not all that clear.

nydave said "The short story is, you can't do it with an off-the-shelf pot."

and neno's diagram that you point to has no values listed.  nor does the BOM.  

just a little confused (not so much lazy)
Title: 1176LN Rev D DIY
Post by: Stagefright13 on April 09, 2008, 09:25:16 AM
A Mallory 600 ohm t-pad pot works fine. They come up on ebay sometimes.

And Skylar that looks like a fine piece congrats!!
Title: 1176LN Rev D DIY
Post by: edanderson on April 09, 2008, 10:13:52 AM
the short answer is that to duplicate the original front end of the class A 1176, you need a special type of pot called a t-pad attenuator.  there are a few different types, made by a few different companies, some surplus, some new.  there is nothing you can order from the usual digikey/mouser type places that will work.  this thread and the mnats 1176 pages have a lot of good info about what is available and from whence.

ed
Title: 1176LN Rev D DIY
Post by: Skylar on April 09, 2008, 12:37:10 PM
Echo,

RE: pushbutton mounting

The back of the 4mm front panel is tapped with 2.5mm deep 4-40 blind holes.
I took careful measurements for this section of the front panel so that everything would line up.
Title: 1176LN Rev D DIY
Post by: Hairball Audio on April 09, 2008, 12:42:40 PM
Ahhh very nice.

Thank you for the info.

Mike
Title: 1176LN Rev D DIY
Post by: Skylar on April 09, 2008, 11:24:54 PM
Almost forgot...here is a wiring diagram I used as a guide while building my unit.

This diagram reflects how I have my unit wired currently.

Note that this guide is for Altran input, PEC T-Pad, mnats pushbutton boards, Cinemag output, fused IEC power inlet, and 120V AC mains.

Also, all points where the chassis ground symbol appears are connected at the same chassis ground spot: the input XLR pin 1.

I have broken up the master diagram into several (more digestible) chunks in pdf format.

EDIT: fixed the link, combined to one pdf

http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALL.pdf (http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALL.pdf)

NEW version with input wiring fixed:

http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv2.pdf (http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv2.pdf)

http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv3.pdf (http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv3.pdf)

EDIT: diagram sent to GroupDIY gmail account (https://mail.google.com/mail/?ui=2&ik=ba1fdd4343&view=gvatt&th=126e307e7ec53667&attid=0.1&disp=attd&mime=application%2Fpdf&zw).
Title: 1176LN Rev D DIY
Post by: Vas on April 10, 2008, 09:54:04 PM
SKYLAR!GREAT BUILT!where did you find those IN/OUT knobs?
Title: 1176LN Rev D DIY
Post by: Skylar on April 11, 2008, 12:24:28 AM
The input/output knobs are General Radio KNSP6 I believe.

I got them from a local surplus store.

Old General Radio gear had THE best knobs. period.

(http://www.wfp76364.w1.com/GENERAL_RADIO_1432-A_DECADE_RESISTOR_WITH_TEXT_B5_N1.jpg)


(http://i234.photobucket.com/albums/ee59/retrorabbitphotos/variac2.jpg)
Hmmmm, and where do we recognize these knobs from?




(http://www.mixmasters.com.au/used/photos/WEB%20BIG/fair_1.jpg)
Title: 1176LN Rev D DIY
Post by: mnats on April 23, 2008, 03:42:13 AM
I've received a few PMs about the latest batch of boards for this project. Not sure why no one just posts their questions here as there isn't anything secret about it and I don't intend to show any favoritism toward any particular person or group. I also don't intend to answer any PMs about the board order - I simply don't have the time to have one on one communication about them but I'm very happy to discuss it publicaly.

So here's the update: the boards are late arriving. The factory hasn't been very good at communicating with me but it's hard to get upset since they caught what could have been a fatal error (well, not exactly fatal...) so I'm giving them the benefit of the doubt.

I will have to check the boards (read: build one) before offering them for sale and posting the self-etch files. I was hoping to do this during the school break but who knows what will happen until I hear from the factory. The email went out today so hopefully they will get back to me soon.

Once they arrive I'll get onto stuffing the board and dropping it into my already-built dualie (http://www.groupdiy.com/index.php?topic=22788). If they work as advertised, I'll make a post on the Black Market.

That's the scoop - please feel free to ask any questions right here. But please, let's not turn this into a "I want two sets of boards" thread. I will post in the Black Market when the time comes.

______________________________________

Latest news: The boards shipped today so I should have them by early next week. That should give me enough time to stuff one board before school starts again...
Title: 1176LN Rev D DIY
Post by: sysexguy on April 24, 2008, 09:06:15 PM
I'm just about the **finally** finish up and wire my 1176"d".

I have a quick question for the experts. It seems a bit silly to bring the output all the way to the front panel right by the psu for the meter board. Wouldn't it be better to place a relay right between the output tranny and the output xlr, place the meter board somewhere near the output xlr and have the front panel actuate the relay as required for the meter function? In that way, when the meter is bypassed, the signal path would be optimized.

Thanks in advance, I'm quite excited :twisted:

Andy
Title: 1176LN Rev D DIY
Post by: guavatone on April 25, 2008, 03:31:15 AM
Slick build

 :guinness:  :guinness:  :guinness:
Title: 1176LN Rev D DIY
Post by: mnats on April 25, 2008, 05:44:29 AM
Quote from: "sysexguy"
I have a quick question for the experts. It seems a bit silly to bring the output all the way to the front panel right by the psu for the meter board. Wouldn't it be better to place a relay right between the output tranny and the output xlr, place the meter board somewhere near the output xlr and have the front panel actuate the relay as required for the meter function? In that way, when the meter is bypassed, the signal path would be optimized.

I'm not an expert, but I am the idiot who designed these boards. I've never used the rotary switch boards - which are basically copies from Jakob's G1176 - for any of my completed builds. But I did note while laying them out that they, like the original, remove the meter from the signal path completely when switched out.

So unless I've missed something I don't see a reason for concern.
Title: 1176LN Rev D DIY
Post by: mnats on April 28, 2008, 07:25:32 AM
New boards arrived today - looking good. I'll be stuffing one over the coming week.
Title: 1176LN Rev D DIY
Post by: Vas on April 28, 2008, 08:05:34 AM
GREAT!i can't wait!will you open a thread at black market?
BEST REGARDS
BILL
Title: 1176LN Rev D DIY
Post by: mnats on April 28, 2008, 08:44:21 PM
Quote from: "Vas"
will you open a thread at black market?

Quote from: "mnats"
Once they arrive I'll get onto stuffing the board and dropping it into my already-built dualie (http://www.groupdiy.com/index.php?topic=22788). If they work as advertised, I'll make a post on the Black Market.

That's the scoop - please feel free to ask any questions right here. But please, let's not turn this into a "I want two sets of boards" thread. I will post in the Black Market when the time comes.

I'd love to finish building and testing the boards and would rather not spend my time answering questions that I only answered a few posts ago...
Title: 1176LN Rev D DIY
Post by: mnats on April 29, 2008, 08:54:02 AM
(http://www.geocities.com/m_natsume/images/1176_rev_d_version_2_close_small.jpg) (http://www.geocities.com/m_natsume/images/1176_rev_d_version_2_close.jpg)
(http://www.geocities.com/m_natsume/images/1176_rev_d_version_2_test_small.jpg) (http://www.geocities.com/m_natsume/images/1176_rev_d_version_2_test.jpg)
Sorry for the sh*te pictures. 1st boards stuffed and calibrated...tests OK. Will post again soon...
Title: 1176LN Rev D DIY
Post by: mnats on May 01, 2008, 04:00:13 AM
Ok, boards on offer @  the Black Market (http://www.groupdiy.com/index.php?topic=330976). PDF file for self-etch here (http://www.geocities.com/m_natsume/files/DIY1176LNREVD_V2.pdf).
Title: 1176LN Rev D DIY
Post by: okgb on May 03, 2008, 07:43:21 AM
I know it's subjective , and you've listed the  " refinements " for your
latest D pcb over the previous version but i have a pair of D boards from
 your last batch and am considering getting this newer version instead ?
 
 Nothing wrong with the last version  but you took the opportunity
to make a couple tweaks since a new batch was coming ? Does this
latest version make the build much easier or as i guess really things
i should assess for my particular case . How much happier were you
with it ?

Thanks again for making a fine board available
[ i'm getting to mine ..........really ! ]

tia regards Greg
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 03, 2008, 11:06:48 PM
Come on Greg you didn't build yours yet? Slap! Just kidding.

It don't think it will be easier to build. The jumpers are nice for calibration tho. But on my original board I put a socket in to remove the trimmer for calibration.
Title: 1176LN Rev D DIY
Post by: Stagefright13 on May 04, 2008, 12:33:41 AM
Andy the front panel shouldn't be any where near the psu. At least in a single channel one. I used shielded cable for everything lol. If in doubt shield it! Mine is whisper quiet.
Title: 1176LN Rev D DIY
Post by: sysexguy on May 04, 2008, 06:43:25 AM
Hi John, Mnats, thanks for the advice, hopefully my next post is me  :green:

Andy
Title: 1176LN Rev D DIY
Post by: mnats on May 05, 2008, 03:51:00 AM
Quote from: "okgb"
I know it's subjective , and you've listed the  " refinements " for your
latest D pcb over the previous version but i have a pair of D boards from
 your last batch and am considering getting this newer version instead ?
...
Thanks again for making a fine board available
[ i'm getting to mine ..........really ! ]

As I mentioned to you in reply to your PM about the boards I feel like I've been upfront about both versions. The self-etch files of both versions with overlay, top and bottom layers are still up on my Rev D site (http://www.geocities.com/m_natsume/1176_revision_d.html) and I've linked to the post outlining the changes to the new batch in my board sales post (http://www.groupdiy.com/index.php?topic=27554). I don't really think it's up to me to decide which boards you should have.

I will say, though, that I'm not really interested in selling PCBs to those who are just collecting boards for "someday" but would rather see them go to active builders. It always make the effort worth it to me when I see people post their finished builds and tell me that they use them all the time!

Each board has the same number of components and describes exactly the same circuit so neither one is "easier" to build than the other. As Stagefright13 mentioned, the jumpers for the meter calibration make aligning the unit a bit easier, but it's not exactly a huge milestone. Where there were things I thought I could do better, I tried.
 
Quote from: "okgb"
Nothing wrong with the last version  but you took the opportunity
to make a couple tweaks since a new batch was coming ? Does this
latest version make the build much easier or as i guess really things
i should assess for my particular case . How much happier were you
with it ?

BTW, there was an issue with the earlier boards, also well documented, but I corrected each one that was sent out after the fault was discovered. And yes, I'm happier with the new boards because I don't have to fix each one that goes out...
Title: 1176LN Rev D DIY
Post by: mitsos on May 05, 2008, 12:02:05 PM
hey all,

back to the attenuator question...  I found an old 500 Ohm T attenuator in my pile-o-junk... Would this work, just not "attenuate" as much as the 600 Ohm?   I guess as soon as I have all the rest of the parts I'll give it a shot anyway, since I am having trouble finding a 600 Ohm.. But wanted to hear from you all if this would NOT work for any reason not so obvious to my noob mind.
thanks...
Title: 1176LN Rev D DIY
Post by: okgb on May 05, 2008, 12:08:19 PM
No Problem , you've gone more than the distance with these
so thanks anyway . Thanks for letting us know how you feel .

 btw i'm not collecting boards , it's just that it's a serious investment ,
in for a penny  , in for a pound  , I'd like them to be as good as possible
and hence part of the question to you  [ and pm'ing was trying not to
make a big deal of it  ]  so if i can make it better , why not ?

So here's my stuffed boards and parts in the cue
(http://i83.photobucket.com/albums/j319/okgb/Picture079.jpg)
(http://i83.photobucket.com/albums/j319/okgb/Picture080.jpg)

they're no good if you can't use em , so pitter patter i gotta get at er

regards Greg




 
Now if we could only save the world with better compression
Title: 1176LN Rev D DIY
Post by: jpuhhuh on May 05, 2008, 07:32:50 PM
Hey Greg,
I like your panel layout. You can tell you use think like you are going to use it. If I may ask where you did it?
Nicely done.
JP
Title: 1176LN Rev D DIY
Post by: okgb on May 05, 2008, 11:21:17 PM
A fellow lab member made them in exchange for pcbs ,
but i am working a library of designs that you can take to
the average trophy engraver and get done ,
there's one on Mcphillips and another on St James ,
i can email some IF i have what you are looking for .

regards Greg
Title: 1176LN Rev D DIY
Post by: Vas on May 06, 2008, 05:17:16 AM
hi everyone!i would like to know if there are any pec or other 600Ω ATTENUATORS available or if a group buy is going to take placeas long as a new batch of pcbs are available?
a part # or any other information would help!
best regards
bill
Title: 1176LN Rev D DIY
Post by: electrochronic on May 09, 2008, 07:55:18 PM
Vas,


some group action might be good
Count me in as well, I'll be needing 2 PEC T600 Attenuators
Title: 1176LN Rev D DIY
Post by: dissonantstring on May 09, 2008, 08:11:43 PM
hi guys,
here's what ed anderson says earlier in the thread:

Quote from: "edanderson"

PEC in canada makes a reasonable facsimile of the two deck bridged-T attenuator, and supplies them to UA.  i think i heard about someone getting one from UA for ~$50?  but then i believe the same person said it was scratchy after six months.  i got a quote from precisionsales.com and the 50 pcs price was $35ea.  the part number is 05-0007 if anyone wants to go that route.  you are unlikely to find anyone else willing to make the unusual tapers that are required for this part.
ed


just FYI.
Title: 1176LN Rev D DIY
Post by: Vas on May 09, 2008, 08:13:22 PM
hi maxwall!

i think that it would be better a member from canada/u.s.  should organize a group buy as long as PEC is in canada,actually an another u.s. member here has helped me a lot to locate various 1176 project parts(knobs,pushbutton banks,caps e.t.c)so we are trying to locate a source for t-pad attenuators too!
but the think is that we do not have enough information! :?

so if anyone knows a part #,he could post it here so maybe we could organize a new groupbuy from pec!



 :!:
Title: 1176LN Rev D DIY
Post by: Vas on May 09, 2008, 08:46:20 PM
Quote from: "dissonantstring"
hi guys,
here's what ed anderson says earlier in the thread:

Quote from: "edanderson"

PEC in canada makes a reasonable facsimile of the two deck bridged-T attenuator, and supplies them to UA.  i think i heard about someone getting one from UA for ~$50?  but then i believe the same person said it was scratchy after six months.  i got a quote from precisionsales.com and the 50 pcs price was $35ea.  the part number is 05-0007 if anyone wants to go that route.  you are unlikely to find anyone else willing to make the unusual tapers that are required for this part.
ed


just FYI.

THANKS!i think i missed that  :roll:
best regards
bill
Title: 1176LN Rev D DIY
Post by: okgb on May 10, 2008, 08:29:57 AM
But if U.A. is using them ????

I can look at doing a grp buy out of Canada if there is interest ,
would have to be prepaid .

regards Greg
Title: 1176LN Rev D DIY
Post by: Vas on May 10, 2008, 09:51:19 AM
I would be in for that!
best regards
bill
Title: 1176LN Rev D DIY
Post by: Hairball Audio on May 10, 2008, 10:45:02 AM
I'd be in for 4.

Mike
Title: 1176LN Rev D DIY
Post by: Bri on May 10, 2008, 04:06:08 PM
I'd definitely be in for one.

--Brian
Title: 1176LN Rev D DIY
Post by: electrochronic on May 10, 2008, 05:58:26 PM
I suppose I'd take a T-600 attenuator from either PEC or Precisionsales, makes little difference to me. But a group buy will be good in keeping the price reasonable. In the meantime, I'll build a 0-20db , 2db incremented rotary stepped attenuator like below or NYD's design to suppliment the immediate need, until I get my pinchers on the T600 real non-rotary t-attenuator.
(http://img.photobucket.com/albums/v611/maxwall/1176Trotary.jpg)
(http://img.photobucket.com/albums/v611/maxwall/600bridgedt.gif)
Leeds radio supply has only one Mallory T600 3 deck left for $53 , so that source is now dry.

I'm having trouble reading pages 41-42 of the 1176 Manual found at

http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf

, are they even relavent to the build,  I wonder ?

***
Title: 1176LN Rev D DIY
Post by: Hairball Audio on May 10, 2008, 06:11:16 PM
I emailed Leeds yesterday as well!  I decided not to pick up his last T600.  I need two anyway.

I recall reading that some builders did not like their feel.  Keith maybe?

Thinking about trying to make my own as well.

Mike
Title: 1176LN Rev D DIY
Post by: EmRR on May 10, 2008, 06:44:20 PM
I bought a lot (30?) of the Leeds NOS Mallory (EDIT!! CLAROSTAT!!!) T's many years ago, and 3/4 of them were bad.   Leeds refunded me, no problem.  They have a riveted piece that locks the decks together that seems to have broken loose on most of them.  The ones that work tend to be noisy when rotated, being wirewound.  I wouldn't consider that type to be first choice.

Manley uses some variety in the Vari-Mu limiter; might be worth checking their source/price.
Title: 1176LN Rev D DIY
Post by: electrochronic on May 10, 2008, 06:59:07 PM
Doug,

Thanks for the prosumer awareness alert on the mallory types.
will be steering clear of those in the future.

was the loose rivet causing contact issues due to the inceased play inside
the attenuator housings ?
Title: 1176LN Rev D DIY
Post by: ruairioflaherty on May 10, 2008, 07:37:41 PM
FYI I bought two of the Mallorys from Leeds the last time I was in New York.  The NOS and the plastic bags inside were sealed.  I haven't used them yet as I'm still slowly gathering the key parts for an authentic rev D but I can say that the feel is a little rough but not such that it would concern me.  They are also a lot bulkier than the newer alternatives but that shouldn't concern us because of the neatness of Mnats pcb (good job!).

I'm hoping that these are a different batch to the ones Doug had trouble with, I bought 'em last July.  I'd be in for 5 of the PEC or precision sales versions if anyone has the patience to organise a group buy.  I'd gladly step up but my location rules it out.

I've got the O12s, Modutecs, 600 Ohm attenuators and pcbs for 2 builds - working on a local parts lists, getting excited now.

Cheers,
Ruairi
Title: 1176LN Rev D DIY
Post by: nielsk on May 10, 2008, 09:01:19 PM
The 3 deck units from State as used by Purple (they used the original version in early units, wound up having to change them all out as they went scratchy) work great, very smooth. Why would you want to use anything else?
Title: 1176LN Rev D DIY
Post by: EmRR on May 11, 2008, 11:27:43 AM
Quote from: "maxwall"
Doug,

Thanks for the prosumer awareness alert on the mallory types.
will be steering clear of those in the future.

was the loose rivet causing contact issues due to the inceased play inside
the attenuator housings ?


The Clarostat decks were amputated from one another, or so loose that end travel caused circuit disconnect.   The shaft does not go through all three decks.  The riveted piece is the 'hand' holding two shafts together.  EDIT: pics posted on the next page.

At the time, I attributed the deaths to poor storage; box of loose pots all crushing one another, possibly also dropped in shipping.  At any rate, it's a part that will wear out in use, and wire-wound scratches when turned so you don't adjust in use.
Title: 1176LN Rev D DIY
Post by: mitsos on May 12, 2008, 03:31:10 PM
I'd also be in for 2 attenuators if this group buy happens...
It's the missing link for me, (as long as I can get my hands on o/t from Ed!)

Thanks Maxwall for posting the switch diagrams...
Title: 1176LN Rev D DIY
Post by: Hairball Audio on May 12, 2008, 05:06:34 PM
Hi Maxwell,

Do you have a good source for 2-pole 12-pos (MBB) switches for home made t-pads?  Lorlin doesn't seem to make 2-pole 12-pos and digi and mouser came up dry.  There is this Grayhill...but it's a 2 pole 2 deck 6 position...which I assume is different then 2 pole 12 position.  They also have a 1 pole 12 position 2 deck model.

Frankly I'm done with the T-pad attenuator search.  If I can make a switch that will do the same thing that's fine with me! :)

For anyone who cares, I spoke with precisiosales this morning:
Bridged attenuator model 05-0007 600ohm  
US$38.90
25 Min Order.

I WILL NOT BE MAKING THIS ORDER.  This is just for those interested in starting a group buy.

-Mike
Title: 1176LN Rev D DIY
Post by: dissonantstring on May 12, 2008, 07:52:12 PM
mike,
mouser does have a 2 pole / 12 position rotary (MMB-shorting).
mouser #: 105-SR2921F-12S
it has two wafers and 1 pole / 12 positions per layer.  i've used them before on my 1272 Hot Rod with greg's pcbs.  

they are cheap and feel pretty good, the catch...they don't have any end stops.  but in the LAB you know someone's figured this one out right?  Thank you to NYDave in this thread (http://www.groupdiy.com/FORUM/viewtopic.php?t=11951&highlight=adding+end+stop+rotary+switch&sid=ca7e79cc9f643789fd953a77f68ae3cc)
hope this helps!
-grant
Title: 1176LN Rev D DIY
Post by: Hairball Audio on May 12, 2008, 08:33:18 PM
Oh that is perfect!

I missed that NYDave thread in my searches.  I did see his thread on resistor values.

Thanks a ton Grant!

This is definitely the route I am going to take.

Mike
Title: 1176LN Rev D DIY
Post by: electrochronic on May 12, 2008, 09:24:21 PM
Grant , Mike

the Alpha 105-SR2921F-12S ,  a DIY favorite.

I'm thinking of groupbuy on the Bridged attenuator model 05-0007 600ohm

Does anyone know if EdAnderson has this covered ?
Title: 1176LN Rev D DIY
Post by: edanderson on May 12, 2008, 09:33:05 PM
Quote from: "maxwall"
Does anyone know if EdAnderson has this covered


ooh ooh, i know.

no.  i will not be buying any PEC attenuators.

ed
Title: 1176LN Rev D DIY
Post by: electrochronic on May 12, 2008, 09:37:49 PM
Ed ,

what a laugh.. did'nt expect that reply.

Ok maybe I'll start the T attrenuator group buy ?

As you know, Were all anxious for your transformers now.
Title: 1176LN Rev D DIY
Post by: edanderson on May 12, 2008, 09:43:40 PM
Quote from: "nielsk"
The 3 deck units from State as used by Purple (they used the original version in early units, wound up having to change them all out as they went scratchy) work great, very smooth. Why would you want to use anything else?


this is not quite right.  the original 2 deck attenuators from clarostat were fine, they worked forever and we even used old surplus NOS units.  when they were discontinued, andrew started using the 3 deck modpot from state.  years later, when we looked at the PEC 2 deck attenuators, we heard from some UA users that they went scratchy; the sample we had seemed okay at first.

anyway, the 3 deck attenuators from state are very likely to be considerably more expensive than the PEC 2 deck attenuators.  but they do work well, which is why purple continues to use them.

ed
Title: 1176LN Rev D DIY
Post by: electrochronic on May 12, 2008, 09:59:38 PM
Just send a quote request to state for quantity pricing for potential group order.
Title: 1176LN Rev D DIY
Post by: Vas on May 12, 2008, 10:15:37 PM
GREAT!i'm in for 2 pec or states attenuators!
best regards
Title: 1176LN Rev D DIY
Post by: electrochronic on May 13, 2008, 11:26:17 AM
Can we get a consensus on which T-Attenuator is needed ?

State is currently out of stock on the attenuators with a 4-6 week lead time.

If source-ing another brand is preferred then state will locate it and get pricing.
That is if Mallory is not the preferred manufacturer here. The goal is to locate a part that will give long hassle free lifespan.

Here is a spec sheet for a  three deck. Unfortunately these are Mallory which I
hope do not have the rivet coming loose issue as described by Doug Williams in a earlier posting.

Additionally I 'm checking on a two deck attenuator with State

(http://img.photobucket.com/albums/v611/maxwall/Tpads.jpg)
Title: 1176LN Rev D DIY
Post by: EmRR on May 13, 2008, 02:01:12 PM
Sorry folks, I was passing bad info and I've corrected the previous posts.   Too much stuff on the shelves, too few brain cells.   I had mentioned having issues with the Mallory types from Leeds, and it was actually the Clarostat types that have the riveted shaft part issue.   I have used the Mallory types as used pieces and not been terribly impressed with them, I have not used new Mallory pieces.  Sorry for the confusion.
Title: 1176LN Rev D DIY
Post by: ruairioflaherty on May 13, 2008, 02:40:32 PM
Quote from: "maxwall"


State is currently out of stock on the attenuators with a 4-6 week lead time.


4 to 6 weeks does not seem too bad to me.  Can everyone honestly say they'll have all of the other details on their Rev Ds finished in 6 weeks?  :grin:

Did you get pricing info Maxwall?  Also does anyone know the lead time on the PEC part?

As I mentioned before I have some of the NOS Mallorys from Leeds and I would rather use either the PEC or State versions.  The Mallorys are wirewound and hence have a pretty rough feel.  The main benefit of the wirewound is the higher wattage which isn't a benefit that most of us need in this context.

Cheers,
Ruairi
Title: 1176LN Rev D DIY
Post by: dissonantstring on May 13, 2008, 03:06:36 PM
hi guys,

i'm not in on this group buy, but ruairi is correct.  i'd just like to pass on my opinion having experience with the PEC, Mallory and Purple Audio (States) versions of the T600 attenuators.  

The States have the best feeling (smooth with just a touch of resistance), PEC is second best, but similar to the States, just a little less smooth and the Mallory having the least likable feel (IMHO) being wirewound it feels kind 'scratchy' not in sound, just feel.  

I can't comment on reliability as I've only had my two Rev.Ds working for less than a year.

just an opinion before you dive into a group buy of these attenuators.
regards,
grant
Title: 1176LN Rev D DIY
Post by: Hairball Audio on May 13, 2008, 03:53:24 PM
Quote from: "ruairioflaherty"
Also does anyone know the lead time on the PEC part?
Ruairi


5-6 weeks ARO

-Mike
Title: 1176LN Rev D DIY
Post by: EmRR on May 13, 2008, 07:34:47 PM
I found a dead Clarostat wirewound type I opened up, so will take and post pics of the construction soon.  It is theoretically possible to repair them I suppose, and at the going price, possibly practical to try doing so.
Title: 1176LN Rev D DIY
Post by: buschfsu on May 13, 2008, 11:36:00 PM
+1 for a group buy
Title: 1176LN Rev D DIY
Post by: electrochronic on May 14, 2008, 01:56:56 PM
We'll it looks like Nielsk has the groupbuy started in the black market. He has a State plastic element attenuator which should be affordable and appropriate for the 1176.
Title: 1176LN Rev D DIY
Post by: EmRR on May 14, 2008, 02:31:51 PM
Guts of the Clarostat type.  This was NOS from Leeds.  The small riveted piece seen between the decks ties the two 'handle bars' of the two decks together so they rotate as one. This riveted piece is broken.   The 'handle bars' slide right out, so it would be feasible to fabricate a replacement assembly and put these back together.  The two joined decks do have a joint  shaft.  

(http://farm4.static.flickr.com/3156/2492119775_64e6580b5c_o.jpg)

(http://farm3.static.flickr.com/2381/2492939824_35e1b45b25_o.jpg)
Title: 1176LN Rev D DIY
Post by: electrochronic on May 14, 2008, 08:02:17 PM
Doug,
Nice work and photo's - thanks.

Here is a diagram of a 1176 actual 2 deck T-Attenuator. I reversed an actual 1176 on the bench using an authentic unit. I traced the wiring to the block terminators from the attenuator and this is how its done. I measured both deck pots and resistors to get measured values. The second unit I tested had very different pot values (D1- CCW 265K) and (D2 -CW 25k ) I think one of them is either bad or massively out of spec. R2 and R3 actual ~ 620 ohm.

Strange, I thought the two deck pots would be 1K each, quite surprised compared to the three deck attenuator. The dual ganged pot has one CCW (rev log) and one CW (log) pot ganged together. Their AB brand J type pots.

I'm hoping someone here might know the actual pot values. The 1176 manual does not give the values of R1A or R1B ( omitted !!! ).


I can supply photo's if anyone is interested.

(http://img.photobucket.com/albums/v611/maxwall/11762deckTpad.jpg)
(http://img.photobucket.com/albums/v611/maxwall/11762deckTpadsch.jpg)
(http://img.photobucket.com/albums/v611/maxwall/11762decktpadcalc.jpg)
Title: 1176LN Rev D DIY
Post by: edanderson on May 14, 2008, 11:50:28 PM
here's the deal.  the two decks are both what is sometimes called a "dB" taper, which is a very unusual type of modified log.  instead of each pot reaching 50% of the total resistance at 50% rotation like a linear, or 10% resistance at 50% rotation like a log pot, it is much less, like 2% resistance at 50% rotation.  if you take a bunch of points and plot them, what you'll see is that the value stays quite low (almost like a linear) until very near the end and then shoots up.  this is also why the end values you measure will be quite different from unit to unit.  the exact value at each end doesn't matter that much, only that it should be "alot more" than the value in the middle.

i've looked around, and i doubt you'll be able to find anyone willing to make such an oddball taper pot these days (except for PEC, who are already doing it), and certainly not in the quantities that you're looking for.  but good luck anyway; it would be great if you did find something.

ed
Title: 1176LN Rev D DIY
Post by: EmRR on May 15, 2008, 02:41:08 AM
Again, anyone know who makes 600 ohm T's for Manley?  Same suspects, or another source?
Title: 1176LN Rev D DIY
Post by: CJ on May 15, 2008, 02:49:08 AM
daven


l
Title: 1176LN Rev D DIY
Post by: Grooveteer on May 27, 2008, 12:51:18 PM
Hi Guys,

I'm having problems getting the 2N3708's.  RS does not seem to have them and the guy in my local shop said that they're no longer available  :?:

He recommened using BC550B (although they have a different pin out)

I've looked at the datasheets, but I'm such a noob...  Would BC550B be ok to use?

Thanks!

Cheers,

G.
Title: 1176LN Rev D DIY
Post by: skipwave on May 27, 2008, 04:49:08 PM
Mouser has them, but shipping is likely prohibitive.

http://www.mouser.com/Search/Refine.aspx?Ntt=610-2N3707

http://www.centralsemi.com/PDFs/products/2n3707-3711.pdf

At a glance BC550B would make a fine sub. This design is not asking very much of them, and the 3707 was probably selected for noise performance more than anything else.
Title: 1176LN Rev D DIY
Post by: Nele on May 27, 2008, 05:57:30 PM
you can get them on ebay for not that much...
Title: 1176LN Rev D DIY
Post by: mnats on May 30, 2008, 06:04:41 AM
I've posted some tests (http://www.geocities.com/m_natsume/1176_revision_d.html#transformers) that I did on the output transformer that Ed will be offering for this project on my Rev D page.

Grooveteer - have a look at the page as well to see another substitute transistor you can use instead of the 2N3707/8. Should be able to find it anywhere.
Title: 1176LN Rev D DIY
Post by: electrochronic on May 31, 2008, 11:04:59 AM
Quote
Matching Q1 and Q11 may ensure accurate tracking of the gain reduction metering circuit that reflect the actual behavior of the audio gain reduction. However, keep in mind that the meter circuit provides a visual indication of the audio signal, so accurate matching of these parts might not be essential. You may wish to select FETs for a particular threshold range.


this would be the 2N5457 fets

Is there a easy test jig for doing this , I would like I try it : how is this accomplished ?

what threshhold is best ?
Title: 1176LN Rev D DIY
Post by: mnats on May 31, 2008, 11:34:43 PM
Quote from: "maxwall"

this would be the 2N5457 fets

Is there a easy test jig for doing this , I would like I try it : how is this accomplished ?

Never had a problem calibrating the meter circuit of any of my builds and I don't recall ever matching but I do remember someone mentioning having problems with it before. There must have been a reason why I stuck it on that page...

Anyway, the search function is your friend:

http://www.groupdiy.com/index.php?topic=55736#55736

Make sure you check out PRR's comments a little further down as well. Where matching really seems to help is if you're trying to build a stereo pair. Of course you'll worry most about the pair at the inputs rather than the ones in the meter circuit.
Title: 1176LN Rev D DIY
Post by: mnats on June 07, 2008, 06:40:48 PM
I've been working on a planned series of calibration videos for this project and have posted one on my Rev D page (http://www.geocities.com/m_natsume/1176_revision_d.html#videos). Please have a look and give any comments at all.
Title: 1176LN Rev D DIY
Post by: okgb on June 07, 2008, 07:16:51 PM
like your boards , looks good
nice pacing , pleasant , straight forward
should promote confidence for those taking it on
Title: 1176LN Rev D DIY
Post by: matta on June 07, 2008, 11:47:48 PM
Quote from: "mnats"
I've been working on a planned series of calibration videos for this project and have posted one on my Rev D page (http://www.geocities.com/m_natsume/1176_revision_d.html#videos). Please have a look and give any comments at all.



What a crackingly good video! Sounds very authoritative Mako, Kudos! Greg helped me source some of the parts I need for my Rev D and I collected them yesterday, looking forward to put it together!

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: mnats on June 15, 2008, 04:53:31 PM
Thanks for the comments, guys. I've uploaded an new video after pondering the first one I posted - check the new one out if you get a chance:

http://www.geocities.com/m_natsume/1176_revision_d.html#videos

Quote from: "matta"
Sounds very authoritative Mako, Kudos!

Hopefully it is also correct!

I may post this in a new thread as I would like to get more feedback and don't want to restrict the viewing to those who are only building this project...
Title: 1176LN Rev D DIY
Post by: EmRR on June 16, 2008, 11:17:55 AM
Look great to me; seem to cover and address different issues one might second guess or misunderstand.
Title: 1176LN Rev D DIY
Post by: matta on June 27, 2008, 12:54:00 PM
Ok,

I have read EVERY single one of these pages in a 2 hours sitting...

I'm interested to know why on the REV D Meter Board there is an additional GND Pad next to PAD 22 that DOESN'T appear in the previous version of the 1176?

In the Wiring tutorials on Mako's page it shows that the SHIELD is NOT connected on the Meter and Ratio boards, ONLY on the MAIN BOARD side.

Has this changed with REV D is one SUPPOSED to now connect the GND pad to the GND next to PAD 22 on the Main Board AND the GND PAD on the Meter Board?

Also Mako, I've found an error on your REV D page in that in the listed Resistor set values the ID tags should read R42 & R43, your have 2 x R42's.

Also GREAT job on the 2nd Calibration video, very slick indeed!

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: mnats on June 27, 2008, 09:16:48 PM
Quote from: "matta"
I'm interested to know why on the REV D Meter Board there is an additional GND Pad next to PAD 22 that DOESN'T appear in the previous version of the 1176?

Because the discrete meter circuit is different from the IC version. As noted under "Wiring Details" on my Rev D page (http://www.geocities.com/m_natsume/1176_revision_d.html):
Quote from: "mnats"
Generally, wiring the Revision D is the same as wiring a rotary version of the G1176. One subtle difference is that the GR (Gain Reduction) meter setting doesn't ground one terminal of the VU meter in the discrete version as it does in the IC circuit and special rotary control PCBs have been designed with this in mind. Please refer to the original schematic if you have any doubt about the wiring.

Quote from: "matta"
In the Wiring tutorials on Mako's page it shows that the SHIELD is NOT connected on the Meter and Ratio boards, ONLY on the MAIN BOARD side.

Those tutorials refer to the G1176-type Rev F and later version with the IC meter circuit. As noted in the quote above, the original schematic - easily downloadable - is your ultimate reference. The schematic was how I designed my boards and how I wired my prototype.

When I stole Jakob's rotary design for this version I had to adapt the idea to work with the Rev D. On the Rev F and later point 28 is also ground. With the A/B/C/D/E discrete meter circuit versions point 28 connects via R79 to the +30V supply - a slight difference!

Jakob's rotary switch incorporates the "GR Disable" (called "bypass" on the G1176 front panel), S9 on the schematic, instead of locating it on a hard-to-find 25k attack pot with SPDT switch. In order to use the meter switch as a gain reduction off switch, there has to be a reference to ground so I added it on the board. There is also a handy ground pad on the main board next to pad 22.

IIRC Jakob's meter board on the G1176 does something that doesn't appear on any of the original units. When in "bypass" the meter is shorted out. This might be beneficial for transporting the unit as it will keep the meter from banging around too much. My Rev D meter boards don't have this feature as I tried to keep it as faithful to the original schematic as possible.

Quote from: "matta"
I've found an error on your REV D page in that in the listed Resistor set values the ID tags should read R42 & R43, your have 2 x R42's.

Thank you - I've corrected it.
Title: 1176LN Rev D DIY
Post by: matta on June 28, 2008, 03:24:50 AM
In the words of Napoleon Dynamite, I'm an "IDIOT!" Hah hah, how did I miss the BLEEDING obvious in your REV D page. I picked up the small resistor 'error' and somehow missed the VERY clearly instructed key piece of info RE the GR meter after reading 40+ pages of the REV D thread... I'm a dumbass.

It is however great of you to explain why you did it and it is cool to know.

I'm going to print out the schematic today to accompany my other documentation.... that will teach me not ask stupid questions.

Mako, thanks again for a GREAT project, very fun and exciting... almost done with wiring and then just waiting on the Group Buy T-Pads and Ed's tranos, then hopefully some funky cool compression.

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: mnats on June 28, 2008, 08:24:25 AM
Quote from: "matta"
...after reading 40+ pages of the REV D thread...

I'm pretty sure there's no mention of the difference between the "D" and "F" ratio boards in this thread so you wouldn't have seen it anywhere but in that little snippet from my page (or the schematic). But  I seem to recall more than once referring people back to either my Rev D page or the schematic before in this thread.

I've pretty much resigned myself to the fact that try as I might I'll never make the page/videos/my posts obvious or clear enough for everyone to understand. Nor will it ever be completely obvious where to look to find the information you want, when you want it.

I'll keep trying though...and I appreciate the fact that you tried too before asking.

By the way if you do want to co-locate the GR disable with the attack knob like the original Mouser now has Alpha 25k pots with SPDT switches on them. I think the catalog says something about screwdriver adjust which might throw you off the track; I can confirm that they have a 1/4" shaft with about 8mm clear of the threads - the shaft is just slotted at the end. Mouser P/N 315-2415F-25K

Quote from: "matta"
Mako, thanks again for a GREAT project, very fun and exciting... almost done with wiring and then just waiting on the Group Buy T-Pads and Ed's tranos, then hopefully some funky cool compression.

I confess that I was never as excited about the sound of any of my earlier G1176-type builds - then I made the Rev D. I'm always reaching for this compressor now and have even started using it for the next calibration video's voice overs.

I owe a lot to Ed for encouragement and real, concrete help along the way as well others on this forum. Thanks, people.
Title: 1176LN Rev D DIY
Post by: 3nity on July 13, 2008, 09:29:51 PM
Hey guys i'm ordering parts for my 1176 D and i was wondering if its okay to use a simple pot in place of the T pad since everyone seems to use the T pad?

Thanks.
Title: 1176LN Rev D DIY
Post by: Criticalmass on July 15, 2008, 02:20:27 PM
Ok , this probably has to be THE most stupidest question....but I'll ask it anyhow......

Do you have to have the inputs and outputs or rather are the expensive transformer ins/outs there to make it sound better or are they needed to be able to use the thing :)

I've bought some Lundai (however you spell them) inputs, just having trouble getting the outputs.

I just wanted to be able to test that the main bits work before I bought the outputs.

Sorry for the terribly noobish questions, only ever built a phaser before so I'm new to all this. :oops:
Title: 1176LN Rev D DIY
Post by: Fredrik on July 16, 2008, 08:52:22 PM
I just missed the group buy of the T attenuator. Are there another one planned? And, does anyone know what the minimum order is from state?
Title: 1176LN Rev D DIY
Post by: Criticalmass on July 18, 2008, 04:47:37 AM
I take it my question above was too stupid to warrant an answer from someone :(
Title: 1176LN Rev D DIY
Post by: EmRR on July 18, 2008, 10:07:35 AM
Quote from: "Criticalmass"
I take it my question above was too stupid to warrant an answer from someone :(



read read read all 40 pages
Title: 1176LN Rev D DIY
Post by: okgb on July 18, 2008, 10:42:47 AM
Xfmr use depends on which version of 1176 pcbs you have ,
the D ver needs specific output xfmrs , the gyraf & previous mnats
has some options on the i/o , without looking at the thread can't be more
specific at the moment
Title: 1176LN Rev D DIY
Post by: spacecho on July 20, 2008, 06:47:36 AM
Hey Guys,

just wondering what voltage rating the 100uf electrolytics in this circuit are?

i read through the 42 page thread before asking here...

seems to be no mention in the schematic or bom on the mnats site.

I see that Mako's boards have 50v ones in there...

i'm just asking because i ordered 35v ones by accident...


thanks
Title: 1176LN Rev D DIY
Post by: EmRR on July 20, 2008, 08:01:31 AM
check the UREI manual.......
Title: 1176LN Rev D DIY
Post by: spacecho on July 20, 2008, 09:13:52 PM
thanks!

that was my next step - damm adobe viewer was crashing on my work computer...

will check it out at home
Title: 1176LN Rev D DIY
Post by: steve355 on July 21, 2008, 07:32:49 AM
NOOB electronics question time.... I have a couple of mnats boards + mini PSU and I've finished stuffing them, getting onto the wiring stage now. But I want to make a nice tidy job and I am trying to identify some suitable crimps, connectors etc that will help, to put in the pin holes in the PCB to be able to attach/detach wires as necessary|? Any ideas?

I bought a couple of 5mm PCB terminal blocks at the weekend, only to find the pins were too wide @ 0.9mm. Any  ideas?

Finally I need some spacers to go between the case and the PCB?.

Any ideas gratefully received... its driving me a bit nuts!! But I am getting close!


Thanks
Steve
Title: 1176LN Rev D DIY
Post by: pH on July 26, 2008, 10:00:42 PM
Quick question about using the input transformer board with the Altran: if I'm reading the board correctly I need to link B to C, and E to F, yes? This would link pins 2 and 3 to the ground plane of the little board.

Thing is, I completely missed this on my first Rev D and it still seems to work fine.

Can't find a pinout for the C-3837-1 so I'm wondering what's happening here.
 

Cheers,
Paul
Title: 1176LN Rev D DIY
Post by: mnats on July 27, 2008, 06:11:41 AM
Quote from: pH
Quick question about using the input transformer board with the Altran: if I'm reading the board correctly I need to link B to C, and E to F, yes?
(http://mnats.net/images/revd_trx_brd.gif)
Yes, that's what I put at the bottom of the board.
Quote from: pH
This would link pins 2 and 3 to the ground plane of the little board.
How do you figure? Note that where it says "Altran C-3837-1" there is an arrow indicating where pin 1 goes. That means pins 6 and 7 will be connected to the ground plane.

On the Altran, pin 6 goes to the can. On the Cinemag CMLI-15/15PCA (a 1:1 transformer not explicitly shown, but that shares the same footprint and pin 1 assignment) pin 6 goes to a shield and pin 7 goes to the can. It wasn't easy trying to fit all the information at the bottom of the board, so even though it says to connect the two links, only one is going to the can with the Altran.

Quote from: pH
Can't find a pinout for the C-3837-1 so I'm wondering what's happening here.
(http://mnats.net/images/C-3837-1.gif)
I've now linked to it from my Rev D page. Here it is courtesy of Ed.
Title: 1176LN Rev D DIY
Post by: matta on August 23, 2008, 04:38:45 AM
Well here is a cautionary tale...

I finally got all my pieces together for my REV D V2 1176, which I've been building over 3-4 months as time/money has allowed and I was ready for the final hook-up.

I printed the schematic so had it on record along with the original schematic for the UREI Rev D and thought I was prepared for things... but...

I noticed having soldered the screw terminals on the PCB it covered up the colour coding for the output transformer... no problem! I'll just print it out as it is laid out in MNATS beautiful document, so I do and wire up accordingly...

The big moment arrives, I flip the switch BRIGHT lights and flames as R32 goes up in smoke... hmm funny, I had checked my wiring all looked good, voltages were good, what went wrong?

So I desolder it and then work backwards... but wait R32 was going to the wrong winding.... something is fishy... I open up the MNATS REV 2 document and the output transformer colours DON'T match the board... penny drops!!!!

I had BOTH the REV1 and REV2 manuals of MNATS and while I was working from the correct schematic for REV2 and the UREI one (which is great since it shows that you have to join the CT Orange and Yellow wires together if you have Ed's transformer) but the OVERLAY was REV1 which DOESN'T match up with REV2 (Mako you may want to add this to your list of changes to your REV D site in case anyone else makes the same blundering mistake!).

So a quick resistor change and re wire of the output transformer and she is alive and well!!! She passes audio, clean as a whistle, all control work just got to get to the calibration steps.

My Meter in GR is deflecting all the way to the right, I assume I need to “0” it and hope that adjusting the “0” trim will sort that out. GR is moving downscale when audio passes and the Bypass and OUTPUT Meter selections are working, so all seems good here.

I just have a question about matching Q1 and Q11. Can one do this in circuit? I have installed DIL sockets so I can swap them out, but want to know if I can use say use just Q1's socket and surrounding circuit and just plug in various 2N5457's? Where would be the best place to measure and can anyone explain this procedure?

I know Mako has a 3rd Video installment he will hopefully be doing and not sure if this covers the matching process but it may be useful to know.

Thanks in advance and thanks to Mako for an AWESOME  project!!!

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: matta on August 23, 2008, 09:42:56 AM
And we are back... Hah hah

Ok,

So This morning a I set the "0" meter trimmer to zero and went through Mako's Calibration videos and set the 'Q Bias' and 'Null Adjust' trimmers as per his EXCELLENT videos!

So the last adjustment I need to make is to the "Tracking" trimmer.

As I shared I just put in 2 x 2N5457's in Q1 and Q11 as a starting point but they are not matched, but from what I gather they will have had no effect on the 2 set-up procedures I've done because in the 'Q Bias' set-up you short point 22 to Ground, effectively taking the GR circuit out of action.And in setting the 'Null Adjust' trimmer you take R44, the 'Tracking' trimmer out of circuit using a shorting plug.

Since there isn't a 3rd video yet I just want to know as per my above question, can one 'match' the 2 FET's in circuit? And then I'll have to refer to the UREI manual for the final set-up.

Thanks in advance!

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 02:04:57 PM
I am trying to find where "x" and "y" on the meter switch board wire to on the main board.
Title: 1176LN Rev D DIY
Post by: matta on August 23, 2008, 02:07:09 PM
Quote from: "bluezplaya"
I am trying to find where "x" and "y" on the meter switch board wire to on the main board.


They don't, they connect to the output XLR. "X" goes to Pin2, "Y" goes to Pin3.

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 02:09:33 PM
Thanks!
 :guinness:
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 04:06:14 PM
Matt, I am working on my unit right now and I noticed your thread about wiring the output transformer. I am using the Cinemag CM-96731. Where exactly is the color coding wrong? I certainly don't want to screw anything up when i turn it on.

Adam
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 04:11:09 PM
Matt, it looks as if R32 is in the signal path of the Violet and White/Red wire. Is that correct?
Title: 1176LN Rev D DIY
Post by: matta on August 23, 2008, 04:33:07 PM
Which REV board do you have?

Mako's overlays are correct, it just depends on which board you have.

The transformer colour code are as follows, both from the EDGE (near C14) of the PCB TOWARDS the AC input.

REV1: Brown | Violet | Whit/Black | Whit/Red | Black | Grey
REV 2: Brown | Whit/Black | Whit/Red | Black | Grey | Violet

You can tell the difference by noting the changes that happened between Board REV's which are on Mako's site, but for the record they are:

Rev D Version 2 changes:

* Fixed ground plane shorts on Q7 - Q10
* Added alternate pads for Q5, Q12, and Q13 so 2N5088s can be used in these positions too (like the Purple MC76) You can still use 2N5088 transistors for Q7 through Q10
* Made C2 and C11 0.2" pitch rather than 0.1"
* C18 Pitch narrower for better fit
* More room for Q6 + heat sink
* Ground pad near Pad 7 to aid proper wiring
* All pads for external wiring changed to 50 mil holes
* AC IN pads larger
* Place for shorting pins for R44 to assist calibration and room for three pin header to hold shorting plug - refer to PDF overlay
* Correct value of resistor R12
* Power supply has its own ground plane
* Final stage of line amp has its own ground path

The shorting pin near R44 will be the dead giveaway if you have a REV2 board or not.

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 04:40:41 PM
I have a Rev 2. It is confirmed then. I wired up correctly. While you're available online, I also would like to confirm the input transformer. I am using the Cinemag CMLI-15/15PCA and have it mounted to the board correctly. I have jumpered pins B and C, as well as E and F. I also jumpered the 2 links for "no H Pad". What is H Pad? Is that for wiring a 600 ohm attenuator? I will be using a 1k pot for now, until I can get my hands on an attenuator.

Also, J2 is not marked for any -/+ so I assume it shouldn't matter. I will wire J2 to the input connectors on the board. But where I'm slightly confused is where to wire the input pot...between pins 1 and 5? So that means 2, 3, and 4. But which is wiper, etc?

Thanks in advance,
Adam
Title: 1176LN Rev D DIY
Post by: matta on August 23, 2008, 04:53:30 PM
Quote from: "bluezplaya"
I have a Rev 2. It is confirmed then. I wired up correctly. While you're available online, I also would like to confirm the input transformer. I am using the Cinemag CMLI-15/15PCA and have it mounted to the board correctly. I have jumpered pins B and C, as well as E and F. I also jumpered the 2 links for "no H Pad". What is H Pad? Is that for wiring a 600 ohm attenuator? I will be using a 1k pot for now, until I can get my hands on an attenuator.

Also, J2 is not marked for any -/+ so I assume it shouldn't matter. I will wire J2 to the input connectors on the board. But where I'm slightly confused is where to wire the input pot...between pins 1 and 5? So that means 2, 3, and 4. But which is wiper, etc?

Thanks in advance,
Adam


Adam,

To the best of my knowledge the 'H Pad' is if you ARE using a pot since a 1K pot will not give you the desired taper than the circuit needs.... you will need to do some more research on this. You jumper the PAD IF you are using an attenuator.

Likewise you will need to see what others have done using a pot configuration, I believe it was spoken about earlier in this thread somewhere.

J2 is marked if you look at the PCB, note how one hole is Square, this indicate +, the round hole is -, it isn't on the overlay but look at the solder pads.

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 05:03:59 PM
Well... :?  I guess I will have to desolder the screw terminal just to look under there  :grin:
Title: 1176LN Rev D DIY
Post by: bluezplaya on August 23, 2008, 05:37:11 PM
Okay, I found the positive hole on the main board but don't know where the positive side is on the IP tranny board.
Title: 1176LN Rev D DIY
Post by: matta on August 24, 2008, 03:18:41 PM
Quote from: "bluezplaya"
Okay, I found the positive hole on the main board but don't know where the positive side is on the IP tranny board.


Glad you found that  :thumb:

On the main PCB is should be on the right side off the edge of the PCB. I think it is only natural that the PIN 2 and PIN 4 on the input side would like up on the output on the input transformer PCB, so the hole closest to Pin 2 if you look at the PCB horizontally is + and Pin 4 is -. I hope that helps.

Also going to use this as a BUMP for my own questions RE FET matching for the GR section, any help would be appreciated.

Any other REV D builders around?

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on September 08, 2008, 06:34:29 PM
(http://www.adamholtmusic.com/daven.jpg)

I just picked up this Daven 600 ohm stepped and was wondering how I should wire it up.
Title: 1176LN Rev D DIY
Post by: pH on September 08, 2008, 10:51:19 PM
Sounds familiar...

http://www.groupdiy.com/index.php?topic=26373&highlight=daven
Title: Will this meter work?
Post by: Mrosso on September 09, 2008, 06:11:02 PM
Will the Nessai Meter listed on JLM audio's website work for the 1176 Rev D? It says its a Sifam AL29WF look-alike. I've been trying to find an affordable Sifam, but no luck so far. I'm assuming the buffer circuit must be included, no?

http://www.jlmaudio.com/VU%20Buffer.htm
Title: 1176LN Rev D DIY
Post by: kazper on September 10, 2008, 03:12:40 AM
I paid $80 for a sifam and LED light new, bulb was way cheaper. I don't think you will get better for much less than that.
Title: 1176LN Rev D DIY
Post by: crisotop on September 10, 2008, 03:38:25 AM
Quote
Also going to use this as a BUMP for my own questions RE FET matching for the GR section, any help would be appreciated.


Hey Matt, I used the little testrig as found in PRR's Post (http://www.groupdiy.com/index.php?topic=4531&highlight=fet+matching) (in the middle of the page, 05. Jan 2005, 6:17). It's not an 'in-circuit' method, but worked perfectly on my two revision J stereo clones.

hth,
christoph
Title: 1176LN Rev D DIY
Post by: matta on September 10, 2008, 10:46:26 AM
Hi Christoph,

Thanks very much, it was most useful and I not have a matched pair of FET's, wrote down all the measurements of the others incase I need to find similar/same one later (though out of 20 I got one pair).

Cheers

Matt

Quote from: "crisotop"
Quote
Also going to use this as a BUMP for my own questions RE FET matching for the GR section, any help would be appreciated.


Hey Matt, I used the little testrig as found in PRR's Post (http://www.groupdiy.com/index.php?topic=4531&highlight=fet+matching) (in the middle of the page, 05. Jan 2005, 6:17). It's not an 'in-circuit' method, but worked perfectly on my two revision J stereo clones.

hth,
christoph
Title: 1176LN Rev D DIY
Post by: matta on September 10, 2008, 10:47:03 AM
Hi Christoph,

Thanks very much, it was most useful and I not have a matched pair of FET's, wrote down all the measurements of the others incase I need to find similar/same one later (though out of 20 I got one pair).

Cheers

Matt

Quote from: "crisotop"
Quote
Also going to use this as a BUMP for my own questions RE FET matching for the GR section, any help would be appreciated.


Hey Matt, I used the little testrig as found in PRR's Post (http://www.groupdiy.com/index.php?topic=4531&highlight=fet+matching) (in the middle of the page, 05. Jan 2005, 6:17). It's not an 'in-circuit' method, but worked perfectly on my two revision J stereo clones.

hth,
christoph
Title: Mnant rev D R32 blowing
Post by: kdawg on September 18, 2008, 03:58:04 PM
Hello - I have built Mnant's rev D 1176 (version 1) with a UTC o-12 input and CM-96731 output transformer. It is working, but then after a few hours R32 (39 ohm) decides to commit suicide. Its only a 1/4 watt, does it just need to be beefier or is there a bigger issue?

I wired the output transformer according to Version 1 board colors (not Version 2 like I saw someone did on another post) and its compressing and the output is good as well. Remaining leads from tranny not attached to board go to the XLR and meter input.

ALSO - I do have a bit of humm going on when I crank it enough... could this be because R32 is open? I tried moving input tranny around, no change. I do have the Cinemag screwed directly to chassis - any isolation required? Power toroid mounted on opposite side of chassis.

-kdawg
Title: Re: Mnant rev D R32 blowing
Post by: Andre on September 18, 2008, 06:30:05 PM
Quote from: "kdawg"
Hello - I have built Mnant's rev D 1176 (version 1) with a UTC o-12 input and CM-96731 output transformer. It is working, but then after a few hours R32 (39 ohm) decides to commit suicide. Its only a 1/4 watt, does it just need to be beefier or is there a bigger issue?

I wired the output transformer according to Version 1 board colors (not Version 2 like I saw someone did on another post) and its compressing and the output is good as well. Remaining leads from tranny not attached to board go to the XLR and meter input.

ALSO - I do have a bit of humm going on when I crank it enough... could this be because R32 is open? I tried moving input tranny around, no change. I do have the Cinemag screwed directly to chassis - any isolation required? Power toroid mounted on opposite side of chassis.

-kdawg



I won't worry about the hum until you solve the resistor problem.  What voltages do you read over the resistor and in the area?
Title: 1176LN Rev D DIY
Post by: crisotop on September 19, 2008, 03:45:34 AM
Quote
Thanks very much, it was most useful and I not have a matched pair of FET's, wrote down all the measurements of the others incase I need to find similar/same one later (though out of 20 I got one pair).


brilliant - do you want  to build a stereo-linkable version? because I still have got a matched pair flying around somewhere (I was really lucky, out of 10 I got 2 matched pairs for a dual and one single pair!)...

regards,
christoph
Title: Re: Mnant rev D R32 blowing
Post by: kdawg on September 21, 2008, 01:25:50 PM
I took some measurements but of I course I left them at my shop. I do remember I have 10.5 volts across R32 when it is blown. 30.5 volts on the main rail, -10 volts on the negative rail.

Seems that would be about .26 mA across R32, and about 2.8 watts... hmmm?
a bit more than a 1/4 w!

I'll get the other measurements soon, thanks.

-kdawg
Title: 1176LN Rev D DIY
Post by: mitsos on September 21, 2008, 04:12:44 PM
Quote from: "kazper"
I paid $80 for a sifam and LED light new, bulb was way cheaper. I don't think you will get better for much less than that.

please don't tease us... :grin: where?
Title: 1176LN Rev D DIY
Post by: Chrome Heart on September 21, 2008, 06:19:10 PM
Where are you guys buying pcb's for this project? I saw Hairball audio had some. Is there a preferred supplier?
Title: 1176LN Rev D DIY
Post by: Hairball Audio on September 21, 2008, 08:59:00 PM
Mnats sells the boards for the revision D version.  Info is located here:
http://www.groupdiy.com/index.php?topic=330976

I just sell PCB's for the pushbutton switches.

Mike
Title: 1176LN Rev D DIY
Post by: Chrome Heart on September 21, 2008, 10:14:11 PM
Thanks Mike.
Title: 1176LN Rev D DIY
Post by: kazper on September 22, 2008, 12:13:36 AM
Quote from: "mitsos"
Quote from: "kazper"
I paid $80 for a sifam and LED light new, bulb was way cheaper. I don't think you will get better for much less than that.

please don't tease us... :grin: where?


http://www.meterdistributor.com/
Title: 1176LN Rev D DIY
Post by: Miska on September 22, 2008, 04:45:36 AM
Does anyone know if Alpha rotary switches can be programmed like Lorlins can? I can't find the info in the datasheet...

I have located a 6 position Alpha switch and I would like to use it for ratio/slam and wire it like Mnats did. It has 1 position too much though...

Or even better:
A source for 2 deck 2 pole 5 pos rotary switch in Europe? All I could find was this:
http://www.banzaieffects.com/Rotary-Switch-2-level-2x2x6-pr-20275.html

/Miska
Title: 1176LN Rev D DIY
Post by: crisotop on September 22, 2008, 05:43:59 AM
www.conrad.de (http://www1.at.conrad.com/scripts/wgate/zcop_at/~flNlc3Npb249UDkwX0NPUF9BVDpDX0FHQVRFMDE6MDAwMC4wMGQ2LjAxODdkNWVkJn5odHRwX2NvbnRlbnRfY2hhcnNldD1pc28tODg1OS0xJn5TdGF0ZT0yMzAzNzI5MDYw====?~template=PCAT_AREA_S_BROWSE&mfhelp=&p_selected_area=%24ROOT&p_selected_area_fh=&perform_special_action=&glb_user_js=Y&shop=AT2&vgl_artikel_in_index=&product_show_id=&p_page_to_display=DirektSearch&~cookies=1&zhmmh_lfo=&zhmmh_area_kz=&s_haupt_kategorie=&p_searchstring=709387%A0-%A062+&p_searchstring_artnr=&p_searchstring_manufac_artnr=&p_search_category=alle&r3_matn=&insert_kz=&gvlon=&area_s_url=&brand=&amount=&new_item_quantity=&area_url=&direkt_aufriss_area=&p_countdown=&p_80=&p_80_category=&p_80_article=&p_next_template_after_login=&mindestbestellwert=&login=&password=&bpemail=&bpid=&url=&show_wk=&use_search=3&p_back_template=&template=&kat_save=&updatestr=&vgl_artikel_in_vgl=&titel=&darsteller=&regisseur=&anbieter=&genre=&fsk=&jahr=&jahr2=&dvd_error=X&dvd_empty_error=X&dvd_year_error=&call_dvd=&kna_news=&p_status_scenario=&documentselector=&aktiv=&gewinnspiel=&p_load_area=$ROOT&p_artikelbilder_mode=&p_sortopt=&page=&p_catalog_max_results=20) #709387 - 62

hth, christoph
Title: 1176LN Rev D DIY
Post by: Miska on September 22, 2008, 06:01:11 AM
That's grand!!!!

Many thanks, Christop! The switch doesn't exist on the swedish Conrad site. That's why I couldn't find it...

/Miska
Title: r32 smoking
Post by: kdawg on September 24, 2008, 07:32:55 PM
I'm reposting the message above with voltages just so it's all together:
------
Hello - I have built Mnant's rev D 1176 (version 1) with a UTC o-12 input and CM-96731 output transformer. It is working, but then after a few hours R32 (39 ohm) decides to commit suicide. Its only a 1/4 watt, does it just need to be beefier or is there a bigger issue?

I wired the output transformer according to Version 1 board colors (not Version 2 like I saw someone did on another post) and its compressing and the output is good as well. Metering is OK too.

VOLTAGES (when r32 is gone)
30.5 volts on power rail
R26 / R34 Junction - 20.3 V
Brown TX wire - 19.5 V
Black TX Wire - 30.5 V
White/Black TX wire - 11 V
White/Red TX wire - 10V
Across R32 spot - 10 V

Is there any reason why the PCB would need isolated ground from chassis? Input transformer needs to be isolated?

-kdawg
Title: 1176LN Rev D DIY
Post by: bluezplaya on September 29, 2008, 08:11:41 PM
Can anyone post a diagram of how to wire the attenuator. I decided to buy one from Hairball Audio and I don't quite know how to wire it.
Title: 1176LN Rev D DIY
Post by: Hairball Audio on September 29, 2008, 10:19:53 PM
Have you seen the post by Matta about 1/2 down this page?

http://www.groupdiy.com/index.php?topic=27741&postdays=0&postorder=asc&start=180

Mike
Title: 1176LN Rev D DIY
Post by: bluezplaya on September 29, 2008, 10:42:34 PM
:wink:
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 03, 2008, 04:38:06 PM
Okay, so I finally got my IEC plug in the mail from Mouser and wired it up to the power transformer. My AC voltages look good from the power transformer and the 30v is good from R87 and -10v from CR6. I powered up and immediately started hearing some high pitch ringing or singing or something from the output transformer. I patched in some audio and listened through headphones to hear a signal and all I got was some seriously scratchy and poppy and distorted sounds ( and no, I wasn't listening to Nine Inch Nails).

The input seemed to be working like it should, the output knob was the culprit. It spit, popped, cussed at me in every way as I turned it. The meter was jumping somewhat; when I was able to dial in somewhat of a grainy signal, the ratio, attack and release appeared to be working, given the signal it hard to work with.

I'm using the Rev2 board, Cinemags, lorlin switches and the attenuator from Hairball Audio and wired just like the pic from Matta. I'm using shielded cable for the input stage and solid wiring for the ratio board, etc.

Do I need to look at transistors? Is this something wrong with the output stage? The Cinemag is wired correctly from the output.

Any help appreciated.
Adam
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 22, 2008, 04:18:30 PM
I'm stranded on a DIY island for 19 days and no one has replied to my cry for help!  :green:

I spent some more time today with the Rev. D to try and figure this thing out. I double checked both input and output transformers, seems good. I swapped transistors in the line amp stage and got the same results (they were fine.) Do I need to look at replacing Q1 or Q6 transistors?

When feeding a strong signal through it I still get a high pitch squeal that my dog isn't too crazy about. There's also distortion on the signal. I can hear a difference in the signal when I switch the bypass on and off and I'm pretty sure the ratio and attack and release switch and knobs seem to be changing the sound.

I notice in bypass mode the meter doesn't move (obviously), in GR mode there is no movement, and in VU mode it jumps right along with the signal. Is there something wrong with my meter, or does this not have any affect on the problem?

HEEEEELPPP! I'M STRANDED!!!!!
Title: tracking?
Post by: nielsk on October 24, 2008, 09:50:58 AM
My first units is up and running, sounds good, compressing fine, but there is no meter tracking adjustment. Meter works correctly for input and output, I can confirm 10 dB of compression with the compresor "in" and no compression with it out, but in GR meter mode there is no change over the full swing of the tracking adjusment trimpot. Everything else adjusts correctly. I see around 1-1/2 dB of deflection on the meter in GR mode, and if I crank up the input it goes down, but there is no way to get it match the actual amount of compression. I confirmed the trimpot, the jumper, the meter.... ANY ideas?
BTW I am using 2n5088s for Q12 & 13
Title: 1176LN Rev D DIY
Post by: matta on October 24, 2008, 12:07:14 PM
No offense bluezplaya, but your question above reads like me going to a mechanic and saying my car is broken... and then not giving and explanation of why or allowing the mechanic to see it!

HELP US, HELP YOU! How a about a pic to check your placement is correct, how is your grounding? You have given us VERY little to work with...

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 12:11:27 PM
Quote from: "matta"
No offense bluezplaya, but your question above reads like me going to a mechanic and saying my car is broken... and then not giving and explanation of why or allowing the mechanic to see it!

HELP US, HELP YOU! How a about a pic to check your placement is correct, how is your grounding? You have given us VERY little to work with...

Cheers

Matt


None taken! A pic on the way :roll:
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 01:08:39 PM
(http://www.adamholtmusic.com/bf5.jpg)
(http://www.adamholtmusic.com/bf2.jpg)
(http://www.adamholtmusic.com/bf1.jpg)
(http://www.adamholtmusic.com/bf3.jpg)
(http://www.adamholtmusic.com/bf4.jpg)
(http://www.adamholtmusic.com/bf6.jpg)

I hope these help. Let me know of any specific shots needed. I double checked the wiring for the ratio, attack, and release functions and they seems good.

Thanks for the help.
Title: 1176LN Rev D DIY
Post by: matta on October 24, 2008, 02:23:16 PM
Um... all your onboard trimmers are incorrectly soldered in.... see pics help  :?

You may also want to put some heat shrink over your exposed shield wires and did you deliberately omit the shorting plug in the GR Meter Driver part of the circuit?

Also you may be a bit late now but if I were you I would have put in some sockets for your 2N5457's... seems you soldered em in, brave  :cool:

Now go fix your mistakes with the trimmers :thumb:

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 02:36:25 PM
Ooh...I see the trimpots. I thought they were soldered correctly. On the board there are 3 solder holes together and then one seperately. So I need to move the leg under the trim screw to the "lone" hole and the middle and other leg of trimmer to the middle and other hole (closest to single hole)? I presume that is the way.

The shorting plug in the GR Meter driver?! Below the tracking adjust trimmer? Where do i wire it to?

Thanks a MILLION  :green:
Title: 1176LN Rev D DIY
Post by: matta on October 24, 2008, 02:47:10 PM
Adam,

Man, this is NOT paint by numbers... try put in a LITTLE effort.... just THINK about it... the way you have your trim pots now the legs are ALL shorting with each other, surely you don't want them that way?

What seems LOGICAL? Just look at the schematic, and if you don't understand THEN ask questions...

You don't even have to look that hard as MANY folks in this thread have posted pics, many of which use the multiturn trimmers... how about just LOOKING at MNAT's pics in this thread?

Take a look at the FIRST post in this thread and take a moment to visit MNAT'S REV D page and LOOK at his board and watch the videos... I mean he has gone to ALOT of effort to provide all this info and so many don't even bother to look at it or watch his GREAT videos (Mako, you totally rock and thank you for all the work you DO put in, I really appreciate it!).

If I can spend several hours reading these posts (and I have, more than once), surely the same could be expected of you?

Cheers

Matt

Quote from: "bluezplaya"
Ooh...I see the trimpots. I thought they were soldered correctly. On the board there are 3 solder holes together and then one seperately. So I need to move the leg under the trim screw to the "lone" hole and the middle and other leg of trimmer to the middle and other hole (closest to single hole)? I presume that is the way.

The shorting plug in the GR Meter driver?! Below the tracking adjust trimmer? Where do i wire it to?

Thanks a MILLION  :green:
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 03:04:22 PM
Quote
Man, this is NOT paint by numbers... try put in a LITTLE effort....


EFFORT?

4x Neve 1290
8x Green Pre
2x API 312
12x JLM Baby Animal
1x SSL Comp
2x Pico dual mono
1x Pico Stereo
2x Pultec
Complete recap and EQ mod on 16 channel Yammy, plus PSU
...now 4x S800

I'm TOTALLY not lashing out toward that remark but I'm thinking...holy crap, that was a bit out of nowhere. The trimpots were a total oversight and I think I DO put a bit of effort in ALL my builds.

Anyways, like I said, I totally appreicate the help but I guess I'll try and take it from here.

Peace,
Adam
Title: 1176LN Rev D DIY
Post by: matta on October 24, 2008, 03:40:33 PM
Yes, EFFORT!

Nobody is debating you have a high turn over of DIY gear or effort into their build, but in this case ALL the info to your questions lay in this SINGLE thread.... you can't tell me you managed to miss them all?

I say zeal without knowledge is a dangerous combination.... I'm talking about EFFORT into looking at the schematics, or even READING this thread.

My mood swing was not sparked out of nowhere... you claimed to be on some desert island and nobody is hearing your cry for help... I'm not aware you ever sent SMOKE signals to start with... how about being more proactive!

In those 19 days you mentioned you didn't once bother to post a pic or word your questions that would help us be of any help to you.... it took me all of 2 minutes to find your problems and point out another one, and the same in the S800 thread.

I've been working 18 hour days this week in studio and in what little free time I have I am trying to get on here and be of help, and feel I've done that for you... in fact I know I have... all I'm asking is that you try and be more proactive and help us help you and try and learn from your mistakes.

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 03:55:15 PM
Well... "hey dumbass, try turning the trimpots the other way around" would have been better than "give a little effort around here." Anyhow, the board's layout was misleading "to me in my ignorance" in regards to the trimpot. I had a total brain fart when I saw the turn screw imprint and decided to mount the trimpots that way.

So anyhow, the compressor is working now. Back to mixing.
Title: Re: tracking?
Post by: mnats on October 24, 2008, 03:59:51 PM
Quote from: "nielsk"
I see around 1-1/2 dB of deflection on the meter in GR mode, and if I crank up the input it goes down, but there is no way to get it match the actual amount of compression.

Assuming you have done the null adjust trim, have you matched the Meter Driver FET with the gain reduction FET? Sometimes you'll luck out and be able to get your meter adjusted reasonably well with a random pair but sometimes not.
Quote from: "bluezplaya"
EFFORT?

I don't think Matta was referring to the volume of stuff you've built but rather your question about the pads on the gain reduction meter circuit. They are referenced in the text of my Rev D page, the V2 PDF linked from that page and the calibration video. So he might have meant "effort" in the sense of have you looked at that page?

Oh, I see you've had another exchange since I've been slowly typing. So your gain reduction meter circuit is also working OK?
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 04:04:07 PM
Have not trimmed the meter yet. But I know about the videos. Now that it is working, that is my next step before sliding it in the rack of toys.

Thanks Mnats,
Adam
Title: Re: tracking?
Post by: matta on October 24, 2008, 04:08:13 PM
Quote from: "mnats"
Assuming you have done the null adjust trim, have you matched the Meter Driver FET with the gain reduction FET? Sometimes you'll luck out and be able to get your meter adjusted reasonably well with a random pair but sometimes not.


Amen to that... I put in some random FET's in mine and my meter was all over the place... needed to match em and all seems well. Mako has some GREAT videos on his REV D page on the set-up of the NULL Adjust and Q Bias, great viewing and I'm trying to encourage him to get the 3rd one down... they are greatly informative!

Quote from: "bluezplaya"
EFFORT?


Quote from: "mnats"
I don't think Matta was referring to the volume of stuff you've built but rather your question about the pads on the gain reduction meter circuit. They are referenced in the text of my Rev D page, the V2 PDF linked from that page and the calibration video. So he might have meant "effort" in the sense of have you looked at that page?

Oh, I see you've had another exchange since I've been slowly typing. So your gain reduction meter circuit is also working OK?


Exactly, and before I go anywhere else, Mako, thanks again man, you bust your balls to give us these great projects and from the bottom of my heart, thank you! Your new REV A looks great... tell me... do you EVER take a break from this :shock:

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 04:17:49 PM
Yeah, this project would have worked from the first time I fired it up had it not been for those trimpots being in the wrong way. So the calibration videos are on the mnats website? And on this thread?
Title: 1176LN Rev D DIY
Post by: bluezplaya on October 24, 2008, 04:18:46 PM
Nevermind. I fount them.
Title: gr meter
Post by: nielsk on October 24, 2008, 05:05:31 PM
Thanks for the reply
I have done the bias, null and "0" adjustments, they all work fine. As I said, it is compressing correctly. I have built 8 of the MC67s, they all worked fine and adjusted out correctly (and had a condiderable range of adjustment on the tracking), without matching the FETs. It seems unlikely that the FETs would be so out of spec that there would be no adjustment range at all..... I will try replacing the FET in the meter circuit, maybe it is bad. I have checked all the resistors, the trim pot, and the jumper, NPF.....
I keep thinking I did something stupid but I can't see it.
What should I see at the output of the GR FET?
Has anyone else built a REV2 with the 5088s?
Title: Re: gr meter
Post by: matta on October 24, 2008, 06:27:38 PM
Quote from: "nielsk"
Thanks for the reply
I have done the bias, null and "0" adjustments, they all work fine. As I said, it is compressing correctly. I have built 8 of the MC67s, they all worked fine and adjusted out correctly (and had a condiderable range of adjustment on the tracking), without matching the FETs. It seems unlikely that the FETs would be so out of spec that there would be no adjustment range at all..... I will try replacing the FET in the meter circuit, maybe it is bad. I have checked all the resistors, the trim pot, and the jumper, NPF.....
I keep thinking I did something stupid but I can't see it.
What should I see at the output of the GR FET?
Has anyone else built a REV2 with the 5088s?


Hey Nielsk,

Can you confirm that your GR METER has a path to Ground? Something overlooked with those used to the G/H Gyraf units (myself included!).

This from Mako's site

Quote
One subtle difference is that the GR (Gain Reduction) meter setting doesn't ground one terminal of the VU meter in the discrete version as it does in the IC circuit and special rotary control PCBs have been designed with this in mind.


Sorry if it seems rudimentary, just taking a shot in the dark here with you :thumb:

Cheers

Matt
Title: 1176LN Rev D DIY
Post by: nielsk on October 24, 2008, 06:45:40 PM
I have points 28 & 29 going to the meter in the GR switch setting, as per the schematic. 28 is to +30 via R79 (15K) and 29 is from the collector of Q13
I did not use the switch board, this is wired directly to the switch.
Title: Re: gr meter
Post by: mnats on October 24, 2008, 08:56:18 PM
Quote from: "nielsk"
Thanks for the reply
I have done the bias, null and "0" adjustments, they all work fine. As I said, it is compressing correctly. I have built 8 of the MC67s, they all worked fine and adjusted out correctly (and had a condiderable range of adjustment on the tracking), without matching the FETs.

I was not implying that the unit doesn't compress or that you don't know how to build things and I agree that I seldom have had to match FETs within a unit. I'm not good at distance troubleshooting probably because...
Quote from: "nielsk"
It seems unlikely that the FETs would be so out of spec that there would be no adjustment range at all.....

...I completely missed this from your earlier post. I thought you could adjust but it was just out of range. I had this problem myself on the Rev A I just built. I could not get it to show a -10dB drop as it was just a little bit beyond the range of the trim pot. That's why I mentioned it. Sounds like the trimmer is out of circuit, but you said you checked the jumper...
Quote from: "nielsk"
What should I see at the output of the GR FET?

A change in the DC voltage at the source of Q11 of about 100mV when the unit is compressing 10dB.
Quote from: "nielsk"
Has anyone else built a REV2 with the 5088s?

Yes, I built my last one with '5088s in the Gain Reduction Control Amp. But there's no reason to believe they wouldn't work in the Meter Driver - the circuit isn't asking the transistors to do anything extraordinary...
Title: 1176LN Rev D DIY
Post by: mnats on October 25, 2008, 11:56:15 PM
I received another email. As stated in the Rev D board sales 1st post:
Quote from: mnats
Please do not PM or email questions to me about boards, ordering or this project. Questions that are PMed or emailed to me will be paraphrased and answered in this or the project thread.
Quote from: Someone living in the UK
Is there a wiring guide/parts list etc for your dual 1176 layout?
As stated on my Rev D page:
Quote from: mnats
Generally, wiring the Revision D is the same as wiring a rotary version of the G1176 (http://mnats.net/1176-wiring-rotary.html).
Of course you can just use the one included power supply. As for the parts list, that is also linked from my Rev D page. Surely you do not need me to multiply the number of parts times 2 for two units?
Title: no gr meter adj
Post by: nielsk on October 26, 2008, 01:13:49 PM
I managed to get some measurements off a correctly working MC76, terminal D of Q11 goes from +4.6v (compression off) to + 2.9V (compression on, 10dB). On the Rev2 I am seeing +10.2 to +9.8. I removed R76 & R67, they are correct.
Terminal S goes between -1.2v to -1 v
Terminal G from -1.2 to -0.98
Title: 1176LN Rev D DIY
Post by: nielsk on October 27, 2008, 08:53:54 AM
Doooohhhh! finally found the bad solder joint..
all is good, the board works great ( I must add that I am not fond of the black boards, I find being able to shine light through the boards a very useful troubleshooting technique)
the moral of the story is,: check, check and re check. if it is not working, it is your own fault :oops:
Title: 1176LN Rev D DIY
Post by: jdbakker on October 27, 2008, 10:41:10 AM
Quote from: "nielsk"
( I must add that I am not fond of the black boards, I find being able to shine light through the boards a very useful troubleshooting technique)

That's probably more to do with the rather opaque solid copper ground plane on one side of the board than with the color of the solder mask, BTW.

JDB.
Title: 1176LN Rev D DIY
Post by: nielsk on October 27, 2008, 10:58:27 AM
ahhh, so kimosabe'
that does make sense, and I'm sure the build is easier and the board smaller because of the use of the ground plane on the top side. It is still much easier to see traces (and faults) on the translucent green boardstock
Title: 1176LN Rev D DIY
Post by: jdbakker on October 27, 2008, 11:07:57 AM
Quote from: "nielsk"
It is still much easier to see traces (and faults) on the translucent green boardstock

Absolutely. Debugging a design (or even debugging your assumptions about a design) can be made easier by the Insta-XRay view that you get by holding the board up to the light. Just wanted to point out that in this particular case...

JDB.
Title: 1176LN Rev D DIY
Post by: khstudio on November 01, 2008, 02:21:50 PM
Sorry if it has been asked but finding a 2200uf 35v for (C24) is driving me nuts.  :sad:

That's a BIG cap for a small spot on the PCB.

Will a 1000uf be sufficient for (C24):?:
Title: 1176LN Rev D DIY
Post by: dissonantstring on November 01, 2008, 04:39:46 PM
hi kevin,
i can't remember what I used, but if space is tight I usually go for Panasonic NHG lytics.  usually, they are smaller (height and most times OD).
what's the pin spacing and OD of the footprint on the Rev.D board?
-grant
Title: 1176LN Rev D DIY
Post by: khstudio on November 01, 2008, 04:51:40 PM
Quote from: "dissonantstring"
hi kevin,
i can't remember what I used, but if space is tight I usually go for Panasonic NHG lytics.  usually, they are smaller (height and most times OD).
what's the pin spacing and OD of the footprint on the Rev.D board?
-grant


OD = 13mm
LS = 5mm

VERY small for a 2200u @ 35v  :?
Title: 1176LN Rev D DIY
Post by: khstudio on November 01, 2008, 04:58:43 PM
Quote from: "mnats"
Quote from: "pH"
Quick question about using the input transformer board with the Altran: if I'm reading the board correctly I need to link B to C, and E to F, yes?

(http://www.geocities.com/m_natsume/images/revd_trx_brd.gif)
Yes, that's what I put at the bottom of the board.

That means pins 6 and 7 will be connected to the ground plane.

On the Altran, pin 6 goes to the can. On the Cinemag CMLI-15/15PCA (a 1:1 transformer not explicitly shown, but that shares the same footprint and pin 1 assignment) pin 6 goes to a shield and pin 7 goes to the can. It wasn't easy trying to fit all the information at the bottom of the board, so even though it says to connect the two links, only one is going to the can with the Altran.

Quote from: "pH"
Can't find a pinout for the C-3837-1 so I'm wondering what's happening here.

(http://www.geocities.com/m_natsume/images/C-3837-1.gif)
I've now linked to it from my Rev D page. Here it is courtesy of Ed.


I'm assuming that Pin 7 on the ALTRAN is a dead/open Tap & doesn't connect to anything inside :?:
Title: 1176LN Rev D DIY
Post by: mnats on November 01, 2008, 05:14:35 PM
Quote from: "khstudio"

OD = 13mm
LS = 5mm

VERY small for a 2200u @ 35v  :?

For what it's worth I used a Nichicon UVZ1V222MHD . The screen printed outline isn't there to dictate how big a cap you can use; there is enough room for a 16mm diameter cap where C24 goes...
Quote from: "khstudio"
I'm assuming that Pin 7 on the ALTRAN is a dead/open Tap & doesn't connect to anything inside

Got a multimeter?  :wink:
Title: 1176LN Rev D DIY
Post by: dissonantstring on November 01, 2008, 05:19:04 PM
hi kevin,
looking at the overlay i think i remember now that i bent the legs for both C26 and C24 at right angles having the bodies of the cap move out towards the edge of the board to allow room for both caps.  not the most steady for the caps, but you can zip-tie the two caps together once they are soldered in for a little more stability.  looking at my build pics i think i used PWs! :shock:  :grin:
regards,
grant
Title: 1176LN Rev D DIY
Post by: khstudio on November 01, 2008, 05:26:55 PM
Thanks Guys!  :thumb:

Quote
Got a multimeter?


You got me... I knew that. :cool:
Title: 1176LN Rev D DIY
Post by: luis on November 08, 2008, 09:34:52 PM
Can the R44 Trimer be 2k instead of 1k (mnats boom is 1k)?

I ordered 2k :(

Thank you,
Luis
Title: 1176LN Rev D DIY
Post by: dissonantstring on November 08, 2008, 09:51:37 PM
hi luis,
you can use the 2K trim pot, it won't hurt anything.  it's a multi-turn trim pot so you should still be able to dial in whatever resistance you'll need fairly easily.
regards,
grant
Title: 1176LN Rev D DIY
Post by: luis on November 08, 2008, 09:54:04 PM
Thank you,

Soldering right now !
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 16, 2008, 05:43:03 PM
OMFG, still having problems wiring the T Attenuator? Labbie Neeno  drew a nice picture (http://www.groupdiy.com/index.php?topic=308767#308767) for you.

This link appears to be dead.  Does anyone have the actual link or diagram?  I'm using a Mallory 600 ohm T-Pad and I'm a bit confused exactly how to wire it up to the board.  Yes, yes, I have read over the thread for many hours today but many links appear to be dead, and the search function seems to not be as usable as before.

Thanks!
Sig

Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 16, 2008, 07:59:22 PM
Thanks!

This may help others visualize it.

(http://www.matt-allison.com/diy/1176/1176_attenuator.jpg)

Sorry about the bad quality of the pic... cell phone camera was all I had handy.

Cheers

Matt

The Mallory T-Pad appears to have the identical layout to this pic - can anyone please confirm if I can wire it in the same fashion?

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: edanderson on November 16, 2008, 11:48:16 PM
yes.

ed
Title: Re: 1176LN Rev D DIY
Post by: mnats on November 17, 2008, 06:01:16 AM
This link appears to be dead...and the search function seems to not be as usable as before.
Link is fixed now, but it refers to a bridged T pad that some people have been using.

I was able to find neeno's post in five seconds flat with the new forum's search function, so thanks to Ethan for our upgrade.

Didn't your Mallory come with a diagram? Mine did.
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 17, 2008, 09:53:59 AM
Yep, I found the new link too while going through the entire thread - spent 6 hours yesterday reading every tidbit.  My Mallory's did not come with a sheet.  When I saw this new T-Pad, it looked very similar so I just assumed it would have the same connections.

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: nielsk on November 17, 2008, 03:32:52 PM
Is there a schematic for the extra power supply board that came with my rev D boards?

Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 17, 2008, 04:50:13 PM
The extra PS board should be the same for all revisions.

http://www.geocities.com/m_natsume/psu.html

Schematic download link in the upper left.

Mike
Title: Re: 1176LN Rev D DIY
Post by: nielsk on November 17, 2008, 04:56:08 PM
Aha!
thanks
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 03:14:26 PM
Can I ask where you guys are connecting the 12v Sifam lamp to?  The G1176's had connections on the board, but I don't see one on the Rev D's.  I've read of a few different ways, like tapping off the toroid AC, but I'm not totally sure what is the best/cleanest/quietest way.

Thanks so much!
Sig

EDIT - Ok, so I've used the Toroid like most others have, and simply put a 180ohm resistor on the positive leg, and I get 12.1vAC, and it appears to work well and looks nice and bright.

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 04:08:38 PM
Ummm...ignore that.  That was really bad what I did.  The light got REALLY hot after a minute, and then my meter jumped and peaked.  Can anyone please tell me the proper way to hook up the Sifam 12v lamp on these?

Thank you,
Sig

Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 18, 2008, 04:14:51 PM
I remember Jakob saying using the transformer secondaries was the cleanest way of doing it.

For my unit I used the VU pads on the rev J board.  If I recall that voltage was about 30v (close to the transformer secondary, except DC I think).  I used two 2W resistors on each VU pin leads...I think they were like 180 and 150ohm.  You want to get closer to 11v so the lamp will last longer.  This is all from memory as I am at work right now.

You didn't use a 1/4 watt resistors did you?  They would get fried.

EDIT:  Oh I just see now that you said the REV D.  Doesn't have VU connections.  Sorry...probably best to ignore me ;)

Mike
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 04:25:25 PM
Well, I did use the transformer secondaries (right at the point where the signal enters the black Rev D board) but, I do believe this would be an AC signal, not DC, correct?

I was using 1/4 watt resistors, don't have any 2 watt that would work at all right now.  It's not that the resistor fried, but the lamp itself was getting hot so I disconnected it fast before it could cause any damage.  I don't understand though, if I'm reading 12.1v, it should be fine, no?  Or is the current too high?  Or should I not be using an AC signal?  Very confused...
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 18, 2008, 04:33:29 PM
Have a look here:
http://www.groupdiy.com/index.php?topic=14805.0

That would be AC but as the thread indicates, the lamp doesn't care.

My guess would be that you're killing the resistor (though it may not be visible) and it is acting like a wire...loosing its resistance.  I could be wrong though.

You should definitely get a bigger resistor on there.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 18, 2008, 04:37:14 PM
Here is Jakob's original post:

http://www.groupdiy.com/index.php?topic=275.0
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 05:52:39 PM
Ok, I'll check this out...

So, in doing the calibration, I used the 2 videos from Mnats - totally RAWK!  Piece of cake, and it's never been easier.  These Rev D's sound much better than the G1176's, no hum problems, loooooads of level.

However, the 3rd video is not up yet, so I used the doc that I found from Nimbleswitch for Adjusting Gain Reduction.  I found that after setting level, I couldn't get the meter to show -10dB of GR, it was always still under.  I swapped the 2k trimpot with a 5k and it worked great.  I'm assuming that this is ok?  I then had to readjust meter zero and null for the initial 0v settings. 

Thanks again!
Sig
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 06:30:41 PM
Ok, so I don't have any 120 ohm 2W resistors - all I had were 1.1k 2W, so I put 4 of them in parallel which gave me about 280 ohms, close to where it should be.  The voltage at the meter light is 8.1v, making it a little dim, but it actually looks pretty cool that way.  But DAMN, those suckers get HOT!!  Is this gonna be ok to run like this?  I mean, it's hotter than the heat sink...

Thanks,
Sig
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 18, 2008, 06:36:25 PM
Mine get pretty hot.

You have to remember that the resistor is taking the excess energy and releasing it as heat, so if you're dropping 30v down to 8v...that's a fair bit of heat.

Keep in mind I only *think* I know what I am talking about.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 18, 2008, 06:40:45 PM
Ya, I pretty much don't even think I know what I'm talking about most of the time.  :D  I'll leave it for now and watch it, see what happens, fry some eggs if I get hungry.

So, it feels to me like I have a lot of level in and out of this thing.  I think I'll wait til Mnats has that last video up before I close these guys up and put them away.  The calibration went so well with his videos, then with that document for the last step I felt like I was wrecking it again...

Thanks for the help,
Sig
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on November 18, 2008, 06:44:05 PM
Excellent work!

I need to build a rev D myself...it's ironic that I haven't yet when I'm surrounded by boxes of attenuators, transformers and parts.  :)

Mike
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on November 18, 2008, 09:54:47 PM
Hey Sig,

What I've done in my 1176 VU's light, was put an extra small transformer (220 to 12V) with 2VA (that costs around €3), a couple of diodes to rectify and a 1000uF cap. I know, I know... maybe that is a little bit only to light up the VU, but I'm always a little bit affraid of wiring the lamp directly to the secondary of the toroidal... the lamp is small, but 12V with 1.3W gives you around of 0,11A of consuption... is not too much, but, with some resistors like you did or some Zenner Diodes the things got really hot, hehehehehe... I really like to separate the things ;) althrough you have one incovennience... the light's flickering made by the Toroidal's AC voltage (if you have wired directly to the trafo's secondary)  :-\ in the "studio's darkness" you need a steady light, one that will not flicker at all! makes a lot of difference when you pass hours looking at those things :)

Hey Mike, talking about the transformers! I ordered you a EA5002 Output Trafo a few minutes ago  ;D

Cheers

Eddie ;D
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 26, 2008, 01:20:18 AM
Ya...overkill dude haha.  I think with those resistors I've put in, things are great so I'll just leave it at that.

However, I have now done the calibration and everything is perfect, no hums, no crap - the Mallory T-pads are a bit scratchy, but they sound vintage that way haha.

The only problem I have is that there is toooooo much level coming in.  The input is rarely over 9 o'clock with tracks coming from Pro Tools, and I usually put a trim plugin before the insert to turn it down so it's not hitting the 1176 so hard.  What can I do here to fix this?  I am using the Mallory T-pad with Cinemag ins and outs.  What might be causing this?

Otherwise, very nice units, and sooo different from my G1176's - all are good though.  I plan on doing a pair of the Rev A's and single Purple MC76, should be a nice set when they're all done.

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on November 26, 2008, 06:43:11 AM
Hey all,

I Have a question  :-\
I matched the FETs as descibed, all ok, but when I tried to select the 2N3707 with the HFE > 250... man, I bought 20 of them, NONE has HFE > 250, can you believe that? the maximum I get was 237  :( damnnn! I stuff 2 of them for the ones that need to be matched, with HFE=220 both, stuff the one with HFE=237, and I would like to know if I can stuff 2N5088 for the rest of it, because I read that they are used in the MC76, and could be used in this project version, and sure they has the HFE over 250, like 475 or more.
I need to know if I can use that, or if I dig to use those, may I need to take off the 2N3707 already stuffed?
Well... thanks a lot!

Cheers,

Eddie  ???
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on November 27, 2008, 06:45:23 AM
Helloo... could anyone help with that above?

Mako are you there?? ;)

Cheers,

Eddie  ;D
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on November 28, 2008, 11:55:46 PM
Not to step on your toes Eddie, but I'm also wondering if anyone has come across the too much level problem with the Mallory T-pad and cinemag ins and outs.

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: mnats on November 29, 2008, 07:02:25 AM
Helloo... could anyone help with that above?

Mako are you there?? ;)
I don't get it - do you want permission to do what I suggest on my Rev D page?
Quote from: Rev D Page
Q7 through Q10 must be selected for an hFE of 250 or above. Additional transistor footprints have also been provided to allow for the substitution of alternate devices for Q7-Q10 in the Gain Reduction Control Amplifier such as the 2N5088 used in the Purple Audio MC76.
may I need to take off the 2N3707 already stuffed?
You will have a hard time putting in the alternate transistors if you don't.
Not to step on your toes Eddie, but I'm also wondering if anyone has come across the too much level problem with the Mallory T-pad and cinemag ins and outs.
What is the ratio of the Cinemag?
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on November 29, 2008, 01:24:57 PM
Hello mako,

My PCB has no alternative footprints for that transistors, only for the 2N3037... sorry for asking that, I'll swap Q5 to Q13 with 2N5088.

Thanks

Eddie  :-\
Title: Re: 1176LN Rev D DIY
Post by: mnats on November 29, 2008, 03:02:22 PM
My PCB has no alternative footprints for that transistors, only for the 2N3037... sorry for asking that, I'll swap Q5 to Q13 with 2N5088.
Every version of the Rev D boards I made has alternate base pads to accommodate the 2N5088 for Q7 to Q10.

Why do you want to swap ALL the 2N3707s?
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on November 29, 2008, 03:16:16 PM
Well now i'm confused... for Q5 to Q13 is supposed to use 2N3707, right? If I'll use 2N5088's I need to change all of them, right? ormay I leave Q5, Q12 and Q13 with 2N3707?
My basic question is need I to change all of the 2N3707 with 2N5088, or only the Q7 to Q10???

Sorry boring you mako...

Eddie  :-\
Title: Re: 1176LN Rev D DIY
Post by: mnats on November 30, 2008, 03:22:20 PM
Well now i'm confused... for Q5 to Q13 is supposed to use 2N3707, right? If I'll use 2N5088's I need to change all of them, right? ormay I leave Q5, Q12 and Q13 with 2N3707?
My basic question is need I to change all of the 2N3707 with 2N5088, or only the Q7 to Q10???

Sorry boring you mako...
You're not boring me as much as frustrating me. While English might not be your first language you are obviously fluent enough to understand what I've already written on my Rev D page and work out the rest by yourself...
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on November 30, 2008, 05:53:01 PM
I Used a 220 ohm 5 watt resistor on mine from the secondary to power the Sifam meter lamp. I have a 30/30 transformer. You can just use ohms law to find the exact value. No resistor burnouts or any other problems with my unit over extended long term use. Ya prolly don't need 5 watter tho. But I like overkill. :)

Can't wait to build my second one! I could really use it. Just trying to get the cash for the case and some small parts I am missing...
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on December 02, 2008, 03:01:50 AM
What is the ratio of the Cinemag?

Ahhhh, hmmmm maybe I will attempt to reverse the cinemag and see what happens.  I don't recall what I did, but I looked at some pics of finished ones and tried to copy that.  Let me look into it.

Thanks!
Sig
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 18, 2008, 03:08:59 AM
Hey all just a quick question. I tried searching and reading the thread again. But after reading Mnats site I wanted to know the correct values for these 3 resistors and if they are the same for version 1 and 2:

R15 6.8k?
R64 2.2k?
R12 920?

I just want to be sure cause after reading my notes from my first original board I may have used different values. Almost for sure on R12 I think I used 1.8k. I didn't open my old one yet to check. But I have the exact same parts and brands etc. to build my second one to keep them as close as possible. The original sounds unreal but just wanna keep them as close as possible for drum buss use as a pair etc. I'm also going to calibrate them both with the same input signal simultaneously etc. to match them. Been dieing to have 2 since I built the first one. It's my Christmas present to me! lol. :) :) I got my Girlfriend a video game for Christmas to keep her busy while I tinker around...

Also I was thinking about making the stereo link box. Anyone ever make one? But truthfully I typically don't use buss linking all the time on compressors... But would be a good thing to have. I saw the connections where the cable should output to the second compressor.

And everyone here have a great Holiday!

Thanks,
John
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 18, 2008, 04:23:22 AM
Well I think I answered my questions already that these are the correct values. I just gotta open up my other one when I go to calibrate them to double check. Sorry been a while since I made my first compressor hehe. Maybe I just got a bit paranoid.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 22, 2008, 09:45:51 PM
Samplegod I used all 3708 transistors instead of 3707's all passed hfe except maybe 1 out of 50... This was mentioned earlier in the thread. If I remember correctly mine compressed even without R44 in the circuit. I use 50 VA 30/30's to power this project. Only $20 bucks at Avel Lindberg. (If you buy 2) I think I could power a Christmas tree with the extra juice from the secondaries...
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 22, 2008, 10:18:50 PM
Hey Stagefright... mine is compressing zilch... :(:(:(
I changed the transistors for 5088's , but nothing happens so far... when I stuck the jumper for R44, the meter falls down from the "0"... I think I wired all correctly, the meter and ratio boards from hailball, follow the instructions, take the original schematic to wire the output trafo... don't know, I'm still searching...
It's the 4th 1176 i build, all the 3 before are running... this is my first REV D, so far, not working :(
My voltages are around 28,2 for the 30V rail and -8,6 for the -10V rail, could this cause any bad behaviour? are they sufficient? I'm using 25-0-25 from Talema... it's supposed to work... well, let me see

Cheers,

Eddie  :-\
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 22, 2008, 11:16:54 PM
My power transformer is overkill. Yours should be ok. I'll check some voltages on mine in a sec... I have number 2 on the bench.

When you install R44 your meter will change! Then you have to follow the adjustment procedure. I will check my rail voltages and report back in a bit...
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 22, 2008, 11:24:24 PM
Can you take a few close up pictures of the board and wiring and post them?

I know this has helped a few people in the past.

I would also be sure to check your trimmers and also check your transistor data sheets against the schematic.

Mike
Title: Re: 1176LN Rev D DIY
Post by: khstudio on December 22, 2008, 11:31:14 PM
I'm finishing up my REV D unit & have a question:

The parts list calls for a standard POT for the "ATTACK" ... without an ON-OFF Switch.

OK, How can you follow the "Calibration" Procedure without the Attack switch???

Is it not needed on the MNATs Version? Or, should it be added?


Thanks
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 22, 2008, 11:34:23 PM
9.94 neg and 29.84 positive. I don't think that is your problem tho. Did you check every resistor with a dmm before installing? Also pull the board and check carefully with a magnifying glass for solder bridges. Altho this board is very high quality it is still possible. And triple check wiring from the board to the switches etc. Soldering the board is easy but takes quite a while to wire up the whole project. Especially the switches. Do you have the bypass switch correctly wired? Do you have it on the pot or the switch bank? Also did you use rotaries or the push buttons?

Just a few things I could think of...
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 22, 2008, 11:38:22 PM
I used the off switch on the second push button bank as compression off on mine. Just take the wires there and use that as the switch. I have a combo eic jack/fuse/power switch on the back. Also Mnats video discusses this I believe on his site for calibration.

The attack switch is the compression off and is definitely needed and desirable ;)
But if you don't have one I believe Mnat's video shows where to jump it.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 22, 2008, 11:42:39 PM
Hey,

Yes it's addressed in calibration video 1:
http://www.geocities.com/m_natsume/1176_revision_d

You can just short pad 22 to ground.

Mike
Title: Re: 1176LN Rev D DIY
Post by: khstudio on December 23, 2008, 12:00:57 AM
Hey thanks guys!

I may have to revisit ALL of my 1176's because of this. :'(

Is the GR Disable button on the PURPLE units the same as thing? I don't have a switch on that units Attack either.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 23, 2008, 12:04:43 AM
The Purple has a true relay bypass. The real 1176 just turns off compression. Still burning fet's Also a useful color at times. :)
The schematic is offline right now... Might have compression off too.

The Purple also has a meter buffer etc. REAL nice machine...

Purple schematic is here: http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf (http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf)
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 23, 2008, 12:13:38 AM
Hey Mike my girlfriend wrapped my Hairball Audio box as a Christmas present so have to wait 'till Thursday to get my goodies LOL!
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 23, 2008, 12:26:00 AM
Awe...well hopefully you won't be disappointed!  ;)

I'm building a pair of D's right now.  Waiting on my front panels...should have them done with pictures up in about 2 weeks!

Mike
Title: Re: 1176LN Rev D DIY
Post by: khstudio on December 23, 2008, 01:11:00 AM

Is the GR Disable button on the PURPLE units the same as thing? I don't have a switch on that units Attack either.

I just looked at the Purple schematic I have & it IS the same as the switch as the original "Attack Off"... so that's cool.
That unit sounds GREAT.  ;D

After seeing were it is on the schematic I have a better grip on how to implement it on the MNAT Rev D.
... still need to check out the video too.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 23, 2008, 01:47:44 AM
Hi, I'm building mine with the pushbuttons and the 25k Lin Attack pot with SPDT switch! wired as Mike said in his specs... 22 to the center lug, the CCW to the Black on Ratio board and the other to the Green on the Ratio board also.
THe Q Bias Adj and the Null (R75) trim calibration, I did perfectly and my 1176 accept all that regulations at it should be! but after that, when I put back the jumper to get R44 on the circuit again, my meter drops to the left, and I can't regulate anything after... the tracking trimmer, I Adjust and the meter just rise a little bit just before the trimmer ends... I move the input and out put knobs and they do the same, rise and fall the output level, that's it, when it's supposed in GR mode when I start rising the input and reaching the Threshold point, start to see the compression on the meter and on the output...
When I hit the ratio board, I see the sine wave just reducing a little bit as it should be, from 4:1 to 20:1, and when I hit all the buttons the VU's indicator rise to the hard right, and this is right! because I'm putting the fet in a "bad biasing way! and this happens in my others 1176 and on the original too... I'll post some photos tomorrow! maybe this helps a lot!
Ahn.. one thing I notice is that in the MC76 schematic all the 3707 are changed by the 2N5088... but I have the 5088 only from Q7 to Q10... I'll try to swap all the 3707 with the 5088 and see what happens!

Cheers,

Eddie  :-\



Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 23, 2008, 07:51:12 AM
It may also help to install R44 with it set to the middle position for a start. And if you read Mnats site at the end of the rev D documentation it is noted that 2 resistor values on the overlay are incorrect. The correct values are listed there. Dunno if that will help any but worth a shot.

And the 3707 or 3708 will work just fine if the hfe is over 250. I wouldn't change them for no reason. The problem likely lies elsewhere.

John
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 23, 2008, 08:30:38 AM
The R15 and R64 are ok with the values... I think is not the problem with starting R44 at the middle... I change the R44 all the way up and down and no indication is shown... must be something in the GR control, 'cause when I hit the GR button, it puts pad 28 and 29 directly to the VU Meter, and it works with the jumper off (taking R44 off the circuit) with that jumper of I can regulate the "0" point, when I stuck back in position... the pointer falls down to the left and nothing happens... :(
I tried to change the 5088 by the 3707 all of them whatever hfe, and it stills the same... there's something in the circuit that is not working propertly... well... Still searching ;)

Eddie  ???
Title: Re: 1176LN Rev D DIY
Post by: khstudio on December 23, 2008, 11:05:41 AM

Is the GR Disable button on the PURPLE units the same as thing? I don't have a switch on that units Attack either.

I just looked at the Purple schematic I have & it IS the same as the switch as the original "Attack Off"... so that's cool.
That unit sounds GREAT.  ;D

After seeing were it is on the schematic I have a better grip on how to implement it on the MNAT Rev D.
... still need to check out the video too.

Opps  :-[
It seems it's the same as the "Bypass" on the G & Mnats Versions & disables the VU... so, you still have to do the "Shorting thing" like in the video to keep the VU active.

That video is helpful  ;D
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 23, 2008, 10:26:30 PM
Problem Solved!!!!

I had a bad 2N5088... and other has a bad contact... now all is working propertly!!!! I just need to check why I'm getting the input signal with the phase reversed... maybe some bad connection on the Input attenuator or with the Lundahl's input connection  :-\
But it sounds amazing, I think is more clear than my REV J one... I'll check after the Christmas in the Studio ;)
Thanks all of you!
Happy Christmas!

Eddie  ;D
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 23, 2008, 10:36:19 PM
Awesome!

Congrats Eddie.

Hope to button up my pair in the next week.

Mike
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 23, 2008, 10:48:32 PM
Thanks Mike!

Hope to see yours working too! It's a very nice comp I must say :)

I'll put some photos afterwards :)

Happy Christmas!

Eddie  ;D ;D ;D
Title: Re: 1176LN Rev D DIY
Post by: nielsk on December 23, 2008, 10:54:05 PM
Which 5088 was bad? I have one with a similar problem, I can adjust the meter with the link out an 0 the votage across R74, but when the link goes back on, the GR reading drops way down. I can bump it back up by cranking up the offset, but then it is way off 0 volts.... 
BTW, I use the attack pot / switch combo on all of mine, I do not prefer the off switch on the meter thing
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 24, 2008, 12:58:15 PM
Hey Nielsk,

Double check if your 5088 are in the right position... I'm talking about the Q7 to Q10 (Gain Reduction Stage). The boards from Mntas has a extra pad to you to put the 5088's, my first mistake was to ignore that step at the first time... and put the same way you should put the 3707... it's wrong, they has different pinout!!! the 3707 is E-C-B the 5088 is E-B-C so you need to put the 5088 in the way that you have the middle leg in the extra pad! what's happening to you maybe is what happens to mine... I adjusted easly with the jumper off, but the pointer falls down to the left when the jumper gets R44 back to the circuit.
Try that... I realize that after reading the META, then I notice a bad 5088 and other with a bad contact! fixed that, all running ;)
Happy Christmas! hope this help :)

Eddie
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 25, 2008, 03:01:54 AM
That's awesome ya fixed it Eddie. What a great Christmas present to yourself!  :P
I have my new one all done but of course after ordering 80 small parts from mouser and digikey I missed the .0047 cap... they wanted $40.00 for overnight so I stuck to ground shipping lol. Be here Monday.
Hope you enjoy it. I am using my first one right now. It gets lotsa miles and keeps on ticking.

If the phase is reversed just switch the wires. But I'm sure you already know that.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on December 25, 2008, 09:59:19 AM
Hey John, yeah, I swap the wires from the input trafo! and now it's full throtle! hehehehe...
Sorry for your cap that you forget ordering... It's very bad when that happens!
Happy Christmas for everybody!

Eddie  ;D
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 25, 2008, 04:06:08 PM
Don't worry all is not lost. My girlfriend wrapped my hairball order for stuff and got it today. Also I switched out 3 resistors on my original one and re calibrated. So needs a long "burn in" just in case ;)

I did notice tho that as in the original 1176 doc from Urei the 0 set point can drift up to 1 DB. And this is true on the clone. It does the same thing. I believe this is a temperature thing. I originally calibrated the zero with the lid off the case. This time I zeroed the meter after leaving the lid on. After all that is real world. And after running audio thru it all day it has a VERY stable 0 VU.

I would suggest running it with the lid on for several hours before a final adjustment to the 0 trimmer. I turn my stuff on WAY before a session so 10 to 18 hours is normal. So should be the calibration. But don't touch anything but the zero set. The other trimmers will hold fine. That's why the original has A hole in front to adjust 0.   
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 25, 2008, 04:08:24 PM
Missing 1 cap but close!!!!

(http://www.stagefrightrecords.com/11762.JPG)
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 25, 2008, 04:17:01 PM
And I can't imagine how much work it took Mako to make this... And to make it to work so well!

Merry Christmas Mako your super hard work is WAY appreciated! And I am sure is appreciated around the world.

John
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 25, 2008, 07:25:36 PM
Just make sure you wire it rev1 or rev 2 depending on board there are some wire differences such as Matta said in the out tranny?
Title: Could use some help on mnats rev d
Post by: etevelurblomst on January 02, 2009, 11:54:09 AM
Hey, i was hoping anyone could be a little helpfull on this one. I`ve built the mnats 1176 rev d clone, and its working and compressing etc etc, but the output from the transformer has too high impedance, so the compressor will only work if you put it in line inputs designed for high impedance, such when you put a bassgitar straight in etc..

Does someone have a good idea on what to do, im pretty sure i hooked up the trafo correctly, so maybe the fault is further down the line?



 if you put the comp. into a regular line input --  some form of positive feedback occur, going from the output and back into the circuit..

someone with a clue?? or something to do to eliminate problem sources?

Title: Re: Could use some help on mnats rev d
Post by: joe-electro on January 02, 2009, 12:12:18 PM
Hey, i was hoping anyone could be a little helpfull on this one. I`ve built the mnats 1176 rev d clone, and its working and compressing etc etc, but the output from the transformer has too high impedance, so the compressor will only work if you put it in line inputs designed for high impedance, such when you put a bassgitar straight in etc..

Does someone have a good idea on what to do, im pretty sure i hooked up the trafo correctly, so maybe the fault is further down the line?



 if you put the comp. into a regular line input --  some form of positive feedback occur, going from the output and back into the circuit..

someone with a clue?? or something to do to eliminate problem sources?



Look for bridged traces around the input transformer and output transformer.
Title: Re: 1176LN Rev D DIY
Post by: etevelurblomst on January 02, 2009, 12:15:48 PM
Could you please ellaborate? im from norway, so electronics terms in english gets me sometimes..

By bridged you mean?
Title: Re: 1176LN Rev D DIY
Post by: matta on January 02, 2009, 03:02:29 PM
Could you please ellaborate? im from norway, so electronics terms in english gets me sometimes..

By bridged you mean?

This happens when you accidentally 'short' pads together, causing a 'Bridge' between those connections. Sometimes a bit of solder accidentally joins two different parts of the circuit together. Hope that helps.

Cheers

Matt
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 02, 2009, 06:37:52 PM
Well here is a cautionary tale...

I finally got all my pieces together for my REV D V2 1176, which I've been building over 3-4 months as time/money has allowed and I was ready for the final hook-up.

I printed the schematic so had it on record along with the original schematic for the UREI Rev D and thought I was prepared for things... but...

I noticed having soldered the screw terminals on the PCB it covered up the colour coding for the output transformer... no problem! I'll just print it out as it is laid out in MNATS beautiful document, so I do and wire up accordingly...

The big moment arrives, I flip the switch BRIGHT lights and flames as R32 goes up in smoke... hmm funny, I had checked my wiring all looked good, voltages were good, what went wrong?

So I desolder it and then work backwards... but wait R32 was going to the wrong winding.... something is fishy... I open up the MNATS REV 2 document and the output transformer colours DON'T match the board... penny drops!!!!

I had BOTH the REV1 and REV2 manuals of MNATS and while I was working from the correct schematic for REV2 and the UREI one (which is great since it shows that you have to join the CT Orange and Yellow wires together if you have Ed's transformer) but the OVERLAY was REV1 which DOESN'T match up with REV2 (Mako you may want to add this to your list of changes to your REV D site in case anyone else makes the same blundering mistake!).

Oh man +1 on this Matt.  I read the first line of your post a few weeks ago and nothing else.  Turns out I did EXACTLY the same thing!

I've never seen a resistor evaporate so fast.

My new years resolution: when I see a post starting with "Well here is a cautionary tale..." I will read the whole thing  ;D

Oh well all is great now!  Will post some pics when I get my front panel.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on January 02, 2009, 06:42:42 PM
Yeah that's why I mentioned it on the previous page. I did the same thing. Don't feel bad. I didn't even get my finger off the switch and that resistor had already gone to a better place lol!
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 03, 2009, 05:02:00 PM
I have no idea how I missed all the references to this.  ;D

Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on January 04, 2009, 12:35:17 PM
Hey... I'm looking to stereo link my REV D with my other mnta's based REV F. Is this possible? need I to build another extra circuit like in the MC76? just to know... to stereo connect the REV Fs is just connect a wire  :-\ or, of course if the fets are not matched, use the easly to build UA Stereo box.
Any ideas?

Eddie ;D
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on January 04, 2009, 02:49:17 PM
The rev D is a different compressor with a class A output. I doubt they even sound the same.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on January 04, 2009, 04:29:58 PM
Yeah, you're right, they sound really different... I just asked that to be sure I can't connect 2x 1176 REV D's withou any other extra circuit... now I see if I want to connect 2 of them, need a extra circuit like the MC76  :-[

Thanks

Eddie  ;)
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on January 04, 2009, 10:15:38 PM
I posted a while back with my Rev D's and input level.  I'm using the Cinemag inputs.  Mnats hinted at turning the cinemag around so that I would be able to hit it with more level, and have it not compress so soon.  Well, I swapped one of them today (I built 2 units) and...the level in and out is identical on both units...

How is this possible, if the transformer is oriented differently in both units???  (scratches head)

How have others oriented their Cinemag CMMI 2PCA input transformers for their Rev D's?

Thanks,
Sig
Title: Re: 1176LN Rev D DIY
Post by: Siegfried Meier on January 06, 2009, 04:21:13 PM
Anyone build a Rev D with Cinemag transformers at all besides me?   :-[

Thanks,
Sig

Edit - I think the Cinemag orientation has nothing to do with the level getting in, as I've experienced - both ways sound the same, and react the same.  The units in bypass have great in and out level, I will try the 470k threshold mod and see if this corrects my issues.
Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 16, 2009, 01:41:11 PM
EDIT: duplicate information deleted
Title: Re: 1176LN Rev D DIY
Post by: mitsos on January 16, 2009, 01:42:27 PM
wow.. that's awesome! Thanks for making it simple for the rest of us!
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 16, 2009, 01:51:27 PM
You are awesome Skylar!

This is a great reference.

Mike
Title: Re: 1176LN Rev D DIY
Post by: ethervalve on January 16, 2009, 02:22:17 PM
That's amazing Skylar! What a kindly soul you are for sharing.
Title: Re: 1176LN Rev D DIY
Post by: 0dbfs on January 16, 2009, 02:35:13 PM
http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALL.pdf (http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALL.pdf)

Hey Thanks!

I'll dig into this when I start assembling my Dual-RevA. It looks like it will be an excellent reference even with the slight differences.

Cheers,
jonathan
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 16, 2009, 02:36:58 PM
Yes, please note there is some difference with the REV D V2 and A connections.  Specifically with the output transformer and the ground pad by pad 7.

Always best to check against the schematic!

Mike
Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 17, 2009, 02:45:34 AM
Yes, please note there is some difference with the REV D V2 and A connections.  Specifically with the output transformer and the ground pad by pad 7.

Always best to check against the schematic!

Mike

Yes, I should add a disclaimer:

My wiring guide was made while building one of mnats' original rev D boards, so if you have a newer board, there will be some slight differences!

But if you're following the schematic/new board layout like good boys and girls, you can easily note these differences and move forward!
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on January 17, 2009, 02:47:03 AM
This may be a long shot Siegfried but I always put a couple pieces of wire under the input transformer to space it up from the board slightly before soldering. The reason for this is so when the solder flows to the upper side of the board it will prevent it from touching the can of the transformer on the underside. Especially if too much solder is used. I doubt that is your problem but is a good measure to use anyway...

John
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 17, 2009, 09:59:48 PM
Well I assume there are some people like me who never get sick of seeing finished projects so here goes...

Disclaimer: Sorry these pics suck...I am the worst photographer on the planet. 

Here are a pair of beauties a built over the holidays.

Front of Both
(http://farm4.static.flickr.com/3534/3205487582_cc5b781cba_o.jpg)

VU and Pushbuttons
(http://farm4.static.flickr.com/3400/3205487728_b319d2b1ff_o.jpg)

Inside one unit...they both look the same inside  ;)
(http://farm4.static.flickr.com/3464/3205487836_14926b7e4e_o.jpg)

Rear of VU showing pushbutton mounting discussed in other thread
(http://farm4.static.flickr.com/3394/3205487656_aa655ceff2_o.jpg)

I had a great time...no major issues.

Notes:
-  I have RCA connectors on the back for eventual stereo connection.  I will deal with this later.
-  Put the "0 adjust" multi turn put up near the front panel using a little bracket...adjustable through a hole in the front like the original.
-  Mounting the pushbuttons with a set screw and a little J-B Weld seems solid.  Very solid.
-  GR Disable is on the attack knob like the original.
-  Both units are reading a THD+N of 0.036% following the Purple Audio procedure.  I believe this to be good.
-  One of the unit's ratios are a little high (around 6.5, 12, 15, 30 if I recall).  The other unit's ratios are correct.  I'll look into this in a bit...too tired right now.
- Used Skylar's input grounding technique...both units are dead quiet.
- I mounted my on board trimmers backwards...which is fine...just have to turn the trimmers in the opposite direction the calibration manuals say...but you haven't built yours yet...go the opposite way I did ;)

I think that's it!

I'm lending them to a local studio for a few weeks to get some feedback.  They have a pair of original D's and will give them a good work and provide a better review than I could give.

Thanks Mako and everyone who chips in on the thread!

Mike
Title: Re: 1176LN Rev D DIY
Post by: Chrome Heart on January 17, 2009, 10:06:56 PM
Well I assume there are some people like me who never get sick of seeing finished projects so here goes...

Disclaimer: Sorry these pics suck...I am the worst photographer on the planet. 

Here are a pair of beauties a built over the holidays.

Front of Both
(http://farm4.static.flickr.com/3534/3205487582_cc5b781cba_o.jpg)

VU and Pushbuttons
(http://farm4.static.flickr.com/3400/3205487728_b319d2b1ff_o.jpg)

Inside one unit...they both look the same inside  ;)
(http://farm4.static.flickr.com/3464/3205487836_14926b7e4e_o.jpg)

Rear of VU showing pushbutton mounting discussed in other thread
(http://farm4.static.flickr.com/3394/3205487656_aa655ceff2_o.jpg)

I had a great time...no major issues.

Notes:
-  I have RCA connectors on the back for eventual stereo connection.  I will deal with this later.
-  Put the "0 adjust" multi turn put up near the front panel using a little bracket...adjustable through a hole in the front like the original.
-  Mounting the pushbuttons with a set screw and a little J-B Weld seems solid.  Very solid.
-  GR Disable is on the attack knob like the original.
-  Both units are reading a THD+N of 0.036% following the Purple Audio procedure.  I believe this to be good.
-  One of the unit's ratios are a little high (around 6.5, 12, 15, 30 if I recall).  The other unit's ratios are correct.  I'll look into this in a bit...too tired right now.
- Used Skylar's input grounding technique...both units are dead quiet.

I think that's it!

I'm lending them to a local studio for a few weeks to get some feedback.  They have a pair of original D's and will give them a good work and provide a better review than I could give.

Thanks Mako and everyone who chips in on the thread!

Mike


Very Nice. 8)
Title: Re: 1176LN Rev D DIY
Post by: mitsos on January 17, 2009, 10:22:44 PM
wow... that is some beeuutiful work. Very nice.

question... what did you use for the GR OFF? A pot with a built-in switch? Is this something available from mouser?
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 17, 2009, 10:30:16 PM
Thanks!

Yes sir...pot with a SPDT switch in the fully CCW position.

Mouser part # 315-2415F-25K

Mike
Title: Re: 1176LN Rev D DIY
Post by: mitsos on January 17, 2009, 11:03:16 PM
thank you!
Title: Re: 1176LN Rev D DIY
Post by: kato on January 18, 2009, 07:23:15 AM
I never tire of seeing finished units.
Beautiful work echo north!
Title: Re: 1176LN Rev D DIY
Post by: onlymeeee on January 18, 2009, 11:22:34 AM
Nice build Mike.
What pot did you use for the zero adjust? Did you make the case yourself? How did you do the writing? Lazer engraved?
Title: Re: 1176LN Rev D DIY
Post by: orangerec on January 18, 2009, 01:56:02 PM
Nice pair Echo North  ;D
Also, thanks for the JB Weld tip, I can't believe how strong that stuff is. I used it on mounting the pushbuttons and purposely tried to break them but I think you would destroy the switches before breaking the cold weld. Nice meters, are they the Modutecs floating around here or Sifams?
Title: Re: 1176LN Rev D DIY
Post by: Neeno on January 18, 2009, 02:26:27 PM
Hi Skylar !
Thank for the nice diagram...

NOTE: there is something I don't get on the attenuator wiring. Double check it.

The input (hot) wire is connected to the wrong spot. In fact following puple schematic it should go to the wiper of the 1st deck, connected to the 620R resistor and not where the two resistor are connected togheter.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 18, 2009, 02:44:06 PM
Quote from: onlymeeee
Nice build Mike.
What pot did you use for the zero adjust? Did you make the case yourself? How did you do the writing? Lazer engraved?
Thanks!

Zero adjust: Digikey #SP534-2.0K-ND
I just used the cheapest panel mount multi turn pot I could find.  This one was $13.  Works nice.

Case:
Front Panel Express.  Spendy but high quality.  They are also just down the street so no shipping charges ;)

Quote from: orangerec
Also, thanks for the JB Weld tip, I can't believe how strong that stuff is. I used it on mounting the pushbuttons and purposely tried to break them but I think you would destroy the switches before breaking the cold weld. Nice meters, are they the Modutecs floating around here or Sifams?

Ha!  I did the same thing!  I was convinced the switches would fly out of their chassis before the weld let go.  I think the key is to not use more then you need and let it dry for a good 48 hours.

It's a Sifam meter but I would have used Modutec if I hadn't already had the hole cut when I saw them.  The original uses Modutec (I think) and they are true VU (I think) so less lag than the Sifams.

Mike
Title: Re: 1176LN Rev D DIY
Post by: onlymeeee on January 18, 2009, 03:29:48 PM
13 dollars is a bit more than I'd like to spend really!
How do you think a regular (linear?) pot would work?

As far as I know, it's the other way round. The sifams have less overshoot than the modutecs sold on here.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 18, 2009, 03:45:45 PM
A regular linear pot would work fine, it would just be harder to dial in "0".  Having 10 turns gives you a lot more accuracy...but at 10X the price...so I understand where you are coming from.

Never used a Modutec,  I'm just interested because they should be like the originals.  I'm also interested in the Hoyt's that Purple uses.

Although the Sifams are a nice meter. 

I'm far from an expert on meters.

Mke
Title: Re: 1176LN Rev D DIY
Post by: onlymeeee on January 18, 2009, 10:36:44 PM
Yeh I think I'll try the normal pot and see if it works well enough.  Just thinking off the top my head, maybe there's a way of making a pot less sensitive by putting a resistor in parallel? eg. a 5k pot with a 3k resistor in parallel?)

Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 19, 2009, 12:40:09 PM
Hi Skylar !
Thank for the nice diagram...

NOTE: there is something I don't get on the attenuator wiring. Double check it.

The input (hot) wire is connected to the wrong spot. In fact following puple schematic it should go to the wiper of the 1st deck, connected to the 620R resistor and not where the two resistor are connected togheter.


HA! you're right. I think I remember changing this, but I guess I did not update the diagram.

I'll fix this in the PDF. Thanks!
Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 19, 2009, 12:54:03 PM
EDIT: duplicate information deleted
Title: Re: 1176LN Rev D DIY
Post by: Neeno on January 19, 2009, 02:28:06 PM
You're fast !
But it's still wrong... the wire goes to the wiper (connected to the resistor leg)
 :D


Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 19, 2009, 04:00:22 PM
!!!!!!!!!!!!!!!!!!!!!!!!!

That's what happens when you work too fast.

But it's still wrong... the wire goes to the wiper (connected to the resistor leg)
 :D

Exactly what I meant to do, but somehow that's not what I did!
I'm as confused as you are on why I flubbed it again.

Okay, one more try--thanks for being my editor Neeno!
Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 19, 2009, 04:08:55 PM
Okay, it's updated again...see original update post.
Title: Re: 1176LN Rev D DIY
Post by: Neeno on January 19, 2009, 06:15:50 PM
Hahahaha !
Now it's right.

Cheers
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on January 30, 2009, 04:16:55 PM
I tried loading Skylar's wiring document and it says the file is damaged and cannot be repaired. Anyone else having a problem?

John
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 30, 2009, 04:20:15 PM
No sir.  Fine here.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Skylar on January 30, 2009, 05:02:06 PM
Have you tried right-clicking > save as...
Then save to desktop and open in Acrobat (not your browser)?

If it gives you that error when opening in Acrobat, I would suggest updating Acrobat if possible.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on January 30, 2009, 05:18:54 PM
OOps that was it. I noticed it worked fine on my other station... Thanks Guys!!

John
Title: Re: 1176LN Rev D DIY
Post by: JdJ on January 31, 2009, 10:55:05 AM
Hey all-

Just had to recalibrate my D's (rev1) as the meters (Sifam AL19) had drifted way up to +3 on both channels of my dual mono and on one channel, occasionally didn't seem to be registering GR at all.  No big deal really, set out to re-calibrate but I was using in-the-box metering for the gain reduction measurements etc, and I can not for the life of me get the on-board meters to read 10db of gain reduction?!  I really had to futz with the 0 adjust and the tracking to even get it close.  (I think I recall it being normal for the meter to drop away from zero once the R44 trimmer is re-inserted (after Q Bias & Null adjust)).  I'm getting about -6db on the Sifam with -10db on my Rosetta meters and -10db in the box...  Is there a scale issue with this project on the Sifam meters?  It's not really a BIG deal really,  would just be nice if they were more accurate...

Cheers

J
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on February 01, 2009, 03:19:30 PM
There is no problem with the meter scales. The meter CAN drift up somewhat after extended use as said in the original 1176 manual. That is normal. I calibrate after the unit has been on a few hours. Just follow the video calibration procedures. Then insert R44. then trim the meter as follows:

(This was posted earlier in the thread by Bri but explains it better than I can)

So when you're sure about your Qbias, and have then done the Zero meter, 0volts across R74 step....
Here's an outline of my tracking adjust method...maybe it will help:


R44 in
GRmode(20:1)
Your controls set for the 10db swing(10db of GR)
Your source signal coming through...being compressed.

Now, adjust your meter needle to -10VU using the R44 "tracking adjust" trimmer(reflecting the 10db of reduction).

Now, mute your source signal(or short pad 22 to ground), and adjust the needle back up to 0VU using the "0 Set"(R71) trimmer.

Now un-mute your source signal again(or un-short pad 22), and readjust R44 trimmer so the meter needle again shows the 10db of gain reduction(-10VU).

Mute the source signal(or short the 22 pad), and again use the "0 Set"(R71) trimmer to adjust the meter needle back to 0VU.


You should see a slight bit of change(for the better) after each adjustment cycle.

So, repeat this back and forth adjustment procedure until the meter finally holds it's adjustments...
i.e., the meter needle will eventually hold at -10VU when you have the source signal present, and then go back to 0VU when you mute the source signal(or short pad 22 to ground).
Getting to this point usually requires many repetitions of that adjustment cycle.
Title: Re: 1176LN Rev D DIY
Post by: JdJ on February 02, 2009, 09:46:27 AM
There is no problem with the meter scales. The meter CAN drift up somewhat after extended use as said in the original 1176 manual. That is normal. I calibrate after the unit has been on a few hours. Just follow the video calibration procedures. Then insert R44. then trim the meter as follows:

(This was posted earlier in the thread by another member but explains it better than I can)

So when you're sure about your Qbias, and have then done the Zero meter, 0volts across R74 step....
Here's an outline of my tracking adjust method...maybe it will help:


R44 in
GRmode(20:1)
Your controls set for the 10db swing(10db of GR)
Your source signal coming through...being compressed.

Now, adjust your meter needle to -10VU using the R44 "tracking adjust" trimmer(reflecting the 10db of reduction).

Now, mute your source signal(or short pad 22 to ground), and adjust the needle back up to 0VU using the "0 Set"(R71) trimmer.

Now un-mute your source signal again(or un-short pad 22), and readjust R44 trimmer so the meter needle again shows the 10db of gain reduction(-10VU).

Mute the source signal(or short the 22 pad), and again use the "0 Set"(R71) trimmer to adjust the meter needle back to 0VU.


You should see a slight bit of change(for the better) after each adjustment cycle.

So, repeat this back and forth adjustment procedure until the meter finally holds it's adjustments...
i.e., the meter needle will eventually hold at -10VU when you have the source signal present, and then go back to 0VU when you mute the source signal(or short pad 22 to ground).
Getting to this point usually requires many repetitions of that adjustment cycle.


That's precisely what I did - since the tracking and zero adjust interact so much, I almost used them to achieve the others intent with pretty good results. But it still only reads -6db on the meter. If you switch from 20:1 to 4:1 without touching the other controls should you see more gain reduction at the output? 

Thanks for responding SF


Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on February 08, 2009, 07:12:14 AM
When you switch ratios the input pot needs to be adjusted to get the same gain reduction. Sounds like you may have an incorrect resistor value somewhere. I would check that. It's easy to swap a K for an R so to speak.

I'm wiring my rev D right now. Wish me luck! ;)
Title: Re: 1176LN Rev D DIY
Post by: luis on February 10, 2009, 01:52:52 PM


Can someone help-me wiring the EA-5002 Output transformer?

According to the mnats info:
 "The EA-5002 will also fit right into a 1U rack case without any modifications. The color code is the same as the Cinemag except for the output secondaries. The EA-5002 has two secondary output windings - four wires like the original - that are ordinarily connected in series. The Cinemag is connected internally, so it has only two wires at the output."

After connecting the wires to the board (easy since the colors are identified on the board) there are four wires remaining to connect, As far as I understand, 2 are going to the output pot, and the other 2 should be connected together.
Can you tell me what wires are going to the output pot?

There is also a ground wire. Where should be this wire connected? Anywhere on the chassis or should I solder it together with the other ground cables in a "star ground scheme"?


I´m also having trouble with the Atran input TX, even having red the explanation mnats gave in this thread due to my poor English understand, can you help me with the links/jumpers that this transformer need to be soldered?
Thank you,
Luis
Title: Re: 1176LN Rev D DIY
Post by: JdJ on February 10, 2009, 02:44:21 PM


Can someone help-me wiring the EA-5002 Output transformer?

According to the mnats info:
 "The EA-5002 will also fit right into a 1U rack case without any modifications. The color code is the same as the Cinemag except for the output secondaries. The EA-5002 has two secondary output windings - four wires like the original - that are ordinarily connected in series. The Cinemag is connected internally, so it has only two wires at the output."

After connecting the wires to the board (easy since the colors are identified on the board) there are four wires remaining to connect, As far as I understand, 2 are going to the output pot, and the other 2 should be connected together.
Can you tell me what wires are going to the output pot?

There is also a ground wire. Where should be this wire connected? Anywhere on the chassis or should I solder it together with the other ground cables in a "star ground scheme"?


I´m also having trouble with the Atran input TX, even having red the explanation mnats gave in this thread due to my poor English understand, can you help me with the links/jumpers that this transformer need to be soldered?
Thank you,
Luis


Sorry Luis-

I don't have the schematic or my unit in front of me.  did you see Skylar's wiring guide?

http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv3.pdf (http://www.equinoxsystems.net/DIY/SG-1176-RevD-Wiring_ALLv3.pdf)

Hope it helps

Good luck SF!!

Josh
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on February 10, 2009, 03:53:48 PM
On the 5002 connect the orange and yellow together (by themselves not connected to board or anything). Then connect the red and blue to your output. The schematic for that transformer is here http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf (http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf)

I didn't even hook the ground wire up but I guess you can hook it to star ground if you want. Or circuit ground.

It's just like the original wires. Mnats mentions this on his Rev D page toward the bottom.

Mines in the rack done and squeezing. :) finished it yesterday morning. Sounds exactly like my first one. Gonna rig up an 1176SA stereo adapter and see what they sound like on drum overheads. And may match up a pair of Q1's for them.

John
Title: Re: 1176LN Rev D DIY
Post by: luis on February 10, 2009, 04:37:55 PM
Thank for all your help!

I have Skylar files, but he used the cinemag output tx, not EA-5002.

John: I was reading the manual, but i didn´t finish.. so I tought that was just the manual without any schematic.. I´m so dumb! :-[

Thank you all, once again!
Luis
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on February 10, 2009, 05:23:49 PM
Yeah it's a great idea to read the entire original manual. Lots of cool stuff in there and original scanned historical stuff. It's a great read. And there is a TON of other tests you can do if you have the equipment.

John
Title: Re: 1176LN Rev D DIY
Post by: rodabod on February 21, 2009, 12:00:12 PM
Has anyone tried, or does anyone have an opinion on running the 1176 from a JLM 48V supply?

Any comments? I've not used the JLM supply, but I assume it should be decent enough if it is used for mic preamps too.
Title: Re: 1176LN Rev D DIY
Post by: rodabod on March 02, 2009, 12:20:55 PM
Has anyone tried, or does anyone have an opinion on running the 1176 from a JLM 48V supply?

Any comments? I've not used the JLM supply, but I assume it should be decent enough if it is used for mic preamps too.

Bump. Has anyone tried this? Or have any reason to doubt it? I will try, but if anyone has any opinions, I'd be glad to hear them.

Roddy
Title: Re: 1176LN Rev D DIY
Post by: luis on March 03, 2009, 06:31:01 PM
I´m finish my pushbutton version, but I can´t find a 25K Linear Pot with SPDT here. The more close I could buy was a 22k but it has 6 solder lugs instead of 3 like the recommended one.

Can someone confirm if this would work, and if possible, help wiring it?

Thank you all,
Luis
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on March 04, 2009, 02:21:38 AM
It should work.  Sounds like you have a DPDT.

You need to know how the 6 lugs are connected. If they are lined up like the pushbutton switches the 2 middle lugs are probably common.  In that case, refer to the part in my instructions where I show how to wire the bypass to the the pushbutton switch.  You'll want to use the continuity tester on your multimeter to figure out which lugs the common is connected to in which position.  Or refer to a datasheet if you have one.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: jakearoo on March 09, 2009, 01:31:19 PM
Where does pad 4 of the meter go? I know it needs power, but can't get my head around it.
Title: Re: 1176LN Rev D DIY
Post by: luis on March 13, 2009, 06:35:34 PM
It should work.  Sounds like you have a DPDT.

You need to know how the 6 lugs are connected. If they are lined up like the pushbutton switches the 2 middle lugs are probably common.  In that case, refer to the part in my instructions where I show how to wire the bypass to the the pushbutton switch.  You'll want to use the continuity tester on your multimeter to figure out which lugs the common is connected to in which position.  Or refer to a datasheet if you have one.

Thanks,

Mike

Thanks Mike,

I think I will not use this pot that i bought. It just feels cheap and I cannot find the datasheet.  Does anyone have a spare one of these switch that could sell-me? It seems impossbile to find in Europe, and to buy from mouser, its really expensive (Switch + shipping + Possible Customs).

Regarding the pushbuttons, I don´t understand how the power button (in the Pushbutton version) is wired. Can someone help-me? For what I understand the hot wire is runnign in the button? Looks dangerous! ;D
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on March 13, 2009, 09:11:24 PM
Hello Luis ;)

The OFF pushbuttom is wired the way to put the unit off when pressed, so when you press another buttom like GR buttom, the unit power on! and only power off when you press the OFF buttom? can you see that? the 4 buttoms function in oposition, get it?
About the 25K with SPDT... I really bought mine from Mouser... here in Portugal... forget it.

Cheers,

Eddie ;D
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on March 14, 2009, 02:47:17 AM
rodabod why would you want to use a JLM supply? I would save that for another project. everything is on board ya just need a toroid. And will be whisper quiet.

jakearoo I'm not sure what ya mean by pad 4 of the meter. Do you have push button or rotary switches? I never made a rotary one.

And yeah the original had full AC wired to the front panel. I put switched and fused IEC jacks on the back panel and use the "off" button on the front panel to turn off gain reduction. I didn't use the attack pot with switch on all mine cause I didn't know where to get one at the time. Now I like it that way.  ;D

Mike from Hairball gives instructions for that and other options in his great instruction kit that comes with the switch boards.

My only problem was I was short 2 1176's tracking a couple weeks ago! It never ends does it??!!

John
Title: Re: 1176LN Rev D DIY
Post by: spica on March 22, 2009, 02:57:12 AM
Jakearoo,

I connected Pad 4 on the Meter board to Pad 4 on the Ratio board on mine.  I think that is correct - mine seems to work anyway... except...

My Ratio switch seems to work backwards - has anyone experienced this?  Going clockwise I get 20:1, 12:1, 8:1, 4:1, 1:1, 1:1...  I'm using the rotary switch from Kato's parts list with Mnat's board.

I re-checked my wiring and everything seems to be correct.  Am I missing something? 

Thanks.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on March 22, 2009, 03:32:40 AM
My Ratio switch seems to work backwards - has anyone experienced this?  Going clockwise I get 20:1, 12:1, 8:1, 4:1, 1:1, 1:1...  I'm using the rotary switch from Kato's parts list with Mnat's board.

How are you determining ratio's? 

If you're just looking at the GR on a meter, lower ratios (4:1) tend to show more GR on a meter then higher ratios (20:1).  The amount of GR is not the same as the GR ratio.  If you haven't yet, check out gwans fabulous page on measuring GR ratios:
http://www.axtsystems.com/index.php?view=article&catid=34%3A1176ln&id=54%3A1176lnratios&option=com_content&Itemid=62

If you already know all this, my apologies in advance ;)

Mike

Title: Re: 1176LN Rev D DIY
Post by: spica on March 22, 2009, 05:15:30 AM
Thanks, Mike.

My thinking on the GR was wrong - didn't occur to me that the threshold changes with each ratio although it is something I know I've read in the thread before.  It's been a long day of breathing solder fumes:)

Has anyone implemented Slam Mode with the Lorin switch?  Not sure there is an easy way to do it, might have to use the Alpha per Mnat's pictorial instead.  Looks like that will be tomorrow's project.



Title: Re: 1176LN Rev D DIY
Post by: rodabod on March 22, 2009, 07:07:41 AM
rodabod why would you want to use a JLM supply? I would save that for another project. everything is on board ya just need a toroid. And will be whisper quiet.

Thanks. I just thought it would keep things simple as I probably won't use my BAs at the same time as the 1176. I could skip most of the PSU section bar a bit of filtering.

But you probably have a point... I maybe should just go with a standard design.
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on March 30, 2009, 06:46:01 PM
hello,
I have just powered my unit up.
I got the BEAUTIFUL KIT from hairball audio: Trafos, ratio switches Input PAD.
the attack pot is the suggest one from moused with DPDT.
I have wired my unit according to SKYLAR instructions (apart from output trafo which the color coding doesn not match what I have here) and used hairball instructions on how to wire the attack pot up.
i get (even before line up) 46dB of gain before it peaks, i am monitoring using a Neutrik A1 meter (nice piece of kit)
everything seems to be working fine BUT...
I get gain reduction even when the attack pot is on "OFF"
I have checked the usual suspects : wiring, loose connections, dry joints... even if I have left the kattle on....(sorry kinda english humor)

what else am I missing?

any tips will be much appreciated.


Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: joe-electro on March 30, 2009, 06:53:32 PM
Sounds like a problem wiring the switch on the back of the attack pot.  Make sure the wire referred to as #22 is being switched to ground when the switch is in the "off" position.

--Joe


hello,
I have just powered my unit up.
I got the BEAUTIFUL KIT from hairball audio: Trafos, ratio switches Input PAD.
the attack pot is the suggest one from moused with DPDT.
I have wired my unit according to SKYLAR instructions (apart from output trafo which the color coding doesn not match what I have here) and used hairball instructions on how to wire the attack pot up.
i get (even before line up) 46dB of gain before it peaks, i am monitoring using a Neutrik A1 meter (nice piece of kit)
everything seems to be working fine BUT...
I get gain reduction even when the attack pot is on "OFF"
I have checked the usual suspects : wiring, loose connections, dry joints... even if I have left the kattle on....(sorry kinda english humor)

what else am I missing?

any tips will be much appreciated.


Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on March 30, 2009, 06:58:46 PM
Quote from: Joe
Sounds like a problem wiring the switch on the back of the attack pot.  Make sure the wire referred to as #22 is being switched to ground when the switch is in the "off" position.

--Joe


Quote from: mata_haze on Today at 06:46:01 pm
hello,
I have just powered my unit up.
I got the BEAUTIFUL KIT from hairball audio: Trafos, ratio switches Input PAD.
the attack pot is the suggest one from moused with DPDT.
I have wired my unit according to SKYLAR instructions (apart from output trafo which the color coding doesn not match what I have here) and used hairball instructions on how to wire the attack pot up.
i get (even before line up) 46dB of gain before it peaks, i am monitoring using a Neutrik A1 meter (nice piece of kit)
everything seems to be working fine BUT...
I get gain reduction even when the attack pot is on "OFF"
I have checked the usual suspects : wiring, loose connections, dry joints... even if I have left the kattle on....(sorry kinda english humor)

what else am I missing?

any tips will be much appreciated.


Best,
Mattia.



If i do a continuity test between the common of the switch and ground when in OFF position it's an open circuit hence it's not shorting pin 22 to ground...
where is this missing ground then....???

Title: Re: 1176LN Rev D DIY
Post by: mata_haze on March 30, 2009, 07:06:48 PM
Again...
is "Shield from 22 (BLK)" on the ratio board (provided by Hairball) meant to be connected to ground at all?

tha seems to cure it but i am not sure if it is meant to be like that..


Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: joe-electro on March 30, 2009, 07:33:47 PM
Yes, that's where they got the grounding point in the original.  Weird but true.

Joe


Again...
is "Shield from 22 (BLK)" on the ratio board (provided by Hairball) meant to be connected to ground at all?

tha seems to cure it but i am not sure if it is meant to be like that..


Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on March 30, 2009, 07:39:58 PM
Yeah if you look at Skylars diagram it has grn and blk on the ratio board. The hairball audio boards also say blk and grn. (In parenthesis) Same thing

John
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on March 30, 2009, 07:44:43 PM
There is a step by step guide for this about 2/3 down Mako's J page:
http://www.geocities.com/m_natsume/1176-wiring-pushbutton.html

The only difference is to remember when he says "solder 22/Grn/Blk to the meter board" it will be the attack pot switch for you.

Mike
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on March 30, 2009, 07:54:31 PM
YOU GUYS ROCK!

Thank you very much!

Mattia.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on March 31, 2009, 09:25:54 PM
Cool ya got it working? Congrats! I'm working on making a 2-rev D right now. They sound great on everything.

John
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 01, 2009, 10:11:05 AM
I have used it on female vocals last night in during mix session.
I am speechless..it does have a very unique sound (compared to G1176 or New UAs) and it's very very pleasant.

Very impressed.
I will post pictures soon ( I have used it with no cover on nor meter so it does not look good as yet).

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: RedNoise on April 07, 2009, 06:06:58 AM
Hi , actualy finalizing my revD and A , I would like to power 4 (2 x RevD and 2 x revA) with the same psu.
I know this is a dumb question , but :
Do you think I have to change components in Mnats external PSU to power my four 1176?
Maybe T versions of the LM3xx , or 1A versions of the 1N4007?
By advance , thanks.
T.
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 10, 2009, 02:35:25 PM
Hi everybody just finishing my first unit,
I did the full calibration procedure today (although I have tested it in the studio the other day without calibrating it...I was too curious!) and althought everything went fine I have a problem:

there is a self oscillation at the output stage which shows up when the output pot is either between -infinite and 40 and when is between 6 and 0 (IE the two extreme parts of the run).
this happens regardless of the input attenuator pot, but it happens when there is no signal going through it. IE = no sinewave or music.

the scenario is the following:
if you turn the comp on and leave the input pot to zero and the output pot to zero there is a self oscillation (which shows up on the meter even when in gain reduction mode).
as soon as you rise the output pot the oscillation disappears and it comes back on the last 1/4 of the pot ride: between 6 and 0.

I have conducted some tests and apparently the oscillation appears in the signal line amp section and it goes away if I touch collector of Q4, the base of Q5 or the collector of Q6.

shorting the input doesn't do anything, nor the oscillation disappears if I touch any other component on any other part of the board.
I have tried to move the board around in the chassis but it not make any difference.
the oscillation (if seen on a scope) looks like (and sounds like) a quick burst of dc which goes form -100 to + 10 dBu every 250 mS (ish).

mmm puzzled.bad transistor? bad earth?

any hint will be much appreciated.

Bet,
Mattia.

what could cause that section to self oscillate?
Title: Re: 1176LN Rev D DIY
Post by: joe-electro on April 10, 2009, 05:32:03 PM
Look for solder jumpers across adjacent traces.

Joe


Hi everybody just finishing my first unit,
I did the full calibration procedure today (although I have tested it in the studio the other day without calibrating it...I was too curious!) and althought everything went fine I have a problem:

there is a self oscillation at the output stage which shows up when the output pot is either between -infinite and 40 and when is between 6 and 0 (IE the two extreme parts of the run).
this happens regardless of the input attenuator pot, but it happens when there is no signal going through it. IE = no sinewave or music.

the scenario is the following:
if you turn the comp on and leave the input pot to zero and the output pot to zero there is a self oscillation (which shows up on the meter even when in gain reduction mode).
as soon as you rise the output pot the oscillation disappears and it comes back on the last 1/4 of the pot ride: between 6 and 0.

I have conducted some tests and apparently the oscillation appears in the signal line amp section and it goes away if I touch collector of Q4, the base of Q5 or the collector of Q6.

shorting the input doesn't do anything, nor the oscillation disappears if I touch any other component on any other part of the board.
I have tried to move the board around in the chassis but it not make any difference.
the oscillation (if seen on a scope) looks like (and sounds like) a quick burst of dc which goes form -100 to + 10 dBu every 250 mS (ish).

mmm puzzled.bad transistor? bad earth?

any hint will be much appreciated.

Bet,
Mattia.

what could cause that section to self oscillate?
Title: Re: 1176LN Rev D DIY
Post by: rodabod on April 10, 2009, 06:00:30 PM
Mattia, I know you said it is occuring in the line amp section, but have you also 'scoped the preamp section for low level oscillation and also the power supply rails? Just thought I'd ask.

As always I'd double-check wiring and consult Skylar's wiring drawing too.

Cheers,

Roddy
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 10, 2009, 06:27:50 PM
Quote from: Joe
Look for solder jumpers across adjacent traces.

Joe

thank you will do so first thing tomorrow morning!

Quote from: Roddy
Mattia, I know you said it is occuring in the line amp section, but have you also 'scoped the preamp section for low level oscillation and also the power supply rails? Just thought I'd ask.

As always I'd double-check wiring and consult Skylar's wiring drawing too.

Cheers,

Roddy

I'll check the preamp section tomorrow and make sure it actually comes from the line amp.weird it seems like it just appeard now...
I'll also double check the wiring too, although I have done that already.


thank you guys for your suggestions!

Rock and Roll!

Best,
Mattia
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 11, 2009, 07:49:29 PM
Still regarding the output oscillation:

no solder jumpers across adjacent tracks the wiring looks ok too.

I cannot track the oscllation down because as soon as I put my scope probe on any part of the circuit the oscillation disappears.
(is it called capacitive reactance?)
 
I also have noticed that it does it with:
my headpphones preamp (custom build) and as insert return.it behaves normally when nothing is connected to it or when I plug my neutrik A1 at the output.

this is interesting.
I wonder if the output transformer might be loaded (or loading) or If I have connected it wrongly to the mother board.

-Can anyone confirm the MNats color coding on the pcb is correct when using hairball 5002 output trafo, please?

-also, when I first powered the unit up the resistor across the primary output trafo went up in smoke.
rewired the trafo, replaced resistor and replaced the 3053 transistor.
does anyone think I should also replace the other transistors in the line amp section?


mmm I am curious to see where the problem lies.

PS Happy Easter everybody!

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 11, 2009, 09:04:14 PM
-also, when I first powered the unit up the resistor across the primary output trafo went up in smoke.
rewired the trafo

That's the thing about using Skylar's wiring guide.  His is based off the V1 PCB...the output wiring is different for the V2.

Go to Mnats site and download the V2 pdf guide (on the left).  Check the PCB layout in the V2 PDF and make sure you have the colors right.  It's the same for the 5002.

Make sure you connect the remaining orange and yellow wires together (off the board), connect the blue to + (hot) and red to - (cold).

Mike

Edit: Oh I see in your earlier post you may have already done this.
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 12, 2009, 07:57:14 AM
Quote from: Mike
Make sure you connect the remaining orange and yellow wires together (off the board), connect the blue to + (hot) and red to - (cold).

Mike


is this a must? I have connected red as hot (+) and blue as cold (-)...would this be the problem?

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 13, 2009, 06:45:52 PM
AH!

I have built 3 units so far an believe or not they all behave the same.

Then today I tried to swap pin 2 and 3 at the output transformer (IE= pin 2 is Blue and pin 3 is red) and at the input (for phase consistency).
guess what?

oscillation is gone.
now questions:

-how many people in EUROPE have built this unit, I mean how many have used the "standard european configuration" pin 2 being hot and pin 3 being cold using hairball 5002 trafo? Am I the only one?

-why did it mis-behave like that?If I understand correctly there is a form of negative feedback going back into (or from) the transformer in the output stage, what could happend if the output polarity is reversed?Would that become POSITIVE feedback and therefore generate instability?


I will conduct more tests tomorrow just to make sure I haven't foreseen anything but the baby seemed stable.


Best,
Mattia.


 
Title: Re: 1176LN Rev D DIY
Post by: rodabod on April 13, 2009, 06:49:50 PM
If I understand correctly there is a form of negative feedback going back into (or from) the transformer in the output stage, what could happend if the output polarity is reversed?Would that become POSITIVE feedback and therefore generate instability?

Sounds like you have hit the nail on the head. Well done. I wouldn't have thought of that...
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 14, 2009, 03:59:55 PM
ehm silly question...
the absolute phase ot my 1176 is now reversed compared to the rest my kit (PIN2 hot).
is my assumption correct?

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: JoleFIN on April 14, 2009, 08:32:15 PM
Okay my Q is about rev F but think it's ok here..

The BOM says 27pf ceramic capacitor, but I can't find one from my local supply and neither at Farnell (where I'm ordering most of the stuff in a bunch). Is there any substitute for this or should I order a surface mounted capacitor as in
http://fi.farnell.com/vishay-bc-components/k270j15c0gf5tl2/capacitor-27pf-50v-c0g/dp/1612200 (http://fi.farnell.com/vishay-bc-components/k270j15c0gf5tl2/capacitor-27pf-50v-c0g/dp/1612200)

Or more notoriously, am I missing something?

EDIT: Also, the 5M lin/log pots seem to be quite rare and it would cost an extra 30e + delivery times for Farnell to order one from the States... Any ideas where to get one in Finland/Scandinavia/Europe or does anyone have a spare?

"N00b", I hear them say... :)

-Jole
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 15, 2009, 01:23:11 AM
sorry if i am getting off topic a little here, but i thought i'd post the wiring diagram i used to get my dual rev. d functional.  i used all the parts that are now conveniently located at Hairball audio. It proved very useful for me while i was wiring the thing up.  As Skylar graciously posted his diagram for the vers. 1 board, i thought i'd post mine (vers. 2 board) as it has the updated wiring info for the OT and rotary switch and meter boards. 

Also, in regards to the polarity of the OT wiring, my unit is wired with the blue on cold (-) and red on hot (+) and i'm not having any oscillation problems.  Matta_Haze, is your unit working at 100% now that you switched your wiring around?  it makes me wonder if i'm missing something.....   



Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 15, 2009, 04:17:32 AM
Quote from: carnitas
Also, in regards to the polarity of the OT wiring, my unit is wired with the blue on cold (-) and red on hot (+) and i'm not having any oscillation problems.  Matta_Haze, is your unit working at 100% now that you switched your wiring around?  it makes me wonder if i'm missing something.....   

well my unit was working fine even when the wiring was BLUE Cold (-) and RED Hot (+) but I noticed it did not like to be used on a unblanced insert (I have used a simple mackie 1604 to test) and it was giving me oscillations in that situation.
it would be interesting to see if yours (as it is connected now) does the same.
if not I got it wrong and therefore there is something else I did not see.

I have built 3 units so far and they all exibhit the same problem, unitl I swapped the output trafo connections..
VERY interesting...

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 15, 2009, 08:12:15 AM
hmmmm, that is interesting Mattia.  I'm sure i would not have ever come across that problem as, thus far, I have had no cause to use it as an unbalanced insert.  (i seriously didn't realize how much detective work was involved with this stuff.)

With your current wiring, do your units behave themselves when used as balanced links in the signal chain? Are there any audible differences?  Do the compression characteristics change? more, less aggressive? 

jj
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 15, 2009, 08:40:44 AM
Quote from: carnitas
(i seriously didn't realize how much detective work was involved with this stuff.)

in my case I had to use it on an insert (I do a lot of live gigs as well as studio work and therefore that's how I would use it) and that problem made it unusable.
I am not 100% convinced I nailed it down, as I haven't finished testing it, but I am quite confident.

On regards to wiring, yes it behaves as far as I could tell after a brief test.
Regarding differences in compression, no there is nothing I could hear as far as different behavior/sound, but again, Live sound (unless you have 3 hours for sound checking) is not the place where I could test a piece of kit.
it does work or it does not, move onto the next one.

I'll be working on it tonight again and I'll do some tests balanced/unbalanced in the workshop where I can have enough time to judge.
that should tell me if there is anything different between bal/unbal level and behaviour wise.

in the mean time it would be interesting if you could do the same test on yours to see if the problem arise.

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 15, 2009, 10:52:45 AM
yes, that does sound like an interesting experiment.  i probably won't get to it for a week or so as work deadlines are quickly approaching.  i'll keep you posted when i get a chance to flip the wiring around in one of the channels. 

jj
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 15, 2009, 12:14:15 PM
Quote from: carnitas
yes, that does sound like an interesting experiment.  i probably won't get to it for a week or so as work deadlines are quickly approaching.  i'll keep you posted when i get a chance to flip the wiring around in one of the channels.

thanks.

Best,
Mattia.
Title: Re: 1176LN Rev D DIY
Post by: crisotop on April 19, 2009, 01:44:29 PM
Hey folks,

I'm about to complete my partslist for a dual Rev D build and am wondering if it would be possible to build a stepped T-Attenuator? Page 29 (http://www.groupdiy.com/index.php?topic=20058.560) of this thread has a nice drawing for a 12 pos t-pad if I'm getting this right? I'm thinking of using a 2-deck 24 pos Elma for this purpose - I just want to make sure this can be done, should make level settings in stereo mode a lot easier.

thanks in advance,
christoph
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 19, 2009, 01:54:23 PM
Yes for sure it can be done.

There is a good thread somewhere, but basically it was about using the NYDave drawing from page 29.

You need a MBB switch.

Mike
Title: Re: 1176LN Rev D DIY
Post by: crisotop on April 19, 2009, 02:56:27 PM
Thanks Mike, I'm going to investigate a bit more, mainly I need to figure out the needed resistor values for 21 steps...

christoph
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 19, 2009, 03:34:30 PM
Check out this NYDave post:
http://www.groupdiy.com/index.php?topic=10593.msg254707#msg254707

Dave's made several great posts on the subject.

Mike
Title: Re: 1176LN Rev D DIY
Post by: pstcho on April 19, 2009, 04:19:01 PM
does this version (d) sounds as good as the G1176?

thank you
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 19, 2009, 06:41:01 PM
does this version (d) sounds as good as the G1176?

That's really up to you.

I think it sounds a lot better on most things.  But there are people who prefer the late F/G "silverface" models who may prefer the G1176.  It's like asking if blonds are prettier than brunettes (or redheads). 

The RevD and RevA are closer to their originals.  The attenuator, transformers and pretty much everything between is like the real original circuit.  The G1176 is a little different, it was designed when there was not really access to a lot of stuff that has become available in the past year.  If 600ohm T pads with the unique tapers used in the 1176, UTC O-12 clones and output transformers with tertiary feedback winding were readily available back when the G1176 was designed, it may very well have been based on the D.  However, since those parts were expensive or hard to find at the time, it was designed as a F/G type(ish) with standard available components.

The original 1176 never used OEP or Lundahl transformers like the ones used in the G1176...but that isn't necessarily a bad thing.

It's all about personal taste.

Sorry for the non answer ;)

Mike
Title: Re: 1176LN Rev D DIY
Post by: pstcho on April 20, 2009, 03:09:42 AM
no it's exactly what i would like to have

thank you very mutch
Title: Re: 1176LN Rev D DIY
Post by: crisotop on April 20, 2009, 03:20:27 AM
Quote
Check out this NYDave post:
http://www.groupdiy.com/index.php?topic=10593.msg254707#msg254707

Dave's made several great posts on the subject.

Mike

Mike, this was most helpful - I'll post back here, once I've done my homework...

thanks a lot!
christoph
Title: Re: 1176LN Rev D DIY
Post by: gary o on April 20, 2009, 07:15:34 AM
I have a Transistor question........Im in Uk having trouble finding 2n3391 & 2n3707 for my Rev D ....I can get one or the other if I pay extra delivery costs its working out very expensive

Ive done some searches but have ended up more confused ......

Questions is what could I use instead of  2N3391 & 2N3707 ?...... & is it that simple ?

I read in my searches BC107 instead of 2n3391 ?

I read Q7 to Q10 2n5088 as in Purple machine.....instead of 2n3707.....but would that mean other 2n3707 could be replaced with 2n5088 within the circuit ?

Im having similar problems with a Rev A Im currently building too....

I try not to ask these qestions dont like to clog up these long threads I do searches but its difficult and threads long answers sometimes hard to find correct answers....I wonder if there are alternative transistors if we could list them in the BOM

Thanks ....
Title: Re: 1176LN Rev D DIY
Post by: RedNoise on April 20, 2009, 07:43:36 AM
Hi Gary , I found 2N3707 @ Evilbay...
Hope this help!
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 20, 2009, 07:51:53 AM
gary, i think a lot of folks were having trouble getting the proper HFE from the 2n3707 transitors.  I've substituted 2n3708 for all of mine and have had no problems.  there's a lot of talk about it pretty early in this thread.  FYI
Title: Re: 1176LN Rev D DIY
Post by: Skylar on April 20, 2009, 10:00:39 AM
gary, i think a lot of folks were having trouble getting the proper HFE from the 2n3707 transitors.  I've substituted 2n3708 for all of mine and have had no problems.  there's a lot of talk about it pretty early in this thread.  FYI

Yes, what he said!
Title: Re: 1176LN Rev D DIY
Post by: gary o on April 20, 2009, 03:02:01 PM
Thanks for replys
Found 2n3055 nice n cheap 3p each at Farnell
Found Ebay seller thanks rednoise... ebay have 2n3391 quite expensive if are not gonna work & have 2n3708 cheap & you guys say will work ?
Re earlyer discussion in thread ...il have to read thru the lot then thanks...I do think it would be good to add some info to the BOM Im sure others will come along asking same questions as me...

Thanks for all help il post what i buy & where from & how if it all works as to help others
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 20, 2009, 03:27:57 PM
yes, 2n3708 will work fine.  the issue was that folks were having a hard time finding 2n3707s with an HFE over 250.  all my 2n3708s averaged between 350 and 450. 

as far as an updated BOM, i don't know about that, but the first post has a link to Kato's parts list for folks who live in the states.  That's the parts list i used and all of it has checked out fine.....with the exception of the 6 position rotary switch (no ability to implement the "all button mode" as far as i can tell).  But i'm replacing those switches with the alpha switches on Mnats rotary switch wiring page.   

Its all here in these pages.  Even when i could swear that it wasn't here, i'd find it a few minutes (or hours, or days) later.  This thread addresses most of the issues i've encountered with my build and has given the info to troubleshoot.  In many cases, information i initially glanced over became very valuable later. i.e.  wire the output transformers correctly or witness the untimely demise of R32.   

it will take some time but its worth it.  before this build, i couldn't tell AC from my a$$hole.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 20, 2009, 03:30:45 PM
I'm going to start selling transistors at my store.

I'll have match pairs of 2n5457's starting this Wednesday.

In the next 2 weeks I'll be selling 2N3708's and 2n5088's with high enough HFE's and within 5% of each other.

Hopefully that will provide another option.

Mike
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 20, 2009, 04:14:28 PM
cool, mike.
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 20, 2009, 10:32:53 PM
mattia, i rewired the output of one of my channels (from the EA 5002) and in an extremely cursory test found it made no impact on the sonics of the comp.  there was slightly more noise when the blue wire was connected to the hot pin and the red to the cold, but that could easily have just been a bum joint somewhere or that some wires need to be moved or something.  This test was only done with vocals, so i'll check it out on some other souces with different frequency curves to see if there are any losses on either side of the spectrum.  in any case, i don't have any oscillation in either of the channels. 

interesting experiment.  Mike i noticed that you were the one who was pretty explicit about the wiring of the OT a page or so ago, any comment on this? 

regards, jj
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 21, 2009, 12:10:17 AM
Looking at the schematic:

Blue goes to output labeled as "X" or "+/-" on the back plate
Red goes to output labeled as "Y" or "Common" on the back plate

I always assumed since "common" is usually negative that would be the cold.

I could be wrong though.  Wouldn't switching red/blue flip the phase?

Mike
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 21, 2009, 01:03:33 AM
Quote
Blue goes to output labeled as "X" or "+/-" on the back plate
Red goes to output labeled as "Y" or "Common" on the back plate
I always assumed since "common" is usually negative that would be the cold.
I could be wrong though.  Wouldn't switching red/blue flip the phase?

well, that's what i wondered as well.  and it may have.  but i have yet to hear it affect anything in the real world.  If the polarity were reversed i suppose i would expect a notable difference in the frequency curve. I personally haven't experienced this (again, just with a 4 minute, very unscientific test).  But it sounds like i would have drawn the same conclusion from the schematic were i to have seen it. sort of puzzling.

by the by Mike, would you happen to have a copy of the scheme that you could share or is it already buried in this thread somewhere and i missed it. 

Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on April 21, 2009, 01:14:06 AM
Nice collection here:
http://www.waltzingbear.com/Schematics/Urei.html

Mike
Title: Re: 1176LN Rev D DIY
Post by: carnitas on April 21, 2009, 01:28:45 AM
aha!  i see it now.  i didn't follow the traces back through the schematic when i looked at it last and so just (semi-arbitrarily) assigned values to "X" and "Y" by the usual color coding (red=hot, blue=cold).   still though...its strange that it hasn't appeared to make much difference.  does anybody else have this experience? 

i don't mind being exposed for the novice that i actually am.

jj
Title: Re: 1176LN Rev D DIY
Post by: mata_haze on April 21, 2009, 02:06:11 PM
Quote from: JJ
does anybody else have this experience?

no...I haven't noticed any difference...

Mattia.
Title: Re: 1176LN Rev D DIY
Post by: crisotop on April 26, 2009, 08:04:33 AM
Regarding stepped T-Attenuators again:

(http://electronicdave.myhosting.net/miscimages/600bridgedt.gif)

I just cross checked NYDave's drawing with the calculator at http://www.microwaves101.com/encyclopedia/calcattenuator.cfm (http://www.microwaves101.com/encyclopedia/calcattenuator.cfm) and the values don't quite match? Can anyone explain which formula is correct, or what the difference between the two is?

Some quick example values for z0 = 600R
2dB Atten: R1=155.36   R2=2,317.27
4dB Atten: R1=350.94   R2=1,025.83

Thanks
Christoph

Title: Re: 1176LN Rev D DIY
Post by: keefaz on April 26, 2009, 08:13:52 AM
For the R2 equivalent in NYD circuit, you have to add all resistor values from the db atten pin to gnd
(resistors are in serie)
Title: Re: 1176LN Rev D DIY
Post by: crisotop on April 26, 2009, 08:19:02 AM
Damn, how stupid am I  :D - thanks keefaz!

christoph
Title: Re: 1176LN Rev D DIY
Post by: luis on May 01, 2009, 10:54:32 PM
I´m using a pushbutton Purusha case,  but the Sifam bezel does not fit on the extra pannel (the one used to hold the buttons).
The Sifam i´m using is the AL29WF wich fits perfect in the front pannel, but not in the extra one.

Did any of you had this problem. If not, Maybe my case is defectiv!

Thank you
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on May 03, 2009, 01:09:07 AM
It SHOULD fit... Put the bezel on the meter first and wiggle it in as an assembly. May a bit of a snug fit. Just use some care.

John
Title: Re: 1176LN Rev D DIY
Post by: ewald on May 03, 2009, 04:59:19 AM
There is a step by step guide for this about 2/3 down Mako's J page:
http://www.geocities.com/m_natsume/1176-wiring-pushbutton.html

The only difference is to remember when he says "solder 22/Grn/Blk to the meter board" it will be the attack pot switch for you.

Mike

HI guys,

Firstly I want to thank all the contributers to this tread/project, I sallute your selfless divulgence of time and knowledge...wich i directly attribute the success of my now fully functioning revD to!

One thing still stumping me though. I used the spdt switch for the attack controll and wired it according to the hairball instructions. I.e common to 22(main) ; CCW(off) to BLK and CW to GRN on ratio board. Now, BLK on the ratio board connects to ground, wich allows GR to be disabled on the attack switch CCW(off) position, BUT on the ratio pcb board (also indicated on ratio board schematic)  the 4:1 switch connects the 4:1 ratio circuit to the BLK pad, automatically shorting the 4:1 ratio circuit to ground when selected. This was confirmed in the compressor's behavior i.e the 4:1 ratio selector acting as GR disable switch. I remedied this by removing the ground connection from BLK on the ratio board-obviously also removing GR disable functionality from CCW on attack pot.

Can anyone confirm this OR that i'm missing something?

Title: Re: 1176LN Rev D DIY
Post by: luis on May 03, 2009, 08:46:01 AM
It SHOULD fit... Put the bezel on the meter first and wiggle it in as an assembly. May a bit of a snug fit. Just use some care.

John

Thank you, but it won´t work. I will have to cut a little of the inside pannel.
Just tought that you guys may had the same problem :)

Title: Re: 1176LN Rev D DIY
Post by: pantsonfire on May 07, 2009, 09:21:04 PM
Howdy,

Does anyone have Mouser or Digikey part numbers handy for a 3 pin header and shorting plug like Mnats suggests using for removing R44 from the circuit during the Discrete Meter Circuit Calibration? They're not listed in his BOM or Kato's (though mostly everything else is, so I'm not complaining).

Many thanks,
Chris.
Title: Re: 1176LN Rev D DIY
Post by: Skylar on May 07, 2009, 10:04:50 PM
Mouser or Digi-Key PNs


3-pin header 0.100" spacing
22-28-4030


shorting jumpers
STC02SYAN

Title: Re: 1176LN Rev D DIY
Post by: pantsonfire on May 07, 2009, 10:35:40 PM
Thanks so much Skylar! It was the spacing that I was unsure about. Thanks also for all of your other helpful input in this thread.

Best,
Chris.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on May 08, 2009, 02:01:20 AM
One thing still stumping me though. I used the spdt switch for the attack controll and wired it according to the hairball instructions. I.e common to 22(main) ; CCW(off) to BLK and CW to GRN on ratio board. Now, BLK on the ratio board connects to ground, wich allows GR to be disabled on the attack switch CCW(off) position, BUT on the ratio pcb board (also indicated on ratio board schematic)  the 4:1 switch connects the 4:1 ratio circuit to the BLK pad, automatically shorting the 4:1 ratio circuit to ground when selected. This was confirmed in the compressor's behavior i.e the 4:1 ratio selector acting as GR disable switch. I remedied this by removing the ground connection from BLK on the ratio board-obviously also removing GR disable functionality from CCW on attack pot.

Can anyone confirm this OR that i'm missing something?

Something is not right here, unfortunately I'm too tired to think straight.  BLK should conect to the 47K resistor on the ratio board.

Have a look at it again and walk through the Mnats wiring guide again.  Let me know if you still have the issue and I'll crack mine open and see what's going on.

Mike
Title: Re: 1176LN Rev D DIY
Post by: rrs on May 09, 2009, 09:44:46 AM
Hi guys I'm just starting this project.

One question - I have the Rev 2 board and have installed 1N4004 instead of 1N4003 (CR7,8,9,10) as I was reading version 1 instead when ordering. I have soldered these in before realizing.
Will I need to change these or would either be ok?
Title: Re: 1176LN Rev D DIY
Post by: jdbakker on May 09, 2009, 10:26:19 AM
I have the Rev 2 board and have installed 1N4004 instead of 1N4003 (CR7,8,9,10) as I was reading version 1 instead when ordering. I have soldered these in before realizing.
Will I need to change these or would either be ok?

http://www.groupdiy.com/index.php?topic=31224.0

JDB.
Title: Re: 1176LN Rev D DIY
Post by: ewald on May 09, 2009, 11:20:47 AM
rrs, you're fine, the only difference between the IN4003/3's is power rating, i.e IN4004 can take more current.

Mike, thanks for your reply, I'm gonna recheck the whole thing and report back.(I'm counting on user error!!) I have been using it in studio this week and it rocked hard, :) only thing being that 4:1 not showing any GR on meter or by ear (with 22[shield to grnd] connected to ground) and even with ground removed I have to really push it to get a couple of db's GR.

ciao
Title: Re: 1176LN Rev D DIY
Post by: jdbakker on May 09, 2009, 12:52:21 PM
the only difference between the IN4003/3's is power rating, i.e IN4004 can take more current.

That's incorrect. Power and current rating's exactly the same for all diodes in the 1N4001-1N4007 series.

JDB.
[one person's nit is another's major difference]
Title: Re: 1176LN Rev D DIY
Post by: ewald on May 10, 2009, 06:28:17 AM
I stand 'correctified' sir! :-[ The difference in fact lies in the peak inverse/reverse voltage rating.I.e higher designations in the series can handle higher voltages.JDB-excuse my ignorance: rrs-you're still good to go.

regards

Ewald
Title: Re: 1176LN Rev D DIY
Post by: luis on May 10, 2009, 02:05:38 PM
Hi,

I finish wiring my clone, and powered on for the first time. No smoke, and burned resistors/capacitors, but several probelms:

- Big Hum, and if put the output pot at Max value it starts to making some intermitent noise,
- The input pot (attenuator) doesn´t work, or at least I´ve noticed no difference when turning this pot.
- I connect an Audio source to input XLR and I could only barely hear it.
-

I´ve already disconnected everything to look at board carefully, to check for shorts, but i seems like don´t have any short on the board. I´ve populated it very carefully, and checked all resistor and capacitor values.

Help!

Considering the usuall procedures for problem checking, what would you suggest-me to do?


Thank you all,
Luis
Title: Re: 1176LN Rev D DIY
Post by: luis on May 12, 2009, 06:56:11 AM
Is there any chart for this rev d, to check dc voltages as there is with other rev´s?

Thank you
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on May 12, 2009, 11:41:39 AM
Double check all of your wiring.

Were you able to complete the calibration procedure?

Mike
Title: Re: 1176LN Rev D DIY
Post by: luis on May 12, 2009, 11:54:09 AM
I will try today, but with the problems i have I thin there no calibration salvation for me! >:(

Thanks  Mike



Hi,

I finish wiring my clone, and powered on for the first time. No smoke, and burned resistors/capacitors, but several probelms:

- Big Hum, and if put the output pot at Max value it starts to making some intermitent noise,
- The input pot (attenuator) doesn´t work, or at least I´ve noticed no difference when turning this pot.
- I connect an Audio source to input XLR and I could only barely hear it.
-

I´ve already disconnected everything to look at board carefully, to check for shorts, but i seems like don´t have any short on the board. I´ve populated it very carefully, and checked all resistor and capacitor values.

Help!

Considering the usuall procedures for problem checking, what would you suggest-me to do?


Thank you all,
Luis
Title: Re: 1176LN Rev D DIY
Post by: penguin on May 12, 2009, 06:41:16 PM
How to i make dual/stereo link on 1176...
i did search for 3-4 hours... most links are broken,
and some left on old forum.
help will be appreciated

i am using rev J


Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on May 15, 2009, 01:43:28 PM
the schematic is here: http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176SA.pdf

Is very simple. And the 1176 schematic showing where it goes is here: http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf
Title: Re: 1176LN Rev D DIY
Post by: penguin on May 15, 2009, 04:08:48 PM
i have founded this :
 
Two 1176LNs can be stereo coupled by using the 1176SA or Stereo Interconnect Accessory. The stereo-coupled setup needs to be calibrated, and the attack and release controls on each unit interact; changing the controls on either unit will affect both units. In stereo coupling mode, the attack time is doubled, so the fastest attack time in stereo is 40 microseconds.
full article about 1176s is http://www.barryrudolph.com/mix/ua1176.html

what is this "Stereo Interconnect Accessory" ???
1176SA is the Stereo Interconnect Accessor it self isnt it? or means just bare phone cable....???

yes, whole thing is very simple:
but, there is this roomer that 1176SA's circuit values have had been changed... and it doesnt work properly...
ie: purple audio version never worked properly ( quote from prodigy forums)

so, my question is changed to:
where can i find this 1176SA circuit's  correct values :)

thank you for the links btw...

EDIT :
mnats comment on 1176SA

http://www.groupdiy.com/index.php?topic=646.msg8731#msg8731

EDIT 2 :

1176SA only needed if your FETs are not matched!
if you have matched FETs you dont need 1176SA! just direct phone connection?

am i close?



Title: Re: 1176LN Rev D DIY
Post by: dissonantstring on May 15, 2009, 04:42:24 PM
penguin,
if you are posting about stereo linking on your Rev.J (G1176), then why are you posting in the 1176 Rev.D thread? ::)

i linked my two G1176 Rev.H boards with the info i simply did a search for in the G1176 build thread.  you don't need an SA unit for the G1176 (just a wire) and no matter what you do you will not get perfect tracking of both channels (no one on this forum has to my knowledge). 

rather than stereo, just call it dual mono (like mnats usually does). ;)
Title: Re: 1176LN Rev D DIY
Post by: penguin on May 15, 2009, 04:54:03 PM
J and D are same for stereo linking (pin 7, on both = .22uf / 3.9Mohm connection)

sorry if i was asking too much... i am pretty new here...

Title: Re: 1176LN Rev D DIY
Post by: dissonantstring on May 15, 2009, 05:06:19 PM
hi penguin,
sorry if i came off wrong, but if Rev.D and J are the same at linking...it's still just one wire (stereo link pad to stereo link pad - add a switch or connectors to your liking).   
regards,
grant
Title: Re: 1176LN Rev D DIY
Post by: penguin on May 15, 2009, 05:27:27 PM
its all cool, :) not to worry. 

regards 
penguin :)
Title: Re: 1176LN Rev D DIY
Post by: fazeka on May 17, 2009, 06:48:56 AM
Hi all,

Finally had some time to put together my 1176 Rev D this weekend, using Purusha's case with the inner front panel. Have a problem, however.

Seems my Alpha pots' bushings are not long enough (with the inner panel and the faceplate) to get the nut on.

How is everyone else using Purusha's case with Alphas getting around this malady?

Thanks,
Chris
Title: Re: 1176LN Rev D DIY
Post by: luis on May 17, 2009, 08:00:45 AM
I´ve had the same problem but i actually fit by putting some more pressure in the Pot against the hole. But sanding the extra pannel in the purusha case may be the sollution.
Title: Re: 1176LN Rev D DIY
Post by: pantsonfire on May 17, 2009, 05:26:05 PM
Well, I've used the search function and looked over the pages since Ver2 was introduced and read Mnats RevD page a few times and I still have to ask what seems like a redundant question...

What is the correct value for the Tracking Adjust trimmer R44?

I know it must be around here somewhere, but I've missed it apparently. Mnats' BOM lists a 1k and the board reads 2k. Mnats schematic lists it as "ADJ" and the Urei schematic has an asterisk, but no value that I can make out. The Ver1 BOM list a 1k resistor, but has a 2k trimmer in the layout file. Maybe it doesn't matter which, but I don't know that for sure so would someone please try to enlighten me? I don't want to solder in a 1k trimmer (which is what I have) and have to remove it because it won't adjust into the range I need. All the photos I've checked out have the values facing away from the camera.

Many thanks in advance,
Chris.   
Title: Re: 1176LN Rev D DIY
Post by: luis on May 17, 2009, 05:30:16 PM
You need at least 1K, 2K will work without any problem.




Well, I've used the search function and looked over the pages since Ver2 was introduced and read Mnats RevD page a few times and I still have to ask what seems like a redundant question...

What is the correct value for the Tracking Adjust trimmer R44?

I know it must be around here somewhere, but I've missed it apparently. Mnats' BOM lists a 1k and the board reads 2k. Mnats schematic lists it as "ADJ" and the Urei schematic has an asterisk, but no value that I can make out. The Ver1 BOM list a 1k resistor, but has a 2k trimmer in the layout file. Maybe it doesn't matter which, but I don't know that for sure so would someone please try to enlighten me? I don't want to solder in a 1k trimmer (which is what I have) and have to remove it because it won't adjust into the range I need. All the photos I've checked out have the values facing away from the camera.

Many thanks in advance,
Chris.   
Title: Re: 1176LN Rev D DIY
Post by: crisotop on May 18, 2009, 03:40:11 AM
I haven't had a look for the correct value, but waht about a 500R in series with your 1k pot?

regards,
christoph
Title: Re: 1176LN Rev D DIY
Post by: fazeka on May 18, 2009, 06:41:38 AM
I´ve had the same problem but i actually fit by putting some more pressure in the Pot against the hole. But sanding the extra pannel in the purusha case may be the sollution.

No good. I put more pressure and still not enough threads on the bushing to get the nuts started.

So I just opened up the panel to allow the pots to sit right up against the faceplate.

(http://img198.imageshack.us/img198/7747/attrel.jpg)

(http://img269.imageshack.us/img269/6761/out1.jpg)

(http://img269.imageshack.us/img269/8162/out2.jpg)

Should do the trick.
Title: Re: 1176LN Rev D DIY
Post by: carnitas on May 23, 2009, 01:17:28 PM
hey all, i've been having some grounding issues with my dual rev. D
I'm a little confused as i think i've read some conflicting information about appropriate grounding schemes and i may have synthesized some different ideas.  i'll start with the symptoms:

-low level hum in both channels when fully connected and powered up. 
-gain reduction is functional and sounds great. 


Grounding to chassis (star ground):
-IEC connector
-outputs on both channels (through the relay boards)
-ground input on both boards (terminal between positive and negative voltage terminals)

relavent information:
-PSU for boards (next to power transformer) is connected to the boards ground terminal, which in turn is grounded to the chassis
-PSU for relays and LEDs is not grounded to chassis (i tried to connect it to chassis ground and noticed no change)
-inputs were connected to the chassis as well, but then i disconnected them.  No change.
-I DON'T have pad 22 going to the chassis, which i've read is one appropriate way to ground the boards. 
-power transformer is an Avel Lindberg 30VA 25 + 25
questions:
-are the PSUs too far apart?
-should the PSU and power transformer be sheilded in an enclosure? (either within the case or externally)?


i appreciate any help anyone could give.  generally, i'm very happy with my first DIY project and this has been sort of fun to trouble-shoot.
http://s721.photobucket.com/albums/ww219/carnitas/?action=view&current=1176grounding2.jpg (http://s721.photobucket.com/albums/ww219/carnitas/?action=view&current=1176grounding2.jpg)
http://s721.photobucket.com/albums/ww219/carnitas/?action=view&current=1176004.jpg (http://s721.photobucket.com/albums/ww219/carnitas/?action=view&current=1176004.jpg)
thanks to anybody who is willing to give a look.
jj
Title: Re: 1176LN Rev D DIY
Post by: rrs on May 25, 2009, 01:24:57 AM
RE: Wiring diagram below.

There are some extra links I would like to know about. D8 to R87 and D11 to CR6 .



sorry if i am getting off topic a little here, but i thought i'd post the wiring diagram i used to get my dual rev. d functional.  i used all the parts that are now conveniently located at Hairball audio. It proved very useful for me while i was wiring the thing up.  As Skylar graciously posted his diagram for the vers. 1 board, i thought i'd post mine (vers. 2 board) as it has the updated wiring info for the OT and rotary switch and meter boards.  I lifted Skylar's grounding scheme for the layout (my unit is terrifically quiet!). 

Also, in regards to the polarity of the OT wiring, my unit is wired with the blue on cold (-) and red on hot (+) and i'm not having any oscillation problems.  Matta_Haze, is your unit working at 100% now that you switched your wiring around?  it makes me wonder if i'm missing something.....   


BTW, this was my first build.  Took a while.  lots of screw ups.  lots of reading.  totally worth it. 
Title: Re: 1176LN Rev D DIY
Post by: carnitas on May 25, 2009, 02:21:37 AM
rrs, those links are used because i did not use the on-board power supply.  I powered two boards from one of mnats little psu supplies and so jumped the PSU circuit for the boards.   

The jumpers need to go from CR7 to R87 and from CR10 to CR6
i updated the pdf that i'd posted a while back and fixed it to include those designations.  Also realized that the meter wiring was backwards in the diagram which i fixed as well as  the PSU jumper from CR7 to R87 (previously it was going to the wrong side of R87.) 

if you've been following the diagram to wire your board(s) up, be wary the grounding scheme.  i've got some hum in there (mentioned above) and am still trying to figure that out. 


Title: Re: 1176LN Rev D DIY
Post by: pantsonfire on May 30, 2009, 01:35:38 PM
You need at least 1K, 2K will work without any problem.

Sorry for the slow re-reply.
Thanks very much for the info.

Best,
Chris
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 07, 2009, 08:16:01 PM
Is this ground mod worth adding to the 1176 Rev D. It's used on the Drip La2a Version 3 Board. Would I need to change any of the configuration for it to work like change the resistors and the caps? Anyone use some type of grounding like this before on their 1176 Rev D and did it work or is it not worth putting in?

(http://www.freeimagehosting.net/uploads/4c91c65169.jpg)
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 09, 2009, 07:19:53 AM
I´ve had the same problem but i actually fit by putting some more pressure in the Pot against the hole. But sanding the extra pannel in the purusha case may be the sollution.

No good. I put more pressure and still not enough threads on the bushing to get the nuts started.

So I just opened up the panel to allow the pots to sit right up against the faceplate.

(http://img198.imageshack.us/img198/7747/attrel.jpg)

(http://img269.imageshack.us/img269/6761/out1.jpg)

(http://img269.imageshack.us/img269/8162/out2.jpg)

Should do the trick.
What tools did you use to cut those out perfectly.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 09, 2009, 09:42:56 AM
J and D are same for stereo linking (pin 7, on both = .22uf / 3.9Mohm connection)

sorry if i was asking too much... i am pretty new here...


Are you saying that pin 7 is the tip(hot) of the connector in a TS socket for stereo link? Is pin 7 send or return? Where is send and return for the stereo link though? Where do you get the shield or S part of the socket, do you just grab the ground from the case?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 09, 2009, 09:47:35 AM
Where is the latest, I am talking the super latest, current, tried and tested wiring diagram for the Mnats 1176 Rev D board with Push Buttons? I have 3 versions and I am concerned that I do not have the latest, non faulty, no updates needed wiring diagram.

Is it this one here SG-1176-RevD-Wiring_ALLv3.pdf the latest????

http://www.filefactory.com/file/ag514d3/n/SG-1176-RevD-Wiring_ALLv3_pdf  (http://www.filefactory.com/file/ag514d3/n/SG-1176-RevD-Wiring_ALLv3_pdf)



Title: Re: 1176LN Rev D DIY
Post by: ewald on June 09, 2009, 11:26:43 AM
Hi canidoit,

Mako's (mnats) wiring guide on his web page (and the schem for refference) is all you need. 

This was my 1st  diy aswell and she fired up 1st time.
Take the time to learn about the circuit and build in general before you start. A crucial read is the original urei manual.(and read all 40 odd pages of this thread to warm ya self up!) 

Make a point of not painting her by numbers & you'll be sure to learn heck of allot and avoid  troubleshooting someting you know nothing of!(troubleshooting will most likely be mandatory:-))

Cheers

Ewald
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 09, 2009, 01:27:29 PM
Well said Ewald.

The original schematic is the most tried and tested wiring guide.  Other then a few obvious changes for the D, Mako's site goes through the wiring step by step.

http://www.waltzingbear.com/Schematics/Urei.html

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 10, 2009, 05:50:25 PM
Can this 1176 build do "All Button Mode"? I am using the Hairball pushbutton parts and board.

Hairball, I was going thru your Push Button board manual and the parts list on your manual do not match the BOM North American link you gave me. Like for example, you have a resistor there that's 1/2 watt which on the BOM is 1/4 watt. You also have more resistors. Should I follow your manual that came with your boards for the push buttons?

Also the addition of the connector for the push button boards are great : ), very pro. You should supply them with your boards. Those connectos are not in the BOM which I purchased seperately.
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on June 11, 2009, 02:17:01 AM
I didn't use any connectors on all 3 of mine. I soldered the wires straight to the boards. And nuke works fine with the buttons just like the original.

John
Title: Re: 1176LN Rev D DIY
Post by: tman on June 12, 2009, 01:18:10 PM
Hey all;

Got my rev d up and running. I've got one issue that I can't seem to find an answer to.
Upon trying to do the Q-bias calibration, if i turn R59 CW, the meter only rises, and I cannot get a 1db drop. I've scoured all sources online, but I can't find any mention of this. If anyone can point my in some direction I'd greatly appreciate it.

Tony
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 12, 2009, 05:41:05 PM
Hey all;

Got my rev d up and running. I've got one issue that I can't seem to find an answer to.
Upon trying to do the Q-bias calibration, if i turn R59 CW, the meter only rises, and I cannot get a 1db drop. I've scoured all sources online, but I can't find any mention of this. If anyone can point my in some direction I'd greatly appreciate it.

Tony
Hint: if you turn it in the other direction, does it drop?
Title: Re: 1176LN Rev D DIY
Post by: tman on June 13, 2009, 11:29:56 AM
Mnats;

Yes it does!!
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 13, 2009, 11:55:33 PM
I did a search and only saw one person mention this and no one answered...

R12 calls for a 920ohm, right? It was previously I guess a 1.8K. Anybody have a source for one of those? Neither Mouser nor Digikey seems to have these in stock, though I could just not be searching correctly. Would a 1K really affect things particularly much if a 920 wasn't readily available?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 14, 2009, 01:26:59 AM
I did a search and only saw one person mention this and no one answered...

R12 calls for a 920ohm, right? It was previously I guess a 1.8K. Anybody have a source for one of those? Neither Mouser nor Digikey seems to have these in stock, though I could just not be searching correctly. Would a 1K really affect things particularly much if a 920 wasn't readily available?

I had the same problem. I think you have like a tollerance range where you can be off by so and so. I was able to get 910ohm. Heres the link.

271-910-RC – Xicon $0.13 US 500v 0.25w 1%
http://au.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtMTfExsNintaoUUGC3c4SIqA42TN1Yq7M= (http://au.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtMTfExsNintaoUUGC3c4SIqA42TN1Yq7M=)

I can send you my Exell spreadsheet if you want. I organised it pretty well with active links and made boxes so you can mark it when you print it out or mark it on Exell as you go along, buy the parts and solder, etc. Also made some references, notes and color coded what parts are used on the audio path so you can change the part if you like to alter the sound and also what supplier it is sourced from.

Always re-confirm my data though to make sure I have done it correctly.

Also take note on the Attack Pot in the BOM list. You need to get one with the SPDT switch built if you are using Purusha's case or cases that look like the original 1176 where the attack pot has the ability to turn off the attack. It looks silly if you don't have that feature in and its on your 1176 front markings.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 14, 2009, 02:36:29 AM
Quote
I had the same problem. I think you have like a tollerance range where you can be off by so and so. I was able to get 910ohm. Heres the link.

271-910-RC – Xicon $0.13 US 500v 0.25w 1%

Thanks. I e-mailed them to add 2 of those to the order I just made, one plus a backup.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 15, 2009, 05:30:00 AM
Anyone have any 2n3708 higher than 250 hfe that are excess to their builds, message me?
Title: Re: 1176LN Rev D DIY
Post by: crisotop on June 15, 2009, 05:35:20 AM
If you can wait a couple of days, I'm currently selecting some...

cheers
christoph
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 15, 2009, 05:52:52 AM
If you can wait a couple of days, I'm currently selecting some...

cheers
christoph
There is still hope  :)

It be better though if you were from Australia, saves on shipping costs.
Title: Re: 1176LN Rev D DIY
Post by: crisotop on June 15, 2009, 06:34:03 AM
Austria/Australia, that's nearly the same (the old kangaroo/alps stereotype comes to mind...)


Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 15, 2009, 11:58:16 AM
So, it was too late to get the two 910 ohm resistors onto my last order. I don't want to pay another $7 bucks to ship 50 cents worth of resistors. Could I just use a 300 and 600 ohm in series and be close enough?
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 15, 2009, 12:09:14 PM
Could I just use a 300 and 600 ohm in series and be close enough?

Definitely.

Or two 1.8K in parallel.

Title: Re: 1176LN Rev D DIY
Post by: tman on June 15, 2009, 12:23:38 PM
The rev D rules!!

Thanks to Mnats, Mike at Hairball for the parts, and all who posted, for the info.

Will post pics soon.


Tony
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 15, 2009, 06:51:37 PM
Oh, man, I screwed up on cutting my meter hole. I got confused about the orientation and it ended up too low. It's flush with the bottom of the front panel, but the bottom and top panels have a lip that come over, so it'll never it. Planning is everything, and I planned this one much more than the LA-2A. But when I sat everything out on the front panel to find the locations, I only put the bezel of the meter on there, so I failed to remember the extension of the meter on the bottom internally.

Soooo... I had no choice but to rotate all of the pots 180 degrees (I'm doing a rotary), flip the meter over, and flip the front panel the other way. So I will soon be the owner of a very rare left handed 1176 :o I hear that Jimi Hendrix used it at one time.

Oh well, makes no difference to me. The front panels of my LA-2A and 1176 aren't going to be labeled anyway, since I don't have any good way to do it, so it makes no difference what order the knobs are in one way or another. I'll just flip the mounting positions of all the internals the other way as well to retain optimal locations for wiring.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 15, 2009, 08:39:31 PM
So, just a couple questions... They seem obvious but just to make sure I'm not missing something:

1. I'm using the Hairball kit. I assume that I don't need Mnat's input xformer board in that case, right? I just use the one that came with the input xformer in the Hairball kit? It's very much simpler and has fewer connectors than the Mnats one, but I assume that's because his supports various xformers and therefore some need more connections, eh?

2. I noticed in Skylar's wiring guide that there were some resistors and caps wired into the attack pot I think it was, but I don't see those in the Rev D rotary wiring guide. Is that some optional or just something from a previous rev of these boards that is now not requird?

3. I'm doing a rotary version. So I should just leave out R77 altogether on the main board, or should it be jumpered or something? I already put it in before I noticed that in the schematic it says not used in the rotary version, so I guess I'll to clip that one out, eh?
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 15, 2009, 09:20:49 PM
So, just a couple questions... They seem obvious but just to make sure I'm not missing something:

1. I'm using the Hairball kit. I assume that I don't need Mnat's input xformer board in that case, right? I just use the one that came with the input xformer in the Hairball kit? It's very much simpler and has fewer connectors than the Mnats one, but I assume that's because his supports various xformers and therefore some need more connections, eh?

Yes the one you received from mnats is the original board that can be used for various input transformers including the one I sell.  If you are using the transformer I sell then just use the board I sent you.  It's designed by mnats specifically for this transformer, no jumpers needed.

2. I noticed in Skylar's wiring guide that there were some resistors and caps wired into the attack pot I think it was, but I don't see those in the Rev D rotary wiring guide. Is that some optional or just something from a previous rev of these boards that is now not requird?

I must confess I know very little about wiring the rotary version.  I believe those components on the pots are on the ratio PCB for the rotary version.

3. I'm doing a rotary version. So I should just leave out R77 altogether on the main board, or should it be jumpered or something? I already put it in before I noticed that in the schematic it says not used in the rotary version, so I guess I'll to clip that one out, eh?

I believe R77 is the 8.2k resistor used for +8 metering and should not be on the main board at all.  Are you getting it confused with R76 (also 8.2K)?  R77 is on the meter PCB for the pushbutton version.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 15, 2009, 09:26:32 PM
Quote
I must confess I know very little about wiring the rotary version.  I believe those components on the pots are on the ratio PCB for the rotary version.

Oh yeh, I didn't make that connection. Sorry. I guess I saw somewhere back in the misty past of this thread where he at first didn't have the smaller boards and subsequently added them. So those were probably from before that time.

Quote
I believe R77 is the 8.2k resistor used for +8 metering and should not be on the main board at all.  Are you getting it confused with R76 (also 8.2K)?  R77 is on the meter PCB for the pushbutton version.

Hmmm... I'm obviously extremely diffused on that one. I'll have to go back and reconnoiter. Sorry.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 15, 2009, 09:28:50 PM
While you are here... I guess it was you who posted the picture of the t-pad from your kit and the wiring thereof? Is that still valid now on the latest and greatest?
Title: Re: 1176LN Rev D DIY
Post by: Skylar on June 15, 2009, 09:42:20 PM

2. I noticed in Skylar's wiring guide that there were some resistors and caps wired into the attack pot I think it was, but I don't see those in the Rev D rotary wiring guide. Is that some optional or just something from a previous rev of these boards that is now not requird?



Dean,

You can see these components by taking a look at the schematic (either UREI, mnats, or Purple MC77).

This is from the UREI manual, page 52 of the PDF.
(http://i73.photobucket.com/albums/i222/skylargray/1176/th_attack_release_pots-SCH.gif) (http://s73.photobucket.com/albums/i222/skylargray/1176/attack_release_pots-SCH.gif)

mnats uses the same component designations as the UREI in this area, so look for C27, R54, & R57 on your PCBs.
If you can't find these on the PCBs, you will have to wire them to the pots as shown in the wiring diagram.

Title: Re: 1176LN Rev D DIY
Post by: Skylar on June 15, 2009, 09:47:39 PM
Also...

One thing I've tried to mention is that when you're using the wiring guide I put together,
it's highly recommended that you follow the schematic as well because it gives you
a much better understanding of what's going on with the circuit.

A lot of questions can be answered by the schematic.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 15, 2009, 10:19:07 PM
Yes the one you received from mnats is the original board that can be used for various input transformers including the one I sell.  If you are using the transformer I sell then just use the board I sent you.  It's designed by mnats specifically for this transformer, no jumpers needed.
Do you have to use jumpers and that for Mnats board for the Hairball Altran transformers?

I soldered mine with just the molex connectors and the Altran on top, to look exactly like this pic here? Are there more to it???? It does not say on Mnats transformer board to solder any jumpers for the Altran. Can someone please confirm that I have done it correctly?

(http://www.freeimagehosting.net/uploads/8c76eafb7c.jpg)
Title: Re: 1176LN Rev D DIY
Post by: luis on June 15, 2009, 10:39:16 PM
Mike,

.. But doesn´t the altran need some links with the mnats tranformer board?
I don´t have my board right here, but I think there is some legend in the board on how to do it. I made some links on mine.


I need your help guys: I´m pretty sure I have my 1176 wired correctly, checked and checked according to mnats guide with the help of Skylar diagram. However I had the output transformer wrong wired (stupid!) and the R32 burned! I´ve replaced the resistor, but when turn the compressor ON, i only get some noise (not HUM, but a Shhh) but the sound is not passing, there is also no diference changing the Input and output Knobs.

I think there are no shorts, and appart from the R32 that was destroyed, the other components all look fine.

Being certain that the wiring is correct, what would you advise me? I checked the PSU and it´s fine.

Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 15, 2009, 10:47:15 PM
Mike,

.. But doesn´t the altran need some links with the mnats tranformer board?
I don´t have my board right here, but I think there is some legend in the board on how to do it. I made some links on mine.

There are two input transformer boards in question.  The original shipped by mnats that can be used with multiple transformers and does require jumpers for the Altran.  You can identify it by the 5 terminal header on the input side.  Then there is the one mnats designed specifically for the Altran that I ship with the inputs. It's dated "27.01.09" and the has a 2 terminal header on the in and out.  That Altran specific board does not require any links/jumpers.

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 15, 2009, 10:50:48 PM
Is it O.K. to mix and match 2n3707, 2n3708 and 2n5088 on the Rev D board as long as their over 250 hfe? I found a store thats got some in stock of each model and I may be stuck having to mix and match trying to get them all above 250 hfe for the board?

What do you mean that there are links for the board for the Altran. Can someone verify this? I looked at heaps of Rev D Xformer board pics and I can't see any of them using jumpers or links on the Mnats Xformer board. I am using Hairballs Altran Xformer.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 15, 2009, 10:56:16 PM
I'm going to start selling transistors at my store.

I'll have match pairs of 2n5457's starting this Wednesday.

In the next 2 weeks I'll be selling 2N3708's and 2n5088's with high enough HFE's and within 5% of each other.

Hopefully that will provide another option.

Mike

Whats going on with this? It's not on your store?
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 12:13:11 AM
I think you have the new board.  No jumpers needed. 

I have the matched 2N5457's on my store.  I haven't started stocking the 3708 and 5088's yet.  I've been super busy with some new stuff, I will look into this again this week.

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 16, 2009, 05:32:56 AM
I think you have the new board.  No jumpers needed. 

I have the matched 2N5457's on my store.  I haven't started stocking the 3708 and 5088's yet.  I've been super busy with some new stuff, I will look into this again this week.

Mike
This is how my Mnats Xformer board look like. Do they look like the new Mnats one that does not require jumpers or leads for th altran Xformer? I haven't found any instructions on these except what's written on the board.

(http://www.freeimagehosting.net/uploads/92cb651927.jpg)

(http://www.freeimagehosting.net/uploads/a64e1b79cf.jpg)


Title: Re: 1176LN Rev D DIY
Post by: luis on June 16, 2009, 07:40:50 AM
Can the output transformer be damaged if wired wrong? I wired mine wrong and burned the r32 resistor and now i´m afraid that my output tranformer might be damaged.

Also, is it possbile to check if the transformers (input and output) are working with a DMM?


Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 09:26:20 AM
canidoit:
If that is your board then you need to add 2 sets of jumpers.  Luckily the instructions are right on the board.

Luis:
I doubt it's damaged. Lots of people have accidentally wired the OT wrong and had R32 flame up (including me!). 

Mike

Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 16, 2009, 02:08:01 PM
So here are some more dumb questions...

What are the gray dotted lines in Skylar's wiring diagram for? Does that indicate shielded cable I guess?

Also, it's not obvious to a software guy like me just looking at it, but I assume that one of the positions on the meter selection knob in the rotary version is the power off switch for the unit?

And what does NC mean in the diagrams? Obviously they are grounds, but not sure what initials are for. And if it's a ground, why, for instance, does it run over to the meter or ratio board, but show no connection to the meter or ratio board? I'm sure I'd see the answer to this when I go back to the wiring guide, but I'm just pointing out what doesn't make sense as a non-electronics guy, so that maybe it can be clarified in the diagram.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 02:25:03 PM
So here are some more dumb questions...

What are the gray dotted lines in Skylar's wiring diagram for? Does that indicate shielded cable I guess?

Yes.

And what does NC mean in the diagrams? Obviously they are grounds, but not sure what initials are for. And if it's a ground, why, for instance, does it run over to the meter or ratio board, but show no connection to the meter or ratio board? I'm sure I'd see the answer to this when I go back to the wiring guide, but I'm just pointing out what doesn't make sense as a non-electronics guy, so that maybe it can be clarified in the diagram.

You connect one end of the shield to ground because if you connected both you would have a ground loop (or be susceptible to one).

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 16, 2009, 04:25:47 PM
And what does NC mean in the diagrams?
I thought it meant "not connected".
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 04:30:04 PM
And what does NC mean in the diagrams?
I thought it meant "not connected".

Yes, that end is "not connected" to avoid a loop.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 16, 2009, 04:44:37 PM
canidoit:
If that is your board then you need to add 2 sets of jumpers.  Luckily the instructions are right on the board.
OIC, you have to read up to the third line and the ABCDEF is underneath my Altran.

So B to C and E to F
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 05:06:09 PM
And also the the two links for no H-Pad up by the input.
Title: Re: 1176LN Rev D DIY
Post by: luis on June 16, 2009, 09:12:59 PM
I think you have the new board.  No jumpers needed. 

I have the matched 2N5457's on my store.  I haven't started stocking the 3708 and 5088's yet.  I've been super busy with some new stuff, I will look into this again this week.

Mike

Hey Mike match them all, and I think it would be great if you could sell all the pots and specially the SPDT switch because in Europe is very dificult to find!

Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 16, 2009, 09:17:37 PM
Hi,

I'm working on all of these things right now.

I'm reviewing pot samples as we speak.  Stocking the right pots will take a huge investment.  It is on my list once I get through the next large project.

Transistors with high HFE will come sooner.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 16, 2009, 09:30:04 PM
Why do I see in some folk's pictures a 2 watt resistor on one of the wires coming from the power transformer? I ordered it because it's in the BOM, but I don't see everyone using one in the various pics I've looked at, as best I can tell.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 16, 2009, 09:36:44 PM
My other dumb ordering snafu was that somehow I ordered a freaking 19" deep enclosure. So it gigantically larger than required. I could move into it basically. Oh well, at least I shouldn't have any hum issues. I can keep the power transformer about a quarter mile from the other components.
Title: Re: 1176LN Rev D DIY
Post by: luis on June 16, 2009, 09:45:36 PM
Why do I see in some folk's pictures a 2 watt resistor on one of the wires coming from the power transformer? I ordered it because it's in the BOM, but I don't see everyone using one in the various pics I've looked at, as best I can tell.

I think you are refering to the meter lamp, wich need 2 watt resistors.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 16, 2009, 09:47:06 PM
And more dumb questions... Whose POV are the Input/Output designations on the Hairball input xformer board? So the XLR/T-Pad go to the Input terminals and the Output terminals go to the input on the main board?
Title: Re: 1176LN Rev D DIY
Post by: luis on June 16, 2009, 09:50:29 PM
My other dumb ordering snafu was that somehow I ordered a freaking 19" deep enclosure. So it gigantically larger than required. I could move into it basically. Oh well, at least I shouldn't have any hum issues. I can keep the power transformer about a quarter mile from the other components.

 ;D Yeah, but the giant case will not come pre-grounded!
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 16, 2009, 11:10:53 PM
Why do I see in some folk's pictures a 2 watt resistor on one of the wires coming from the power transformer? I ordered it because it's in the BOM, but I don't see everyone using one in the various pics I've looked at, as best I can tell.

I think you are refering to the meter lamp, wich need 2 watt resistors.

So they are piggybacking that onto two of the power transformer inputs into the board?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 17, 2009, 12:14:40 AM
Why do I see in some folk's pictures a 2 watt resistor on one of the wires coming from the power transformer? I ordered it because it's in the BOM, but I don't see everyone using one in the various pics I've looked at, as best I can tell.

I think you are refering to the meter lamp, wich need 2 watt resistors.

So they are piggybacking that onto two of the power transformer inputs into the board?
This is a better view. I have seen that big chunky resistor on the left side as well. I think it's both AC on both 1st and 3rd of the Molex. From the pics I have gathered, it goes to the VU lamp. Measure the power coming from the wire going to the 1st and 2nd molex and see if it comes out with 35 volts. The 220 ohm 5 watt resistor is to downgrade the 35 volts to 11.78 volts for the lamp. I haven't gone that far with my build but if those wires to the molex pulls out 35 volts, then I guess thats where the 35 volts are being sourced for the VU lamp for the 220R resistor. Wait till someone can confirm this before trying it incase I am wrong???
(http://www.freeimagehosting.net/uploads/1776764dd6.jpg)
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 17, 2009, 01:45:40 AM
That is the voltage dropping resistor for the VU lamp.

The secondary is wired with a center tap (0V).  The voltage between either side of the secondary and the center tap is 25V.  So set your DMM to AC and put your + on either the right or left terminal, then your - on the center terminal and you should get roughly 25V.

Your lamp likes 11V and it doesn't care if it's AC or DC.  Here's where Ohm's Law (V = IR) drops by to help us.

We need to drop the voltage by 14V.  I know my VU is drawing about 0.063A.

R=14/0.063A
R= 222R

There is really no need to guess.

Edit:

Also, if P=V*A, then in this case we've got about 1W of power.  A 2W resistor should do.

Mike
Title: Re: 1176LN Rev D DIY
Post by: luis on June 17, 2009, 10:20:45 AM
....

Luis:
I doubt it's damaged. Lots of people have accidentally wired the OT wrong and had R32 flame up (including me!).  

Mike

Well, my compressor passed sound before, the meter moved (when I had the OT correctly wired) and now after burning the  R32 due to ot wired wrong , the sound does not pass neither the meter moves.
I already unsolder all transistors, and will try again with new transistors. My doubts:

- even with the transistores damaged should the sound pass?
Can the wrong OT wiring damage other components beside R32?

Thanks
Title: Re: 1176LN Rev D DIY
Post by: carnitas on June 17, 2009, 04:31:16 PM
luis, FWIW, i burned R32 twice and after i got my wiring figured out everything works fine.  The first time I burned R32 i didn't realize what i had done and left the unit on for a minute before i figured it out.
Title: Re: 1176LN Rev D DIY
Post by: luis on June 17, 2009, 07:24:05 PM
Thanks for the response, but something must been  damaged beside R32.

I also replaced all transistors, but no sound, no meter and everything is microphonic: Do you know that technique to check tubes in guitars amps, by tapping them with a pencil? If I tapp anywhere in the case, board, tranformer I can here the sound!

I don´t know what more to do. The psu voltages are fine.

Are the reference voltages for the rev D the same for the others versions? Should I check them?

Thank you
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 17, 2009, 07:44:02 PM
I'd go over all the wiring again very carefully.

Mike
Title: Re: 1176LN Rev D DIY
Post by: phatmateo on June 17, 2009, 07:48:29 PM
if you can hear a sound when you tap the case, then its probably a grounding issue as well as whatever issue you have that's not passing signal.  Use Skylar's wiring diagram and triple check everything
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 17, 2009, 07:54:38 PM
Thanks for the response, but something must been  damaged beside R32.

I also replaced all transistors, but no sound, no meter and everything is microphonic: Do you know that technique to check tubes in guitars amps, by tapping them with a pencil? If I tapp anywhere in the case, board, tranformer I can here the sound!

I don´t know what more to do. The psu voltages are fine.

Are the reference voltages for the rev D the same for the others versions? Should I check them?

Thank you
Do a high res photo of different angles of your build and post it up. Maybe someone visually can pick up what's wrong with it. Close up photos of sections like pots wiring, meter wiring, pcb board close up, xformer close up, etc. get good lighting when taking the photos so it comes out clear. Also take a pic of the underneath in all angles.
Title: Re: 1176LN Rev D DIY
Post by: luis on June 17, 2009, 08:00:12 PM
I will try to put take some pictures tomorrow, but I´ve checked every wire. I´me pretty  sure there is something is damaged in the board,

thanks
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 17, 2009, 08:08:30 PM
I ordered the matrix pins from the BOM. I just got to the point of being ready to put them in and noticed that they are crimp on pins on the male side, not the sort with tails to go through a PCB board. I looked and the picture for the P/N indicated in the BOM would indicate that they are through board tails, but that's not what I got. Anyone else have this problem?

If it's just an error on Mouser's part, I'll just order some more. But I don't want to pay 2 day shipping just to get the same wrong stuff again. But if I don't get them in this week, it'll be yet another week before I get this thing put together.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 17, 2009, 08:42:10 PM
I ordered the matrix pins from the BOM. I just got to the point of being ready to put them in and noticed that they are crimp on pins on the male side, not the sort with tails to go through a PCB board. I looked and the picture for the P/N indicated in the BOM would indicate that they are through board tails, but that's not what I got. Anyone else have this problem?

If it's just an error on Mouser's part, I'll just order some more. But I don't want to pay 2 day shipping just to get the same wrong stuff again. But if I don't get them in this week, it'll be yet another week before I get this thing put together.

If you have the push button PCB boards from Hairball, it uses the little connectors instead which is far better.
(http://www.ine-kpro.com/diy/1176/images/vu.jpg)

The female or male should be crimp for cables and the other PCB board version to be soldered onto the PCB.
(http://www.ine-kpro.com/diy/1176/images/pins.jpg)
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 17, 2009, 09:12:43 PM
I'm doing the rotary version, and both sets of pins are crimp on types in my case.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 17, 2009, 09:59:23 PM
I'm doing the rotary version, and both sets of pins are crimp on types in my case.
OIC, Well I got the soldered version on my male matrix for my BOM list, though it does not look like the bottom pic I have attched. It looks like the connector pin versions. I actually prefer the one in the bottom pic for matrix pins.

This is the Mouser part number I got.

pcb mount   matrix pins   rotary and meter board   
538-02-06-8103 – Molex $0.13 US Male Solder tail

wire end   female connectors   for pins above   
538-02-06-1103 Molex $0.09 US Female Crimp terminals
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 17, 2009, 10:43:29 PM
Then it looks like Mouser sent me the wrong ones then. Oh well. Screw it, I'm probably just going to hard wire it. Live fast, die young and all that. It'll probably be more robust in the end anyway.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 17, 2009, 11:28:31 PM
So, on the power transformer, the two 0s are twisted and go into the center connector and the two +25s go to the outside connectors, right? All the pictures seem to be using a different transformer, so I can't get any hints from them and I can't get anything out of the schematic that would make it obvious to me if my guess is right.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 17, 2009, 11:54:56 PM
http://www.diyfactory.com/data/transformer_connections.gif

Check out the split secondary w/ center tap image here, then look at the color code guide that should be on your transformer or datasheet.

The center tap (0V) to the middle terminal and the 25V to the right and left.

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 17, 2009, 11:56:34 PM
Then it looks like Mouser sent me the wrong ones then. Oh well. Screw it, I'm probably just going to hard wire it. Live fast, die young and all that. It'll probably be more robust in the end anyway.
You can pick them up at your local electronics store. They are called in Australia as PCB Pins and PCB sockets for easy termination. I have always been told that hard wire is better anyways.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 18, 2009, 12:04:07 AM
For the ground wire that's on the side wall of the output transformer, should that just be grounded to the screw holding the transformer to the case or just ignored because the grounding is being handled by the star ground at the input XLR already?

And the xformer would seem to have an extra pair of wires (yellow and orange), The are just to be ignored?

Blue and red go off to the XLR, and the other 6 are paired up in sets one from each side of the transformer, as per the wiring diagram.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 18, 2009, 12:23:58 AM
For the ground wire that's on the side wall of the output transformer, should that just be grounded to the screw holding the transformer to the case or just ignored because the grounding is being handled by the star ground at the input XLR already?

I connected it to the signal chassis ground.  I'm not sure if that is the best practice.

And the xformer would seem to have an extra pair of wires (yellow and orange), The are just to be ignored?

They get connected directly together.

Blue and red go off to the XLR, and the other 6 are paired up in sets one from each side of the transformer, as per the wiring diagram.

Yes.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 18, 2009, 01:35:15 AM
Here's the Altran Links setup. Correct me if I am wrong.

(http://www.ine-kpro.com/diy/1176/images/altran/altranLinks.jpg)

Lift to prevent solder bleed
(http://www.ine-kpro.com/diy/1176/images/altran/altranLinks2.jpg)
Title: Re: 1176LN Rev D DIY
Post by: fazeka on June 18, 2009, 03:01:06 PM
What tools did you use to cut those out perfectly.

Hole saw and a couple of files. Most important tool was patience.  ;D
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 18, 2009, 03:22:24 PM
Well, I checked Radio Shack, Fryes, and the bulk electronics supply stores, and no matrix pins. So I'm just going to hard wire it. I'm a loner, a rebel...
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 18, 2009, 10:49:26 PM
And the xformer would seem to have an extra pair of wires (yellow and orange), The are just to be ignored?

They get connected directly together.

Blue and red go off to the XLR, and the other 6 are paired up in sets one from each side of the transformer, as per the wiring diagram.

Yes.

And on the high voltage side, we just pair up one side from each set and connect them arbitrarily to the left and right side IEC socket pins, right? I assume since it's AC there's no polarity to that?
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 18, 2009, 11:05:03 PM
Nevermind, I was looking at the pictures, but the wiring diagram shows only one set being used and going through the meter board. I assume that's some difference between the rotary and push button versions, though it seems odd that they wouldn't go through the push buttons in that case. It also seems a little strange to push 110V through that little PCB board?
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 18, 2009, 11:27:53 PM
OK, now I'm completely confused before even starting. There are no A/B connectors on my meter board, so obviously the wiring diagram is way out of date relative to the latest boards and I should just be ignoring it and going by the wiring guide HTML page I guess. And I guess that's why I was seeing what I was seeing in the pictures.

It sure would be nice if there was a similar diagram that was up to date and for the rotary version.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 03:49:00 PM
So, on the Hairball t-pad, is there still a need to put the two resistors between the poles, or is that something specific to the type of t-pad that Skylar was using? All the other pictures I've seen are with that round t-pad. It wouldn't appear to be the case, but I figured I should ask...
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 19, 2009, 06:30:00 PM
No resistors needed with the 3 deck Clarostat t-pad I sell.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 19, 2009, 06:57:57 PM
So, on the Hairball t-pad, is there still a need to put the two resistors between the poles, or is that something specific to the type of t-pad that Skylar was using? All the other pictures I've seen are with that round t-pad. It wouldn't appear to be the case, but I figured I should ask...
Here's a better view.
(http://www.ine-kpro.com/diy/1176/images/tpad.jpg)
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 08:20:40 PM
Where are the X & Y pads on the main board? The wiring guide indicates X&Y from the main board to the X&Y on the meter board, but I don't see any X&Y. Of course they are all covered by the Molex connectors so I'm going by the picture in the PDF, but I don't see any such pads in the picture.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 19, 2009, 08:28:42 PM
Where are the X & Y pads on the main board? The wiring guide indicates X&Y from the main board to the X&Y on the meter board, but I don't see any X&Y. Of course they are all covered by the Molex connectors so I'm going by the picture in the PDF, but I don't see any such pads in the picture.

On the revision A&D the meter X Y pads connect to the XLR output + and -.

You can go X pin 2 and Y to pin 3 or the other way around, doesn't matter.

Mike 
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 19, 2009, 09:11:57 PM
So many questions seem to get asked that are easily answered by simply looking at the original schematic. Believe it or not, this ancient relic is the most up-to-date document available* and contains the complete wiring diagram for the 1176.

Similarly, so many problems seem to be caused by people using drawings or pictures that are either inaccurate for the board version, misinterpreted or simply wrong. I'm sure these drawings and pictures were done with good intentions, but armed with the relevant PDF from my site and the correct schematic from the JBL site you can be assured that you have the correct information.

Just for example and not to single anyone out:
Quote
Where are the X & Y pads on the main board?
If you look at the schematic, you would see that X and Y are on the secondary of the output transformer. Since the output transformer is mounted directly on the board with the G1176 and similar, there are pads that connect to the secondary on the main board. But since the Rev D has a huge output transformer mounted off-board there won't be any pads connecting to the secondary as those wires are hanging off the back of the transformer waiting to be connected directly to the output and VU meter switch.

*aside from the addition of the newer power supply and a trimmer for R44 instead of a fixed, selected resistor mentioned on my Rev D page - neither of which affects the wiring in any way.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 09:33:41 PM
I understand what you are saying, but I'm not a hardware guy. I wouldn't trust anything I felt I understood about the schematic. It may seem dumb to you, but you come over to my side of the street (software) and I'll give you a diagram and inheritance hierarchy of a software program and ask you to create it from that diagram. And when you ask me, what's an overloaded method, I'd say, look at the diagram, it's obvious if you just read that diagram. But of course it wouldn't be obvious to you because you probably don't know much about software and the diagram wouldn't mean much to you.

So you have to make allowances for people coming to this from completely different worlds. And people who are doing this, not because they enjoy it, but because it's the only way they can afford good equipment, and who cannot afford to buy new stuff if they blow the current ones up. So we tend to be very cautious.

It would really only take one diagram, like Skylar's but up to date and appropriate for the rotary version. That's all that would be required and people like me could do this easily. That would mean something to someone like me. A schematic means very little to me. I'm perfectly capable of following instructions and stuffing a board, but I don't feel comfortable improvising or assuming that I understand something that's not explicitly stated.

If you would make the modest effort required to create such easy to follow instructions, you could sell a lot more and charge considerably more because then it wouldn't be something that only electronics geeks would feel comfortable doing. I built SCA pre-amps and an LA-2A from Drip without any problems, and they are great. I paid $250 for the board and T4 cell for the LA-2A and it was a bargain at that. If you would make it easier to build these things you could actually make some money, and the effort to do so wouldn't be very large at all.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 09:38:24 PM
Where are the X & Y pads on the main board? The wiring guide indicates X&Y from the main board to the X&Y on the meter board, but I don't see any X&Y. Of course they are all covered by the Molex connectors so I'm going by the picture in the PDF, but I don't see any such pads in the picture.

On the revision A&D the meter X Y pads connect to the XLR output + and -.

You can go X pin 2 and Y to pin 3 or the other way around, doesn't matter.

Mike 

In addition to the output transformer blue/red wires that are already going to the output XLR connections?
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 19, 2009, 09:45:48 PM
Here's a better view.

Sorry to interrupt, but I just thought I'd say (I'm assumeing from what I've read earlier that you are are relatively new to this) your build looks neat and clean. Good work; it makes things so much easier in the long-run.

Roddy
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 19, 2009, 10:01:06 PM
So you have to make allowances for people coming to this from completely different worlds. And people who are doing this, not because they enjoy it, but because it's the only way they can afford good equipment, and who cannot afford to buy new stuff if they blow the current ones up. So we tend to be very cautious.

Right, and would you be able to tolerate a newbie sitting next to you asking newbie software design questions for days on end?

Probably not, you'd tell them to go study the basics and get back to you.

I managed to get an 1176 up and running with all of the documents you have available to you. Mnats site is invaluable in that regard as is this one. The forum search function, not the google search function works quite well.

People here will tend to push you in the direction of learning something, not just push you along on a paint by numbers happy hour path.

http://www.geocities.com/m_natsume/1176-wiring.html

is as close to a step by step, hold you hand tutorial as your going to get, it's very good.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 10:52:53 PM
Right, and would you be able to tolerate a newbie sitting next to you asking newbie software design questions for days on end?

Probably not, you'd tell them to go study the basics and get back to you.

I'm quite capable of such things, because I do it all day every day to help the people who use our product. I understand that the product is a means to an end, not an end in itself to most people.

Quote
http://www.geocities.com/m_natsume/1176-wiring.html

is as close to a step by step, hold you hand tutorial as your going to get, it's very good.

Mark

But for a different and/or much older revision of the board or one of the other 1176 revisions.


Hell, if you guys will help me out, I'll do the freaking diagram when I'm done. It would take like a whole couple of hours and make it far easier for people to do this. Keep in mind, some of us don't really want to learn a lot. We are musicians and we need gear to make music. Our expertise is in other things (software in my case), and we'll likely never use any of this ever again, or very lightly at best. So it's not like it's a very useful time investment to try to become expert in something we never do. Not that I'm against learning anything in general, I'm very inquisitive. But there's only so much time in life and this isn't something that will benefit me very much in the future.

Given that one little diagram would let anyone build one of these things who can follow basic instructions and solder, without much trouble, and no such diagram exists out of all the people who have done it, that's pretty shocking to me. Give people a really good experience building something, and then those who want to learn more will be much encouraged to do so, and those who are just doing it for the gear will be able to get it done and not bother you.
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 19, 2009, 11:17:51 PM
I'm quite capable of such things, because I do it all day every day to help the people who use our product.
That's a customer, not a co-worker, different ball game.

I did customer support a long time ago and I don't envy your position. 1 minute of silence please. :)

Quote
But for a different and/or much older revision of the board or one of the other 1176 revisions.

Errr, well mine was a Rev J and I don't think the wiring guide for Rev D is any different, perhaps MNats can confirm that.

Quote
Keep in mind, some of us don't really want to learn a lot. We are musicians and we need gear to make music. Our expertise is in other things (software in my case), and we'll likely never use any of this ever again, or very lightly at best. So it's not like it's a very useful time investment to try to become expert in something we never do.

Your X/Y meter question doesn't require anything but a little ambition and some back tracking to solve. I would suggest removing the connectors that are covering your board and taking a picture of the PCB, you will then have a reference for wiring the pads. This is simple common sense.

No one said you need to become an expert, quite the contrary. There are people here who are far more gifted in that respect than I'll ever be, but I managed to get my 1176 up and running by spending the time necessary to understand what was going on and looking at all the resources available to get me through it.

If this isn't to your liking, perhaps a commercial product is more up your alley.

Mark
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 19, 2009, 11:23:10 PM
I didn't create this project to make it easy to create a cheap 1176, to make lots of money or any of the reasons that some people seem to think I should have.

When I designed the boards there was no Rev D thread, no drawings, no pictures of DIY units, no endless T attenuator threads, just a schematic. I'm no electronic genius, just a guy who had a little time and motivation to try out building this thing. The boards were laid out to closely match the schematic as a way to encourage learning (with all due respect, the G1176 is very confusing to trace in comparison). The documentation that I created is all done for the same reason which is why I don't say exactly which component you should buy in the BOM. You learn more by trying things out, making a few mistakes, looking at the voltages involved when choosing electrolytics etc.

So you see, if it seems as though I am making things tough on the guy who just wants some cheap gear it's because that was never the intention. In my opinion DIY is a very bad way to save money as many here will attest.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 11:30:20 PM
Quote
So you see, if it seems as though I am making things tough on the guy who just wants some cheap gear it's because that was never the intention. In my opinion DIY is a very bad way to save money as many here will attest.

Are you kidding? It's a GREAT way, if some very basic instructions are provided. As I already indicated, I built two SCA pre-amps (way more challenging that this project in terms of soldering and tedious and careful work) and the Drip LA-2A. They went very well and I have now probably $5K worth of stuff for an investment of about $1500. This one will cost me about $600'ish, while a store bought one costs $2500. So that'll be more like $8000 worth (if you include the DI SCA DI board as well) for about $2100 of investment or so.

So it's an incredible way to save money for people who don't have the bucks to buy the real stuff. The whole point of this stuff is to make music, not to understand electronics. It's fine if someone wants to, and I'd be the first person to encourage them if that's why they want. But the point of a compressor is to make music and that's what I want it for.

I've been pushing the Drip guy to do an 1176, but other folks were saying why bother because this one was available. But with the kind of excellent instructions he provides, almost no one would ever come here if he did one because his would be so much easier to do. He provides a lot more than a diagram, but in terms of the wiring for this one, just one diagram would be all it would take to save folks from making a lot of mistakes.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 19, 2009, 11:32:48 PM
Quote
That's a customer, not a co-worker, different ball game.

I did customer support a long time ago and I don't envy your position. 1 minute of silence please.

Allow me one moment of chest thumping ego here... :-) I'm not in customer support. I created the entire 800,000 lines of code that make up the product (www.charmedquark.com). But it's a very complex product and everyone who buys it, no matter how techical, needs a lot of spinup help. So I spend a lot of time every day, on top of all the coding and documentation stuff I do, helping people and answering questions, most of which are fairly common ones because everyone goes through the same spin up pretty much.

Quote
Your X/Y meter question doesn't require anything but a little ambition and some backtracking to solve. I would suggest removing the connectors that are covering your board and taking a picture of the PCB, you will then have a reference for wiring the pads. This is simple common sense.

It's not about whether I can stare at the schematic and come up with what I think might be the right answer. It's about I cannot afford to fry this thing when I plug it in, or destroy the pads by repeated desoldering, or I will have flushed this money down the drain and there's no more to try again, so I want to be SURE I've hooked it up right, not think I hooked it up right. I mean, how hard is that to understand?
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 19, 2009, 11:58:55 PM
It's not about whether I can stare at the schematic and come up with what I think might be the right answer. It's about I cannot afford to fry this thing when I plug it in, or destroy the pads by repeated desoldering, or I will have flushed this money down the drain and there's no more to try again, so I want to be SURE I've hooked it up right, not think I hooked it up right. I mean, how hard is that to understand?

Well the only way to be sure is to de-solder those connectors that you placed prematurely.

It's called learning.

If you don't have the confidence to de-solder a few connectors to solve a problem, then perhaps this project isn't for you.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 12:09:16 AM
Well the only way to be sure is to de-solder those connectors that you placed prematurely.

It's called learning.

If you don't have the confidence to de-solder a few connectors to solve a problem, then perhaps this project isn't for you.

Mark

I don't get your point. De-soldering all the Molex connectors (more like 12 of them not a few, and they wouldn't have been easy at all because of their widely spaced multi-pin configurations and the fact that you can't get a vacuum to one side while heating on the other) wouldn't have solved anything because there'd have been no X/Y connector under them, nor should it be required because I have the numbered layout of the board in the PDF file, which already told me there's no X/Y connector on the board, which is why I asked.

As to this project, it is for me, since I've already bought all the parts.

And the last I checked, one of the best ways to learn is to ask someone who knows, because they've already done it. Geez...

Title: Re: 1176LN Rev D DIY
Post by: mnats on June 20, 2009, 12:36:16 AM
Your questions are getting lost in the banter.
Quote from: Dean Roddey
In addition to the output transformer blue/red wires that are already going to the output XLR connections?
Yes, the X Y points are the output to the XLR. Your VU meter gets strapped across this output (through the standard 3.6k resistor) via the switch. Connect the X Y points on the rotary board to the output wires as Mike advised.

Back to the banter:
Quote from: Dean Roddey
So it's an incredible way to save money for people who don't have the bucks to buy the real stuff.
Only if your time isn't worth much. But I suspect you command a decent hourly wage for the same time spent writing code. Given the time spent, are you really saving that much?

Quote from: Dean Roddey
Hell, if you guys will help me out, I'll do the freaking diagram when I'm done.
If your offer to make one is genuine, I'm sure we will all be happy to pitch in and help if you post it when it is finished.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 12:58:15 AM
Only if your time isn't worth much. But I suspect you command a decent hourly wage for the same time spent writing code. Given the time spent, are you really saving that much?

Well, the great thing about running your own startup company is that you get to work 10 times as hard for 10 times less money, so buying wasn't an option. Building was the only option. I sold off my store bought equipment and Waves Platinum to finance it, so there's a fixed kitty to do it on. And if any of them blew up, that would have been a loss of the store bought stuff and nothing to replace it.

Quote
If your offer to make one is genuine, I'm sure we will all be happy to pitch in and help if you post it when it is finished.

Absolutely. I'm pretty adept at Adobe Illustrator. It wouldn't be too hard to whip up a guide similar to Skylars but more up to date and for the rotary version.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 01:01:06 AM
One that I think is obvious, but maybe it's not is the Gnd on the meter board. In all the other stuff, you are warned not to hook up the other side of the shielded cable from Gnd/22. But it would appear in this newer board that you are supposed to hook it up, so I did. It would be nice to know that's correct before I commit to putting the meter board onto the POT and soldering it in, which I'm close to ready to do.
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 20, 2009, 01:53:37 AM
One that I think is obvious, but maybe it's not is the Gnd on the meter board. In all the other stuff, you are warned not to hook up the other side of the shielded cable from Gnd/22. But it would appear in this newer board that you are supposed to hook it up, so I did.
(http://mnats.net/images/pad22_23.gif)
Look at the schematic above. Point 22 is the input to the gain reduction amplifier.

On the rotary meter boards the switch labeled S9 is incorporated into the rotary switch (on the original it is located on the attack potentiometer). In order to disable the gain reduction, the input of the gain reduction amplifier is shunted to ground, point 23 on the schematic. That thing that looks like a tube to the right of point 23 is the shield of the cable running to pad 22.

So yes, the shield connects to ground. Coincidentally, there is a ground pad right next to pad 22 on the main board.
Quote from: Dean Roddey
It would be nice to know that's correct before I commit to putting the meter board onto the POT and soldering it in, which I'm close to ready to do.
Please do not put the meter board onto a pot. The only thing on the board should be one resistor and a rotary switch.

Quote
If your offer to make one is genuine, I'm sure we will all be happy to pitch in and help if you post it when it is finished.

Absolutely. I'm pretty adept at Adobe Illustrator. It wouldn't be too hard to whip up a guide similar to Skylars but more up to date and for the rotary version.

I'm going to hold you to that.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 02:05:33 AM
So yes, the shield connects to ground. Coincidentally, there is a ground pad right next to pad 22 on the main board.

I'm not doing the pins, I'm soldering them in, so just to make sure I grok what's going on... I can run one shielded between Gnd/22 on the main board to Gnd/22 on the meter board. Then 7 on the main board can be a single stranded to 7 on the meter board?


Quote
Please do not put the meter board onto a pot. The only thing on the board should be one resistor and a rotary switch.

That's what I meant, sorry. I'm about ready to commit to putting the board onto the rotary switch and solder it in.


Quote
I'm going to hold you to that.

No need to do that, I'll hold myself to it. I have no problem contributing back if I'm helped out. I've been encouraging people heavily on Gearslutz and the SONAR forum to get involved and answering lots of their questions about how hard these things are from the perspective of a non-electronics person and what all is involved and all that. I'm not just mooching here or anything. I'm actually getting a lot of people interested in it who wouldn't otherwise be, because they see someone like themselves able to do it.

http://www.gearslutz.com/board/good-news-channel/392034-woohoo-first-step-down-diy-path.html
http://forum.cakewalk.com/tm.asp?m=1728558

But I can pretty much guarantee you that most of them are interested in it only as a means to an end, i.e. to make better music, and not in the electronics for its own sake.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 20, 2009, 02:21:08 AM
I have to agree with some of Deans points here.

Why would anyone risk their investment if they can get some form of affirmation or help from someone who knows more. I mean, once you cause a fault by an error in the way you have built your unit, it could end up costing you more in time trying to troubleshoot afterwards or you could give up hope fixing it and end up with an expensive paper weight.  :o

BTW, the pic was only to show that the Hairball T-Pad didn't require resistors as shown in one example.
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 20, 2009, 04:14:37 AM
Quote from: Dean Roddey
I'm not doing the pins, I'm soldering them in,
I never mentioned anything about pins.
Quote from: Dean Roddey
...so just to make sure I grok what's going on... I can run one shielded between Gnd/22 on the main board to Gnd/22 on the meter board.
Yes, there is a 22 and a ground on the meter and main board. The shield goes to ground and the 22 goes to the center conductor on each side of that cable.

If you left either ground (edit)unconnected there would be no path for the input of the gain reduction amplifier to connect to ground via the switch. In certain instances, this might cause interference to inject itself into the gain reduction amplifier causing spurious gain reduction where none is wanted.
Quote from: Dean Roddey
Then 7 on the main board can be a single stranded to 7 on the meter board?
Armed with the knowledge I attempted to impart previously, look at this part of the schematic which represents the connection of point 7 to the main PCB:
(http://mnats.net/images/point7_9.gif)
The "tube" connected to point 9 represents the ______? (Hint: on the v2.2 boards there is a ground pad next to pad 7).

On the other side of this wire it connects to the attack pot as shown below:
(http://mnats.net/images/point7_attack_pot.gif)
Note that the tube is not connected to anything at this point, but that it does extend nearly to the attack pot clockwise lug. You can attach this wire to the rotary board which in turn connects to the pot.
Quote from: Dean Roddey
I'm actually getting a lot of people interested in it who wouldn't otherwise be, because they see someone like themselves able to do it.

http://www.gearslutz.com/board/good-news-channel/392034-woohoo-first-step-down-diy-path.html
http://forum.cakewalk.com/tm.asp?m=1728558

But I can pretty much guarantee you that most of them are interested in it only as a means to an end, i.e. to make better music, and not in the electronics for its own sake.
As previously mentioned I'm not interested in selling more boards to people who have no interest in electronics. Those who aren't interested in electronics can stay at Gearslutz for all I care. My intention here is to have those drawings posted so that those that are not interested in electronics don't have to ask questions answered by the inscrutable schematic or that require valuable minutes of searching the forum to find the answers to ;D.
Title: Re: 1176LN Rev D DIY
Post by: jdbakker on June 20, 2009, 05:06:13 AM
But I can pretty much guarantee you that most of them are interested in it only as a means to an end, i.e. to make better music, and not in the electronics for its own sake.

Then maybe this isn't the place for them.

JDB.
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 20, 2009, 11:04:26 AM
I don't get your point. De-soldering all the Molex connectors (more like 12 of them not a few, and they wouldn't have been easy at all because of their widely spaced multi-pin configurations and the fact that you can't get a vacuum to one side while heating on the other) wouldn't have solved anything because there'd have been no X/Y connector under them, nor should it be required because I have the numbered layout of the board in the PDF file, which already told me there's no X/Y connector on the board, which is why I asked.

My point is that you shouldn't be afraid to back track if need be.

Quote
And the last I checked, one of the best ways to learn is to ask someone who knows, because they've already done it. Geez...

Right, but if the answer involves you doing a bit of homework then I'd be inclined to point you back to where you came from.

I've spent 17 years to learning to make records, most of that time was spent reading and experimenting until I got the result that I wanted. It took about 15 years to figure out what the result that I wanted was.

I wish you good luck.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 11:28:54 AM
I never mentioned anything about pins.

I meantioned them, the point being that I'm soldering everything in, so I want to be sure before I do it. Once the board is soldered onto the rotary switch it's going to be a lot more of a PITA to change it.

Quote
Yes, there is a 22 and a ground on the meter and main board. The shield goes to ground and the 22 goes to the center conductor on each side of that cable.

I got that. That's already done.

Quote
If you left either ground connected there would be no path for the input of the gain reduction amplifier to connect to ground via the switch. In certain instances, this might cause interference to inject itself into the gain reduction amplifier causing spurious gain reduction where none is wanted.

Which 'either' are you referring to here?

Quote
Armed with the knowledge I attempted to impart previously, look at this part of the schematic which represents the connection of point 7 to the main PCB:

Sorry, but I have no idea what the answer is based on what you just said. There's one connector for 7 on each side, but in the rotary wiring guide it looks like you are really sharing a common ground between the two, as best I can tell. But clearly that's no longer applicable for the version I'm doing.

Given that there's only 1 connection for 7 on the meter board, and that 7 is nowhere near the ground connector on the main board, it wouldn't seem like you'd use a shielded cable, and what good would using a shielded cable be if neither side of the shield is connected? If one side should be connected, which side should it be? There's not another connection on the meter board to connect to.

And I'm not sure what the relevance of the attack pot is, since 7 is going to the board, not the attack pot.

There is a ground connector next to 7, but it's not covered by a Molex connector on my system or any that I've seen pictures of, so I didn't think it got used. Are you saying that the shield on the main board side should go to that non-molex'd ground connector?

Quote
As previously mentioned I'm not interested in selling more boards to people who have no interest in electronics. Those who aren't interested in electronics can stay at Gearslutz for all I care. My intention here is to have those drawings posted so that those that are not interested in electronics don't have to ask questions answered by the inscrutable schematic or that require valuable minutes of searching the forum to find the answers to ;D.

Well, I think that's a bad attitude, but it's yours to have if you want. Do you actually make music? If so, and you go to a place like Gearslutz and ask about ways to achieve some sound and someone just posts a link to a song that sounds like that and says if you can't figure it out from that, then maybe making music isn't for you, what kind of attitude would that be?

As ugly as it can get sometimes, Gearslutz folks are generally very happy to help newbies whose goal is to make music. I sat down last night and answered pretty extensively the 78123781491273'th post about recording levels in the digital world. I could have just said use the search, but that would have turned up a hundred threads, all of them basically arguments, which wouldn't have helped him at all really. He'd have been more confused after reading them than less.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 11:29:40 AM
But I can pretty much guarantee you that most of them are interested in it only as a means to an end, i.e. to make better music, and not in the electronics for its own sake.

Then maybe this isn't the place for them.

JDB.

It probably isn't, but the reason is not because of them.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 11:32:32 AM
Quote
I've spent 17 years to learning to make records, most of that time was spent reading and experimenting until I got the result that I wanted. It took about 15 years to figure out what the result that I wanted was.

That's my point though. I'm interested in MAKING MUSIC, not electronics. I'm perfectly happy to spend hours upon hours studying up on the subject of making music, or trying experiments, because that's what I want to do. And I'm a very technical guy, and I know how the equipment I use works and I understand the technology. But this 1176 is purely a tool for me. I have no interest in it in itself. I know perfectly well how to use it to make music, which is what is important to me. Hours and hours spent getting this figured out are hours I'm not using it to make music.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 12:42:36 PM
So, what I did, and I hope it's right, is the shield to the ground pad beside 7, red to 7, then red on the ratio board to 7.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 12:50:47 PM
So one question that no one really ever answered are the high voltage side of the power transformer. Do both of them need to be hooked up? It appears from others I've seen with the newer boards is that you connect up both dotted ones to L and both undotted ones to N, right? This one would seem to be very important to get right so as not to blow up something.

And, just as a side bar question... Why is there no fuse in this guy?
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 20, 2009, 01:42:28 PM
Quote
I've spent 17 years to learning to make records, most of that time was spent reading and experimenting until I got the result that I wanted. It took about 15 years to figure out what the result that I wanted was.

That's my point though. I'm interested in MAKING MUSIC, not electronics. I'm perfectly happy to spend hours upon hours studying up on the subject of making music, or trying experiments, because that's what I want to do. And I'm a very technical guy, and I know how the equipment I use works and I understand the technology. But this 1176 is purely a tool for me. I have no interest in it in itself. I know perfectly well how to use it to make music, which is what is important to me. Hours and hours spent getting this figured out are hours I'm not using it to make music.

You don't need a degree in electrical engineering to put together the 1176. Patience, common sense and making a few mistakes gets you most of the way there. Brow beating the collective brain trust of this group is not going to get you the result you desire, in fact it will serve only to deconstruct the community. I find this place a valuable resource, I'll be damned if I'll sit silent while someone attempts to school everyone on how it should be done.

If making music is your priority then I'd suggest buying an off the shelf product that suits your needs and start making music.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 20, 2009, 01:50:50 PM
So one question that no one really ever answered are the high voltage side of the power transformer. Do both of them need to be hooked up? It appears from others I've seen with the newer boards is that you connect up both dotted ones to L and both undotted ones to N, right? This one would seem to be very important to get right so as not to blow up something.

And, just as a side bar question... Why is there no fuse in this guy?

F' me. SEARCH is your friend.

"power switch 1176" turned this guy up as the very first result.

http://www.groupdiy.com/index.php?topic=34039.msg416385#msg416385

"mains fuse 1176"

Turns this up

http://www.groupdiy.com/index.php?topic=646.msg199026#msg199026

Please do a search before posting.

A word of warning, with the kind of attitude your putting forward your gonna be on many ignore lists sooner than later.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 02:04:01 PM
I didn't ask HOW to do a fuse. I asked WHY doesn't it have a fuse. It's not the same question. You seem to be too busy trying to explain to me why I'm an moron than actually reading the question. And even if I found another thread, it's very difficult to know if the information is up to date with the latest designs, which is one of the big problems with how things are done around here.

Anyway, I will not be bothering you anymore. I'm not coming back because I really don't care to have anything to do with this kind of attitude. So you will not be forced to spend anymore of your time telling me what a moron I am.


Quote
If making music is your priority then I'd suggest buying an off the shelf product that suits your needs and start making music.

I already explained clearly why that wasn't an option, but you probably didn't read that post because there wasn't anyting in that one that you could sneer at.
Title: Re: 1176LN Rev D DIY
Post by: Skylar on June 20, 2009, 02:09:30 PM
Dean,

I think an important thing you're missing is that mnats' 1176 Project is not a commercial product.
When you buy his PCB, you're not buying support (manuals, tech support, email, etc) as with most commercial products.

This is why I think your comparison between mnats' PCB offering and your startup company is an apples »» oranges comparison.
You have a company, selling a software package to consumers, and part of that package is support for your product.
You've got a great support section right there on your website.
[off topic—your software looks really cool!]

Conversely, mnats is simply selling PCBs that have been verified to work if you build it properly.
He specifically states two things in his White Market thread that are relevant in this instance:

1:
Quote
IMPORTANT: Please note that the price above is for boards only. No individual technical or other support is included in the price. All the information offered is posted on my site and in the associated threads linked above.



2:
Quote
Please do not purchase these Rev A boards unless you are comfortable with reading schematics and are prepared to do some reading and to think for yourself!
I know he says "Rev A," but it should be obvious that he talking about all of his boards.

A prerequisite for building this unit is knowing how to read a schematic.

Furthermore, you really should know how to read schematics before you take on any project dealing with electricity.
If you don't know what you're doing, you could potentially kill yourself.
I know the current and voltages we're dealing with in this project are not nearly as dangerous as those in tube gear,
BUT you could easily burn down your house if you don't understand some core electrical concepts (like being able to understand a schematic).



If you were writing a guide on how to develop an automation software package like the one you've built, are you going to want to explain core concepts like variables, functions, data types, pointers, etc. ?
No—you're going to want to assume a basic level of C++ (or whatever language) familiarity and state the expectations you have of your end-users' skill level.

Here, mnats clearly states his expectations of the buyers' skill level.
He asks that you not buy his PCBs if you do not meet this level.

mnats offers a wealth of information on his website on how to wire one of these compressors.
Combine that with schematic-reading skills, and you have more than enough info to build an 1176 on your own.



Contrary to popular belief by new-comers, this forum is NOT about cheap & easy gear.



I am more than happy to offer my advice and help in any way I can.
The wiring guide I made was for myself while I was building this unit...
I've simply shared it here because I thought i might help some people.
It's not like anyone is trying to make some sort of definitive guide to 1176 building.
This project/thread is not an "1176 for Dummies" book.
(http://i73.photobucket.com/albums/i222/skylargray/1176/th_1176_for_Dummies.jpg) (http://s73.photobucket.com/albums/i222/skylargray/1176/1176_for_Dummies.jpg)





Above all, though, I do not intend to offend or be-little anyone with this post.
If I have done so, I offer my most sincere apologies...just trying to help clarify things.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 02:21:55 PM
Furthermore, you really should know how to read schematics before you take on any project dealing with electricity.
If you don't know what you're doing, you could potentially kill yourself.
I know the current and voltages we're dealing with in this project are not nearly as dangerous as those in tube gear,
BUT you could easily burn down your house if you don't understand some core electrical concepts (like being able to understand a schematic).

Skylar,

Thank you for your post.  You have (once again) hit the nail on the head.

I've been following this thread a little and have some pretty strong feelings.  Unfortunately, things are so busy with my day job right now that I haven't had the time to write a thoughtful response.  Skylar's entire post pretty much sums up my feelings.

The part quoted above it really important.  We're not knitting sweaters here.  If you mess something up, it's not an issue of one sleeve being longer than the other.  It's a serious safety issue.

I think having basic schematic reading skills and a grasp of basic electronic concepts is a must.  I also think these basic skills are a must for any musician or producer.  Having these basic skills will be invaluable in the studio or on tour when a piece of gear decides to stop working.

Taking a few hours to read up on these things will go a long way.

Thanks,

Mike

Title: Re: 1176LN Rev D DIY
Post by: mnats on June 20, 2009, 05:39:21 PM
I never mentioned anything about pins.

I meantioned them, the point being that I'm soldering everything in, so I want to be sure before I do it. Once the board is soldered onto the rotary switch it's going to be a lot more of a PITA to change it.

The switch can only go in one way (well, four really, but each way operates identically). Don't worry about soldering it in. I suppose it could also go on the wrong side of the board, but it would be very difficult to get the solder to flow as the pads are only on one side.

Quote from: Dean Roddey
Quote from: mnats
If you left either ground connected there would be no path for the input of the gain reduction amplifier to connect to ground via the switch. In certain instances, this might cause interference to inject itself into the gain reduction amplifier causing spurious gain reduction where none is wanted.

Which 'either' are you referring to here?

My apologies, I meant to write unconnected. I've corrected my post above.

Quote from: Dean Roddey
Quote from: mnats
Armed with the knowledge I attempted to impart previously, look at this part of the schematic which represents the connection of point 7 to the main PCB:

Sorry, but I have no idea what the answer is based on what you just said.

Sorry, I was trying to 'teach you to fish', but now I see that you are truly sincere in your desire to learn nothing about electronics.

You use a shielded wire here and connect the shield to the ground on the main board only.

Quote from: Dean Roddey
Given that there's only 1 connection for 7 on the meter board, and that 7 is nowhere near the ground connector on the main board...

Quote from: Dean Roddey
There is a ground connector next to 7, but it's not covered by a Molex connector on my system or any that I've seen pictures of, so I didn't think it got used. Are you saying that the shield on the main board side should go to that non-molex'd ground connector?

The board you have does or does not have a ground connection next to pad 7?

If it does not you have a version earlier that v2.2, and you can scrape back a bit of the top ground plane to make the connection.

Quote from: Dean Roddey
And I'm not sure what the relevance of the attack pot is, since 7 is going to the board, not the attack pot.

Yes, as I previously stated: "You can attach this wire to the rotary board which in turn connects to the pot." It is a bit circuitous, but "easier" for you.

Quote from: Dean Roddey
Quote from: mnats
As previously mentioned I'm not interested in selling more boards to people who have no interest in electronics. Those who aren't interested in electronics can stay at Gearslutz for all I care. My intention here is to have those drawings posted so that those that are not interested in electronics don't have to ask questions answered by the inscrutable schematic or that require valuable minutes of searching the forum to find the answers to ;D.

Well, I think that's a bad attitude, but it's yours to have if you want. Do you actually make music? If so, and you go to a place like Gearslutz and ask about ways to achieve some sound and someone just posts a link to a song that sounds like that and says if you can't figure it out from that, then maybe making music isn't for you, what kind of attitude would that be?

That's very generous of you to permit me to have my opinion. Thanks for that.

These days I find time to play my bass and piano, but seldom record.

If you are comparing my boards to someone linking to a song, well I disagree with that comparison. In that context someone who has my boards would be like someone having access to the multitrack session with recalls who just has to figure out how to load it into Pro Tools.

90% of the "wiring" has been done with these boards. All that is required is to hook it up to the off-board components and perform the calibrations.

Quote from: Dean Roddey
I didn't ask HOW to do a fuse. I asked WHY doesn't it have a fuse. It's not the same question. You seem to be too busy trying to explain to me why I'm an moron than actually reading the question. And even if I found another thread, it's very difficult to know if the information is up to date with the latest designs, which is one of the big problems with how things are done around here.

I think you will find that many power transformers have a built in thermal fuse and have had them for at least the life of this project.

Quote from: Dean Roddey
Anyway, I will not be bothering you anymore. I'm not coming back because I really don't care to have anything to do with this kind of attitude. So you will not be forced to spend anymore of your time telling me what a moron I am.

What about that drawing you were going to do?
Title: Re: 1176LN Rev D DIY
Post by: fazeka on June 20, 2009, 07:15:55 PM
+1 Skylar, Mike and Mako

The last page or two just confirms my feeling more and more nowadays: more and more people wanting something for nothing. They can't afford the real product so they try to get around it and save a few $$$ and then when trouble hits them and they're too lazy and/or ignorant to figure it out, they expect someone to come in there for free and fix it for them.

My take is that it's cool if someone's willing to offer the help, that's fine. But somehow people expect it, like they're entitled to it (I'm talking about this situation as touched on by Skylar above). That blows me away.

So, like everyone else's opinion, that's mine. If someone has a problem with it, as they say in the old world, "tough sh*tski".
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 20, 2009, 07:18:53 PM
I would like to help but seriously I know less than you.  :-\

I can see that you're passionate about completing your build and getting it working and at the same time, trying to spread a good word about the unit.

I only have pics to offer from what I have gathered but Il try to throw in what I have learnt so far.
Title: Re: 1176LN Rev D DIY
Post by: luis on June 20, 2009, 07:35:54 PM
I found the problem: The R32 that I replaced had cold solder, but was a tricky one! It did not appear to be cold solder at all!
I rarely have cold solder in my small diy´s but we are always learning!

Thank you all for you help.
luis
....

Luis:
I doubt it's damaged. Lots of people have accidentally wired the OT wrong and had R32 flame up (including me!).  

Mike

Well, my compressor passed sound before, the meter moved (when I had the OT correctly wired) and now after burning the  R32 due to ot wired wrong , the sound does not pass neither the meter moves.
I already unsolder all transistors, and will try again with new transistors. My doubts:

- even with the transistores damaged should the sound pass?
Can the wrong OT wiring damage other components beside R32?

Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 07:39:59 PM
I found the problem: The R32 that I replaced had cold solder, but was a tricky one! It did not appear to be cold solder at all!
I rarely have cold solder in my small diy´s but we are always learning!

Thank you all for you help.

Awesome.  I know how rewarding it is to finally find a pesky problem like that.

Happy squishing!

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 08:51:36 PM
Quote
What about that drawing you were going to do?

Yes, I will still do it, though I don't know why I should, given the comments being made by some others here. But I'm willing to do it to help others coming after me.

So it powered up fine, well after the frying of R32 the first time. It would be awfully nice if you'd take a minute and update the incorrect output transformer labels on the board drawing in the PDF file, so that people could avoid this after having covered the board with the molex connectors and wiring it up based on the PDF file.

So anyway, I replaced R32 and figured out the correct output transformer wiring, and it powers up. The only wierdness so far is that the meter lamp doesn't go off when the meter switch is in the first position. The meter reacts as probably expected pre-calibration and goes hard right in position two (GR I assume) and drops back the other direction in position three (output level I assume.) But the meter lamp doesn't go off in position one. I have it strapped across the +/- of the power transformer inputs to the main board with the appropirate 220 2W resistor.

I'm going to go ahead with the calibration, but I'm guessing that the meter not going off is not a particularly good sign. But I'll see how it calibrates. I figured out after the fact what the shorting pads were for. I didn't have any header to go there so I just made my own out of spare legs cut off some larger capacitors in an earlier project. So I should be able to give the calibration a try and see what it does in the meantime.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 08:56:15 PM
+1 Skylar, Mike and Mako

The last page or two just confirms my feeling more and more nowadays: more and more people wanting something for nothing. They can't afford the real product so they try to get around it and save a few $$$ and then when trouble hits them and they're too lazy and/or ignorant to figure it out, they expect someone to come in there for free and fix it for them.

My take is that it's cool if someone's willing to offer the help, that's fine. But somehow people expect it, like they're entitled to it (I'm talking about this situation as touched on by Skylar above). That blows me away.

So, like everyone else's opinion, that's mine. If someone has a problem with it, as they say in the old world, "tough sh*tski".

Well, unlike you guys, I'm GLAD to give people help. And once I know how it works I'll be glad to help people all the time. I do this on the music related fora all the time and put in a lot of time helping other people. You know nothing about me and trying to act like I'm some greedy ***** who just wants to get everything handed to him is ridiculous. I'm an extremely helpful person in those areas where I have the expertise. But this is an area where I need help in this case. I'm perfectly happy to do the footwork to measure things and figure out what's going on, but I cannot figure out how to do those things myself.

And yes, gasp, I'm freaking poor so I have to build things instead of buy them. I mean how sick is that? I should shoot myself or something, obviously.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 09:01:27 PM
So it powered up fine, well after the frying of R32 the first time. It would be awfully nice if you'd take a minute and update the incorrect output transformer labels on the board drawing in the PDF file, so that people could avoid this after having covered the board with the molex connectors and wiring it up based on the PDF file.

It has been updated.

http://www.geocities.com/m_natsume/1176_revision_d

See the top two links?  He has a .pdf for V1 and V2.  Keep in mind some people purchase boards and sit on them for a while so there maybe some people who still need to access the V1 .pdf.

So anyway, I replaced R32 and figured out the correct output transformer wiring, and it powers up. The only wierdness so far is that the meter lamp doesn't go off when the meter switch is in the first position. The meter reacts as probably expected pre-calibration and goes hard right in position two (GR I assume) and drops back the other direction in position three (output level I assume.) But the meter lamp doesn't go off in position one. I have it strapped across the +/- of the power transformer inputs to the main board with the appropirate 220 2W resistor.

I don't know the rotary version very well.  I assume the 3 pos are bypass/GR/+4.  If that is the case it would be right that your lamp stays on in bypass.

Where is the "off" on that rotary or separate?

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 09:04:01 PM
I was told that off is the first position of the meter switch. So I assume there's no bypass, just off, GR, and output level? There's only three positions and one of them is supposed to be off, so that only would leave two others.

Quote
See the top two links?  He has a .pdf for V1 and V2.  Keep in mind some people purchase boards and sit on them for a while so there maybe some people who still need to access the V1 .pdf.

Hmmm... The one I have on my computer has the right info, but the one I printed out much earlier must have been the earlier version or something that still had the incorrect info.

Oh well, that's spilt milk under the bridge now I guess. As long as it's been corrected for those folks smart enough to print out the correct one.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 09:09:33 PM
I really think the 3 pos are bypass/GR/+4 looking at a few complete units online.

Is your toroid primary wired to the meter board?  If you wired the toroid primary directly to your IEC inlet w/ no switch in between you have no off switch.

Sounds like it's working right.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 09:14:47 PM
OK, I guess whoever told me that earlier misunderstood what I was asking. . There are so few folks with pictures of rotary versions to look at as sanity checks that I didn't question that answer. It was back earlier in this thread somewhere.

Oh well, I'll add a power switch to it. But, that's a good thing, since it means it's not hosed (in that way anyway, still plenty of ways to screw the pooch yet I'm sure.)
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 09:18:06 PM
If you want to add a switch (which you don't have too) you would just switch the live on your primary side.  Or your L and N if you want to be safer and have a DPDT switch.

I think you are ready for calibration.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 09:23:59 PM
Oh, so it has to be on the high voltage side? I didn't think about that, but I guess it wouldn't cut off the juice from the wall if you did a DPDT on the other side of the transformer, eh? It's kind of a bummer since it's going to mean running those high AC voltages all the way to the front of the thing and back, across all those wires. That's not a potential hum problem or anything?

Though, I could actually put the switch on the back easily enough. Where it will be in the rack it's easy enough to get to on the back.

So what amperage should the switch handle?
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 20, 2009, 09:28:15 PM
Something rated for 125V/1A or better. 

If you run it to the front you'll want to keep it way from the audio as much as possible.

Here is what I do:
(http://farm4.static.flickr.com/3464/3205487836_14926b7e4e_o.jpg)

Notice how I keep the power switch wires far right (green/black twisted on the right).

Mike
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 09:33:11 PM
I have some spare SP switches from the LA-2A, which are 3A 125V, so they should be plenty. Unfortunately for me there's no way to get the power to the front without crossing way too many audio connections. I didn't account for the need for an audio switch, so all the knobs are well spaced out in a single line along the front panel. So there's no space to put a switch other than slap in the middle of the front panel now.

I'll just it on the back.
Title: Re: 1176LN Rev D DIY
Post by: kazper on June 20, 2009, 09:57:57 PM
Dean,

The factory has been bringing the AC up to the front since S/N: 00000001. Just make sure to twist the wires fairly good along the way. (looks like Mike filled you in)

Because of my I/C background I don't like green used for power period, but because this is DIY it's an non issue. (if it was used)  Be careful twisting the wires on the transformers, they can twist off rendering the transformer useless without repair or replacement depending on damage. Twisting of the power wires and keeping them far away from signals has been discussed before. Best thing to do is study the STA-Level wiring and do like that and you should have no problems in your builds


Also if you must switch one side, take the line voltage (black. hot) as the switched side, but as discussed before it's best to do both.

Kaz
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 10:25:21 PM
Everything is very well twisted or shielded. But it would be awkward from an aesthestic POV to try to wedge a power switch up front now with the way I've spread everything out.

I'll make another run to Fryes right now and get a DPDT switch and do it right. That's only three runs to Fryes today, which is actually not so bad an average for my 'last day of a project' type days.
Title: Re: 1176LN Rev D DIY
Post by: fazeka on June 20, 2009, 11:06:43 PM

Well, unlike you guys, I'm GLAD to give people help. And once I know how it works I'll be glad to help people all the time. I do this on the music related fora all the time and put in a lot of time helping other people. You know nothing about me and trying to act like I'm some greedy ***** who just wants to get everything handed to him is ridiculous. I'm an extremely helpful person in those areas where I have the expertise. But this is an area where I need help in this case. I'm perfectly happy to do the footwork to measure things and figure out what's going on, but I cannot figure out how to do those things myself.

And yes, gasp, I'm freaking poor so I have to build things instead of buy them. I mean how sick is that? I should shoot myself or something, obviously.

Nah, I think you've missed my point and you're not going to get it. That's OK.

It's good to see you're starting to work through the problems on your unit.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 20, 2009, 11:58:22 PM
No, I think I understand all your points. You guys think that electronics knowledge is something worth having in and of itself and you shouldn't build things you don't understand. I have no problem with getting a little electronics knowledge and I have during this process (this is my fifth project, and the last until I can sell a kidney or something to finance some more.) But I have huge intellectual commitments in other areas, and there's only so much I can do. I'll be happy to help some of you if you need some software help, since I suck at a lot of things but that's not one. It's just not worth my digging in deep for something that I'll likely not do again for a long time. I'll have completely forgotten it by the time I need it again and will have to do it all over anyway.

And I will be making what I think will be a huge contribution here in the form of a diagram that anyone like me should be able to use to build the rotary version of this thing without worries. So I'm going to give back in return for some help.

Anyway, I now I have a power switch. I'm going to get my Karma together for a bit here while it warms up and then do the calibration and see what happens.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 21, 2009, 01:14:26 AM
Something rated for 125V/1A or better. 

If you run it to the front you'll want to keep it way from the audio as much as possible.

Here is what I do:
(http://farm4.static.flickr.com/3464/3205487836_14926b7e4e_o.jpg)

Notice how I keep the power switch wires far right (green/black twisted on the right).

Mike
Mike whats that gadget you have in between the Large Input and Output knobs inside your case? It's where the hole on Purusha's case is and I could never figure out what the purpose of the hole and mounts were. I was going to put a led light in there to show that the machine is on or off.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 21, 2009, 01:21:34 AM
That is r71 the 0 adjust.

You can use a PCB mount trimmer, but I like to put a pot on the front panel like an original.  Since the 1176 can drift a little it's nice to have the 0 adjust accessible through the front panel.

I used a 10 turn pot but a single 2K linear would work fine.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 21, 2009, 01:30:38 AM
That is r71 the 0 adjust.

You can use a PCB mount trimmer, but I like to put a pot on the front panel like an original.  Since the 1176 can drift a little it's nice to have the 0 adjust accessible through the front panel.

I used a 10 turn pot but a single 2K linear would work fine.

Mike

My meter drifts based on the voltage coming out of the mains that day.

I never bother to adjust it because it would be a daily or even hourly event. :)

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 21, 2009, 01:37:48 AM
Oy vey... I wired the XLR sockets wrong, i.e. input for output. One of those forest for the trees things. So I'll have to swap those.

While I'm doing that, something I don't get. I was going to start tracing the signal in, to see where it was croaking. I set up a soft synth to generate a 1K sine and patched to my SSL comp and put the meter on in and adjusted the synth output to a steady 0dBVU there, so that I know it's good.

Before I discovered the above snafu, I started trying to measure the signal with my meter. Since I was not getting anything meaningful, I tried measuring them at the actual XLR cable pins on the male end. Shouldn't I be seeing about a 7 volt DC signal between two of the XLR pins? I'm not seeing anything at all.

Oh, and just in case... Do the settings of the other trim pots need to be set to any default setting before doing calibration step one? Or do they not even come into play becasue we've bypassed the GR circuit in this case?
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 21, 2009, 02:42:44 AM
OK, got the XLRs flipped back the right way and I've calibrated up through the two videos successfully and all looks good. I'll poke around for info on the next steps which I guess aren't video'd yet. Then I'll hook it up and try to record a bit.
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 21, 2009, 03:59:49 AM
Quote from: Dean Roddey
I'll poke around for info on the next steps which I guess aren't video'd yet.

Ironically, I had planned to finish the next calibration video with the free time I had this weekend, but instead got pulled into this thread. All of the voice over and most of the video is done, but it still needs to be assembled.

Quote from: Dean Roddey
Shouldn't I be seeing about a 7 volt DC signal between two of the XLR pins? I'm not seeing anything at all.

Can you tell us why you would expect to see 7 Volts DC at either XLR? (I would tell you that DC can't pass through a transformer but I'm sure you don't want to know that).
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 21, 2009, 06:06:00 AM
That is r71 the 0 adjust.

You can use a PCB mount trimmer, but I like to put a pot on the front panel like an original.  Since the 1176 can drift a little it's nice to have the 0 adjust accessible through the front panel.

I used a 10 turn pot but a single 2K linear would work fine.

Mike
Those little PCB mount trimmers for the R71, if I decide to mount them like you have and not use a 10 turn pot, do you know if those trimmers are sensitive to distance? Will it cause problems if I use those little trimmers externally and extend them out with cables liek you have because the pots you are using are expensive?  :(

Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 21, 2009, 02:10:10 PM
Before I discovered the above snafu, I started trying to measure the signal with my meter. Since I was not getting anything meaningful, I tried measuring them at the actual XLR cable pins on the male end. Shouldn't I be seeing about a 7 volt DC signal between two of the XLR pins? I'm not seeing anything at all.

I know that you really don't want to know this stuff and just want the answers. ::)

Audio is AC and if you're talking about the 1khz test signal for alignment it should be 0.775VAC across pins 2 and 3.

http://www.jimprice.com/prosound/db.htm

This is audio engineering 101.

Mark
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 21, 2009, 03:13:50 PM
I meant .7, not 7. That was a typo. I'd been going for like 14 hours on this by then. And yes after I typed that I figured it out myself and did a lot of measuring. I was just kind of thinking out loud more than anything else. But thank you for coming back and being an a$$hole some more. I was really missing that. I swear this is the most pathetic excuse for a community I've ever seen in my fairly long life online.
Title: Re: 1176LN Rev D DIY
Post by: Dean Roddey on June 21, 2009, 03:28:03 PM
Quote
Can you tell us why you would expect to see 7 Volts DC at either XLR? (I would tell you that DC can't pass through a transformer but I'm sure you don't want to know that).

Yes, I figured this out. You know what. Just blow me. I'm sick all of you and your sanctimonious BS. You're a pathetic bunch of losers like I've never seen in my life. I'm really out of here now. I'll get it working myself, else I'll toss in the garbage.
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 21, 2009, 03:30:09 PM
I meant .7, not 7. That was a typo. I'd been going for like 14 hours on this by then. And yes after I typed that I figured it out myself. I was just kind of thinking out loud more than anything else.

Just to refresh your memory

Quote from: Dean Roddey
Shouldn't I be seeing about a 7 volt DC signal between two of the XLR pins?

I'm sure the DC part was a typo too.  ::)

Quote from: Dean Roddey
You know what. Just blow me. I'm sick all of you and your sanctimonious BS. You're a pathetic bunch of losers like I've never seen in my life. I'm really out of here now. I'll get it working myself, else I'll toss in the garbage.

Nothing like biting the hand that feeds.

Mark
Title: Re: 1176LN Rev D DIY
Post by: JoleFIN on June 21, 2009, 03:50:43 PM
:D

Reading the stuff about working on "14 hours straight" and hence being totally stuck with thoughts and getting angry about myself not figuring out something that seems obvious and simple... yes I could relate to that. But I couldn't relate to the last post by Dean.

Marvellous action :D ;D ::)

Title: Re: 1176LN Rev D DIY
Post by: mnats on June 21, 2009, 05:34:32 PM
Quote
Can you tell us why you would expect to see 7 Volts DC at either XLR? (I would tell you that DC can't pass through a transformer but I'm sure you don't want to know that).

Yes, I figured this out. You know what. Just blow me. I'm sick all of you and your sanctimonious BS. You're a pathetic bunch of losers like I've never seen in my life. I'm really out of here now. I'll get it working myself, else I'll toss in the garbage.
It was a simple question Dean. My intention was to find out your reasoning of why you would think there was 7, 0.7 or indeed any DC voltage at the XLRs.

You wouldn't believe the sort of misconceptions I had before discovering this forum and that was after a lifetime of having electronics as one of my hobbies. These misconceptions were part of the impetus to go back to school and study. Now electronic repair is my profession (though sometimes it feels like I'm more of a mechanic, particularly compared to many of the members here). There's always more to learn - in life in general too, I would suggest.

That's part of the reason I'm passionate about being an electronic "evangelist" and why (and I already know you've made it clear that it's a bad attitude) I prefer to provide boards to people who want to learn about electronics and why I don't want to "make a lot of money" doing it. I already have a full-time job that pays the bills and makes it possible for me to spend my free time developing new projects, creating videos etc.

One thing that I've taken on board from this discussion is your point about having an illustration showing the wiring of my boards to the external components. I do think it would cut down considerably on the number of repetitive questions by those who cannot read schematics.

I've asked one of the forum members to consider doing these illustrations for inclusion in my PDFs posted to my site.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 21, 2009, 06:54:19 PM
Dean, do not throw away your unit yet. See if you can get it checked out by an Electronics technician or something. Bring them the schematic and your unit and ask them to quote on finishing it off if you get desperate. If you are not happy with the quote, then sell it if you want. Maybe they can work out the issue with a simple service check and then you can finish it off. I read in a post somewhere where a person did the same thing and got his up and running by a tech.

Also sometimes a nice break can help you see the light of where the issue is on your build. Take a break and then in a few days or a week take another stab at it. Enjoy your La2a and other gadgets you have built for the meantime. Focusing too hard on one thing can sometimes blind you when problem solving or trouble shooting.
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 21, 2009, 08:32:00 PM
Dean, you're probably not going to do yourself any favours by saying that you're sick of us all. It's up to you though, but you'll find in some cases that you'll really need this place I reckon if you want to complete these projects. I don't understand people who say something along the lines of "you don't even know me..." followed up by something like "and I think you are a dicks...". There's irony there.

Regarding measuring AC voltage, your meter probably won't have a good frequency response up to 1KHz. Try 50Hz instead.
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 25, 2009, 04:45:30 PM
For the record, although I've heard that the output transformer wires should follow blue = hot, and red = cold, I have found that the phase is correct if wired the opposite way around.

I'll post some photos of my unit later when I get hold of a camera.

Roddy
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 25, 2009, 05:40:45 PM
Anyone have the wiring info or diagram to Hairballs EA-5002 Output transformer for the 1176 Rev D version 2 or a link to where I can find the information. Skylars diagram is for Cinemag only and there are 3 other wires and shield in Hairball transformer that's not matching to Skylars diagram.

Also the shield on Hairball output transformer, do I connect that to star ground or the case.

Thanks

Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on June 25, 2009, 06:14:03 PM
Anyone have the wiring info or diagram to Hairballs EA-5002 Output transformer for the 1176 Rev D version 2 or a link to where I can find the information. Skylars diagram is for Cinemag only and there are 3 other wires and shield in Hairball transformer that's not matching to Skylars diagram.

Also the shield on Hairball output transformer, do I connect that to star ground or the case.

Thanks



Try having a look at the Rev D schematic, it shows the connections for the output transformer.

Mark
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 25, 2009, 06:29:01 PM
Anyone have the wiring info or diagram to Hairballs EA-5002 Output transformer for the 1176 Rev D version 2 or a link to where I can find the information.

Follow Skylar's latest drawing. Also note rev. 1 and rev. 2 PCBs have different layouts for the headers where the transformer wires attach.

Use the ground wire if you like; I trusted the chassis bond as the chassis is tied to mains earth as part of the star ground.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 25, 2009, 06:50:44 PM
There is a difference between the CM and EA-5002 part.  For the EA-5002 you need to connect the yellow and orange wires together (and to nothing else).  On the CM part this conection is internal.

Mike
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 26, 2009, 10:27:20 PM
Something rated for 125V/1A or better. 

If you run it to the front you'll want to keep it way from the audio as much as possible.

Here is what I do:
(http://farm4.static.flickr.com/3464/3205487836_14926b7e4e_o.jpg)

Notice how I keep the power switch wires far right (green/black twisted on the right).

Mike

Hello Mike!

I already finished my second 1176LN RevD with your hardware! and it's fantastic!! but I have two issues...

The first one is:
The pushbutton's ratio board, isn't shown reversed on the schematic? I thought that I had wired in a wrong way my first one, and carefully wired the remaining one reagarding this topic. I regulated them with no problem, and both are working propertly! but had the same impression in my previous one...
I felt and hear that, in the way you have in the photo above, the gain reducton doesn't match with the labeled... in your schematic that comes with the board/switches, you say that the 1:20 is the pushbutton near the board's wiring contacts...
In fact, using the 1:4 labeled the first bottom position, I just can hear a hard compressing, that I don't in the labeled position 1:20 with the same settings, just switching the pushbuttoms... so, in both 1176 I reversed the board (the wiring contacts went down) and now everything seems to be right and kickin'!

Another issue:
I'm using a attack pot with a SPDT switch, so I'm wiring like you say in your schematic... just a original clone... and I noticed that it just only switch off the compression for the 1:4 and 1:8 ratios... for the 1:12 and 1:20 they still compressing... It's happening in my both 1176... is it the 1176 normal behaviour??

Please let me know, thanks for your amazing work and supplying this wonderful material!

Cheers,

Eddie  ;D
Should I do something wrong? I think I don't... but is just a question
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 26, 2009, 10:49:51 PM
My meter board wiring is correct.  I think you are getting the threshold confused with ratio (which is something you really need to measure).

At most settings if you keep all the knobs in the same place the 1:4 ratio will show more GR on the meter (and to your ears) than the 1:20 ratio setting.  This is because (generally) as the ratio increases the threshold increases.  However, if you plot and measure the the input vs output and examine the GR ratio you will see what you would expect.  

Have a look here:
http://www.axtsystems.com/index.php?view=article&catid=34%3A1176ln&id=54%3A1176lnratios&option=com_content&Itemid=27

As fr the SPDT switch, it sounds like you have a wiring issue.  I would look at it again.

Mike
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 28, 2009, 07:25:52 AM
- Which is + and - on the Mnats altran input transformer pcb board that connects to the "in" of the Main Mnats PC board?
- How do you wire the Hairball Fet Compressor Pot attenuator? Skylar has a different pot for his diagram? Is there a wiring diagram or instructions for wiring the Hairball Fet Compressor pot somewhere?

Hairball Meter Push Button PCB board
- Also, if you use the SPDT switch on the attack pot, how does it change the wiring for the Hairball Meter board and Skylars diagram?
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 28, 2009, 07:33:23 AM
- Which is + and - on the Mnats altran input transformer pcb board that connects to the "in" of the Main Mnats PC board?

See Skylar's rev. 3 drawing.

Quote
- How do you wire the Hairball Fet Compressor Pot attenuator? Skylar has a different pot for his diagram? Is there a wiring diagram or instructions for wiring the Hairball Fet Compressor pot somewhere?

See Matta's attenuator drawing.

Quote
Hairball Meter Push Button PCB board
- Also, if you use the SPDT switch on the attack pot, how does it change the wiring for the Hairball Meter board and Skylars diagram?

Read the section regarding SPDT switch wiring in the Hairball pushbutton guide. Then disregard the switch wiring (pad 22, GRN and BLK) shown on Skylar's drawing as you are switching using a different switch.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 28, 2009, 07:41:22 AM
See Skylar's rev. 3 drawing.
Are you saying J pad 4 side is where - is on the actual Altran PC board? I can't tell how he is facing the board on his pic. I have my boards positioned differently?

See Matta's attenuator drawing.
Whos Matta? Where is this drawing you speak of? Is it a drawing of Hairballs T-pad or the other one with the 2 resistors?

Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 28, 2009, 07:48:50 AM
(http://www.matt-allison.com/diy/1176/1176_attenuator.jpg)
Is this what I follow?
Title: Re: 1176LN Rev D DIY
Post by: Davo on June 28, 2009, 07:54:57 AM
Yup, follow that pic... the hairball attenuators don't need the resistors
Title: Re: 1176LN Rev D DIY
Post by: rodabod on June 28, 2009, 09:03:22 AM
See Skylar's rev. 3 drawing.
Are you saying J pad 4 side is where - is on the actual Altran PC board? I can't tell how he is facing the board on his pic. I have my boards positioned differently?

I don't understand your sentence, but basically, hot goes into Altran PCB pad 2, and comes out of the pad labelled (+). Cold goes into pad 4 and comes out pad (-). Or you can just look at Skylar's drawing and figure it out from their location. It'll only affect phase which you can corrrect with the swap of two wires wherever the signal is balanced. You should check phase when the unit is finished anyway; people here who wired the output transformer with red to cold, and blue to hot probably have the phase reversed.

Roddy
Title: Re: 1176LN Rev D DIY
Post by: mnats on June 28, 2009, 05:16:41 PM
- Which is + and - on the Mnats altran input transformer pcb board that connects to the "in" of the Main Mnats PC board?
Can I ask why you aren't using one of the Altran-only boards that Mike distributes with the input transformers? I designed them specifically to remove any doubt about how to wire the Altran as there are no alternate transformer or H pad options to confuse the builder. The - and + is clearly marked on those boards.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 28, 2009, 09:25:39 PM
- Which is + and - on the Mnats altran input transformer pcb board that connects to the "in" of the Main Mnats PC board?
Can I ask why you aren't using one of the Altran-only boards that Mike distributes with the input transformers? I designed them specifically to remove any doubt about how to wire the Altran as there are no alternate transformer or H pad options to confuse the builder. The - and + is clearly marked on those boards.
I bought the Altran from Mike in a 1176 Full Kit before he started providing the new Transformer boards with the Altran. Where is the + and - on your old boards Mnats?
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 28, 2009, 09:38:44 PM
Hello all,

I'm having some issues calibrating my 1176LN Rev D. I check and double check all the connections and everything seems to be ok. The calibration priocedure I did without problems... and after that putting some audio, it's compressing and the sound is nice and the unit is doing what is suppose.
But I have some questions:
- When I have my attack pot "off" (I use the SPDT switch on the pot) wired like Mike said, and put 0dB (0.775VAc) between Input's XLR pin 2 and 3 (actualy I shunt pin 3 with pin 1, and inject the signal from my function generator in ther pin 2 and the 1+3)... Is normal when I'm in +4 (reading the output), if I switch between the ratios I read different values on the meter??? is it happen on the original? it's not supposed the meter stays still? really don't understand... I realize that when I was trying to make the graphic for the ratio's curve...
I really need some help... it's a strange behaviour I think...

Cheers,

Eddie  ???
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 29, 2009, 04:50:08 AM
Is this correct?
(http://www.ine-kpro.com/diy/1176/images/check/wireCheck1.jpg)

(http://www.ine-kpro.com/diy/1176/images/check/wireCheck2.jpg)
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 08:51:35 AM
(http://i685.photobucket.com/albums/vv213/samplegod/wireCheck3.jpg)

Is this black wire in the middle's pot switch goes to the ratio board too? or am I miss understanding the image?
I thought this wire goes directly to the main board pad 22 only.. is this correct??

Cheers and really thanks for the images!!

Eddie :)
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 29, 2009, 12:14:41 PM
I bought the Altran from Mike in a 1176 Full Kit before he started providing the new Transformer boards with the Altran. Where is the + and - on your old boards Mnats?

I started shipping dedicated input transformer boards in February which was a few months before your order.  You should have received the board in the same bag as your input.  If you did not, that is my error and I would be happy to ship one to you right away.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 29, 2009, 12:27:46 PM
Quote
Is this black wire in the middle's pot switch goes to the ratio board too? or am I miss understanding the image?
I thought this wire goes directly to the main board pad 22 only.. is this correct??

No that common lead/lug should not be going to the ratio board.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 12:38:34 PM
Is this correct?
(http://www.ine-kpro.com/diy/1176/images/check/wireCheck1.jpg)

I'm using Mike's board and follow the +/- indication... have no reversed signal at the output, so I assume that's correct!
Cheers,

Eddie :)
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 02:32:40 PM
Just a question,

The GR mode is "on" when we get the pad 22 connected with the green on the ratio board, isn't it?
Cheers,

Eddie  ???
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on June 29, 2009, 02:54:12 PM
Yes.

When you turn GR off you are shorting pad 22 to ground which is "BLK" on the ratio board.

Mike
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 06:45:39 PM
(http://i685.photobucket.com/albums/vv213/samplegod/wireCheck3.jpg)

So, when the connection that I have on my is wrong... and in this picture is wrong too... because when I switch "on" the pot... it connects the middle lug with the CCW lug (that what's happening in this picture that you have the "black" connection there), and otherwise, with the switch off it connects the middle lug (pad 22) with the CW lug (I'm seeing the pot from the front, from the knob view).

But nevermind, because I tried both ways and the result is equal... and it is supposed not to be that way, in both cases the comp is always compressing, and with the GR off with 0dB signal on the input, with meter in +4 mode (reading output), it changes between switching the ratios... it's not supposed to happen...
I should have some problem on the main board actually, because I check all the connections... and it seems to be OK.

Any Clue??

Cheers,

Eddie :)
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 07:24:58 PM
PROBLEM SOLVED!!!

I think there's a missunderstandig in one thing in your schematic Mike,
In the ratio board you say as "black" the shield from 22 pad, and you're right in saying that! but, in the wiring information you only saying to connect the pad 22 to the pot switch's central lug, that's right, seeing from the front of the pot (knob view) the CCW lug is connected with the "green" pad on the ratio board, and the CW one with the ratio's "black" pad... but in any time your saying that we need to connect the switch's pot CCW lug to ground too! is that needed because is the only way you have to connect the pad 22 to ground... in other words... you need to connect the shield that are coming beside from pad 22 with the CCW lug too.. so when you put the GR off you're shunting the pad 22 to ground... tied that, all the problems gone and the unit now is responsing 100% the way I expected...

I think this is just one smoth question, that makes a large difference :)

Thanks a lot Mike! awesome work, I'm loving your stuff, love the in and out trafos... tomorrow I'll finally compare my unit with the real 1176LN Black Face ;)
I'll post the results!!!

Cheers,

Eddie  ;D
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 29, 2009, 09:56:36 PM

Is this black wire in the middle's pot switch goes to the ratio board too? or am I miss understanding the image?
I thought this wire goes directly to the main board pad 22 only.. is this correct??

Cheers and really thanks for the images!!

Eddie :)
O.K. hopefully this is more clear on exactly what I have done. I am following Skylar diagram and a mixture of what I perceive to be what Hairball was telling me.
(http://www.ine-kpro.com/diy/1176/images/check/wireCheck3.jpg)

Mike, I did not receive the new boards for the Altran Transformer.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 29, 2009, 10:36:15 PM

Is this black wire in the middle's pot switch goes to the ratio board too? or am I miss understanding the image?
I thought this wire goes directly to the main board pad 22 only.. is this correct??

Cheers and really thanks for the images!!

Eddie :)
O.K. hopefully this is more clear on exactly what I have done. I am following Skylar diagram and a mixture of what I perceive to be what Hairball was telling me.
(http://www.ine-kpro.com/diy/1176/images/check/wireCheck3.jpg)

Yes.. that's it!!but I still suggest you to verify with the multimeter, if when the switch turned "off" the pad 22 goes to the ground ("black"), and when it's turned "on" if the pad 22 is connected with ratio's "green" pad.
What I've done was just take the shield I had cutted off from my pad 22's cable, and grab the shield again and attach this shield to the lug where the ratio's "black" are connected... this way I'm sure when I turn off the GR, the pad 22 goes to ground for sure...
My unit now is working propertly in any ways!
Tomorrow I'll compare with the original 1176LN Black Face ;)
I'll post the results!

Cheers!

Eddie ;D
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 30, 2009, 12:02:00 AM
Here is the correction to the wiring. Thanks for telling me to do a continuity check  :)

(http://www.ine-kpro.com/diy/1176/images/check/wireCheck2b.jpg)
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 30, 2009, 12:23:05 AM
Here is the correction to the wiring. Thanks for telling me to do a continuity check  :)

(http://www.ine-kpro.com/diy/1176/images/check/wireCheck2b.jpg)

Swapping the wires is what I did too! but I extract the shield, that I previously cut from the pad 22's wire and reconnected to the lug! It's the same as you did!
How's your unit behavior now? mine is pretty fine!

Cheers,

Eddie  ;D
Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 30, 2009, 12:33:16 AM
Eddie, I am not up to that stage yet. I still have to do my Meter board wiring and XLR output and output Xformer wiring. I added a ground lift to the XLR ins and outs. I am not sure yet whether I will implement the Drips ground lift system using a cap and resistor or just leave it as a dead connection for ground lift on. Anyone implemented ground lift in their 1176 Rev D, if so, what worked for them?
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on June 30, 2009, 12:46:55 AM
Eddie, I am not up to that stage yet. I still have to do my Meter board wiring and XLR output and output Xformer wiring. I added a ground lift to the XLR ins and outs. I am not sure yet whether I will implement the Drips ground lift system using a cap and resistor or just leave it as a dead connection for ground lift on. Anyone implemented ground lift in their 1176 Rev D, if so, what worked for them?

Ok! I implement a ground lift in one of my 1176, but you know what... it is dead quiet both ways... never get problems with noise floor! but is a good idea that Drip's connection... I think you can use that!

one thing I think it was discussed previously in this thread is a stereo link for the Rev D... we can't just add a wire like in the mnta's Rev J... I saw the Purple audio schematic from the MC77 (that is a Rev D class A) and they have a circuit regarding the stereo connection... i think that should be great for improve this project...

MC77 Manual & Schematic Pdf File (http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf)

Just see the last page to view the stereo link schematic.
Any Idea about how to wire that?

Hey Canidoit, when you get yours stuffed and working, please let me know if everything's ok!

Cheers,

Eddie  ;D


Title: Re: 1176LN Rev D DIY
Post by: canidoit on June 30, 2009, 12:54:27 AM
Eddie, I am not up to that stage yet. I still have to do my Meter board wiring and XLR output and output Xformer wiring. I added a ground lift to the XLR ins and outs. I am not sure yet whether I will implement the Drips ground lift system using a cap and resistor or just leave it as a dead connection for ground lift on. Anyone implemented ground lift in their 1176 Rev D, if so, what worked for them?

Ok! I implement a ground lift in one of my 1176, but you know what... it is dead quiet both ways... never get problems with noise floor! but is a good idea that Drip's connection... I think you can use that!

one thing I think it was discussed previously in this thread is a stereo link for the Rev D... we can't just add a wire like in the mnta's Rev J... I saw the Purple audio schematic from the MC77 (that is a Rev D class A) and they have a circuit regarding the stereo connection... i think that should be great for improve this project...

MC77 Manual & Schematic Pdf File (http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf)

Just see the last page to view the stereo link schematic.
Any Idea about how to wire that?

Hey Canidoit, when you get yours stuffed and working, please let me know if everything's ok!

Cheers,

Eddie  ;D



No idea Eddie how to wire that, sorry. :(
It be great if there was a PCB board floating around to add stereo link.  :)
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 02, 2009, 08:17:16 AM
What fuse for the IEC socket? On the UA 1176 re-issue, they use I think a 250 volts 1/16 amp fuse Slo Blo. What is it for the Mnats 1176 Rev D using Hairball Power Transformer for 240 volts?

For those that know the 1176 Mnats Rev D very well, can you please have a look at my visual check thread which I have placed up,
http://www.groupdiy.com/index.php?topic=34385.0 (http://www.groupdiy.com/index.php?topic=34385.0)

Can you spot anything wrong visually with my build.

It would be great  :)

Thanks
Title: Re: 1176LN Rev D DIY
Post by: mac on July 02, 2009, 08:27:32 AM
Hey Canidoit,
Page 92 of the G1176 thread has a quote from Geoff in relation to Dual G1176...

Quote
1 Amp slow-blow should be ample.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 02, 2009, 09:18:43 AM
Any advise before I plug it in and turn it on. Any pre-liminary test procedures I should be aware of and implement before turning it on?
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on July 02, 2009, 09:54:35 AM
What fuse for the IEC socket? On the UA 1176 re-issue, they use I think a 250 volts 1/16 amp fuse Slo Blo. What is it for the Mnats 1176 Rev D using Hairball Power Transformer for 240 volts?

http://www.groupdiy.com/index.php?topic=47.msg420494#msg420494

Mark
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 02, 2009, 10:15:29 AM
What fuse for the IEC socket? On the UA 1176 re-issue, they use I think a 250 volts 1/16 amp fuse Slo Blo. What is it for the Mnats 1176 Rev D using Hairball Power Transformer for 240 volts?

http://www.groupdiy.com/index.php?topic=47.msg420494#msg420494

Mark
Looking at that link:
Assuming, you use a 6VA transformer, divide this VA by your mains voltage, giving 6VA/110V=0.055A. This transformer is maybe only 70% efficient, so multiply the 0.055A by (1/0.7), giving 0.078A. Nearest larger fuse rating will be 100mA. For the larger inrush current of a toroid you want this with slow blow/time lag characteristic. Fuse voltage rating is at least your mains voltage to prevent arcing when this fuse blows, so a 250V/100mA T (=slow blow) might fit for this example. Your transformer may/will be different, so do the math with your values.


Hairball's power transformer specs:
TRANSFORMER, 30VA, 2 X 25V
Voltages, primary:0-115, 0-115
Voltages, secondary:0-25, 0-25
Power, per secondary winding:15VA
Approval Bodies:EN60950, EN60742, UL Recognised
Current rating:0.6A
Diameter, bolt hole:5mm
Diameter, RoHS Compliant: Yes

That would mean Hairballs power transformer is 30VA. So using that method, 30va/240v = 0.125.
0.125 X 1/0.7 = 0.178A

That would mean the closest larger fuse rating would be 200ma fuse at 250 volts that I should install? Have I done this right?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 02, 2009, 02:46:23 PM
Is there a calibration process for the Distortion trimmer R86? I was playing around with it, I want to set it to standard, but I can't find any info on this?
Title: Re: 1176LN Rev D DIY
Post by: gswan on July 02, 2009, 10:55:08 PM
Is there a calibration process for the Distortion trimmer R86? I was playing around with it, I want to set it to standard, but I can't find any info on this?

http://www.groupdiy.com/index.php?topic=34385.msg420877#msg420877

Title: Re: 1176LN Rev D DIY
Post by: fazeka on July 04, 2009, 03:37:58 AM
Hi all,

I am having some difficulty calibrating my 1176 rev. D for 10 dB of limiting. I triple-checked my wiring and can't see anything wrong. I did the Q-bias adjustment and NULL 0.00 VDC pot adjustment.

When I try to set my 10dB swing, I can only get a max of +8.75 dB with the input attenuator full up (full CW). It's funny, my output is barely up (almost full CCW at -46 dB) to get the 0 dB. Not sure if those two are interacting, but I tried turning up the Output to get +10 dB but this throws the swing out of whack and then I have to start over.

Something else I've noticed...

Is it normal for the VU meter to peg when in VU/+4 mode and output at full CCW? I have to turn the Output past -54 dB to get the VU needle back to the left... it's like the Output pot is shorted (?) in the lower range?

(I am using an Alpha output pot, for what it's worth)

Best,
Chris
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 04, 2009, 06:30:02 AM
Hi all,

I am having some difficulty calibrating my 1176 rev. D for 10 dB of limiting. I triple-checked my wiring and can't see anything wrong. I did the Q-bias adjustment and NULL 0.00 VDC pot adjustment.

When I try to set my 10dB swing, I can only get a max of +8.75 dB with the input attenuator full up (full CW). It's funny, my output is barely up (almost full CCW at -46 dB) to get the 0 dB. Not sure if those two are interacting, but I tried turning up the Output to get +10 dB but this throws the swing out of whack and then I have to start over.

Something else I've noticed...

Is it normal for the VU meter to peg when in VU/+4 mode and output at full CCW? I have to turn the Output past -54 dB to get the VU needle back to the left... it's like the Output pot is shorted (?) in the lower range?

(I am using an Alpha output pot, for what it's worth)

Best,
Chris
Are you talking about the calibration in the UREI manual for -10 which is for the R44 trimmer. If so, I had the same problem. I couldn't get gain reduction to meter properly when compressing.

I solved it by putting R44 in circuit(install jumper), leaving the Attack off, Meter on +4 and turned R44 trimmer till I could move the VU needle to 0. If the VU needle wasnt moving or couldnt get the VU needle close to 0, I used a combination of Zero adjustment and R44 trimmer to move the needle to 0. Once the VU needle was set to 0, I put a signal thru the unit, turn attack on and the needle was moving in Gain Reduction finally.
Title: Re: 1176LN Rev D DIY
Post by: rrs on July 10, 2009, 12:21:57 AM
I have a question reguarding setting the Q Bias.

In Mnats video he reffers to placing it closest to ground (In the animated video the link moves on ground side of the pot).

Not sure what is ment by this. Does it meas to adjust the Q bias trim pot to lowest value?  ???
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on July 10, 2009, 01:11:16 AM
I have a question reguarding setting the Q Bias.

In Mnats video he reffers to placing it closest to ground (In the animated video the link moves on ground side of the pot).

Not sure what is ment by this. Does it meas to adjust the Q bias trim pot to lowest value?  ???

That is the starting position for your adjustment.

When you make the adjustment you are turning the wiper away from ground until you get a drop of 1db which is slightly into conduction.

Mike
Title: Re: 1176LN Rev D DIY
Post by: gswan on July 10, 2009, 01:18:32 AM
Actually for a JFET it's the other way around, the closer to 0V Vgs is, the higher the current Ids will be, so the more negative Vgs is the closer to pinchoff (ie no conduction) it gets.
Title: Re: 1176LN Rev D DIY
Post by: rrs on July 10, 2009, 09:38:14 AM
I have a question reguarding setting the Q Bias.

In Mnats video he reffers to placing it closest to ground (In the animated video the link moves on ground side of the pot).

Not sure what is ment by this. Does it meas to adjust the Q bias trim pot to lowest value?  ???

That is the starting position for your adjustment.

When you make the adjustment you are turning the wiper away from ground until you get a drop of 1db which is slightly into conduction.

Mike

Thanks but I'm still no clearer as to how to perform this process. I am gathering I need to adjust the trimpot (R59) to measure 0V somewhere? Maybe at pin 18 ??
Am I on the right track?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on July 10, 2009, 06:34:22 PM
I have a question reguarding setting the Q Bias.

In Mnats video he reffers to placing it closest to ground (In the animated video the link moves on ground side of the pot).

Not sure what is ment by this. Does it meas to adjust the Q bias trim pot to lowest value?  ???

That is the starting position for your adjustment.

When you make the adjustment you are turning the wiper away from ground until you get a drop of 1db which is slightly into conduction.

Mike

Thanks but I'm still no clearer as to how to perform this process. I am gathering I need to adjust the trimpot (R59) to measure 0V somewhere? Maybe at pin 18 ??
Am I on the right track?
David, I thought the voltage measurement was only needed if you are adjusting the null trimmers? You measure the voltage at one of the resistors and set the null and zero trimmers to get zero voltage at the resistor (can't remember which resistor but it's in the video).

As for the q-bias, I just kept on turning it until I was able to see the VU move from what I recall. At the start it wasn't moving because the trimmers were very far off calibration so I kept turning it CW and CCW till I got movement.
Title: Re: 1176LN Rev D DIY
Post by: rrs on July 11, 2009, 05:40:14 AM
Thanks I gathered if I keep turning I will find +1.
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on July 11, 2009, 07:42:08 AM
After Buildt my 3rd 1176LN, I was wondering about a Stereo interconnect... I just looking at to the MC77 schematic, but it's a little bit confuse for me... what they mean as "loop Relay"??
Please see HERE (http://www.purpleaudio.com/pdflib/PurpleMC77v34.pdf) (at page 15)
The sytereo interconnect, as I notice, is NOT like just wiring a wire like in the Rev J! maybe I'm wrong, but I think I'm not  :-\
We should get the 1176SA inbox each unot too, just leaving outside the adjust pot... or if we need to made some extra board to do the stereo link, we could "insert" this little schematic on the board, right?
I love to be able to get my 1176 Rev D stereo connected!
Can anyone help with this?
Cheers,

Eddie :)
Title: Re: 1176LN Rev D DIY
Post by: Grooveteer on July 24, 2009, 05:19:08 AM
EDIT: Problem solved. Ego slightly bruised.  ::) I have wired R71 off-board and wired it incorrectly.
Corrected the wiring and it made life good again.  ;D

Hi guys,

My build seems to have a problem; The Q bias calibration went fine, but when doing the discrete meter calibration I can't get the meter to zero and have 0,00 V on R74 at the same time.  When I adjust R71 the meter goes to the right but no further than say -3 dB. After that it just drops down again. (quickly).   Have already replaced Q12 and Q13 and I have changed R71 to a 5K trimmer.  No luck.

The only way I can get the meter to zero is when I have about 0,7 VDC across R74.  Not good.

I'm using 2N5088 and on my DMM Q12 and Q13 read 507 and 509 HFE, so that should be OK, right?

Any clues? Hints? Tips? Tricks?  ;)

Cheers!
G
Title: Re: 1176LN Rev D DIY
Post by: SaMpLeGoD on July 26, 2009, 12:36:29 AM
Anyone has any clue to stereo interconect two Rev D???
I'll apreciate that!
Thankssss

Eddie :)
Title: Re: 1176LN Rev D DIY
Post by: nielsk on July 31, 2009, 07:15:55 PM
I am finding that I want more "room" on the input att., I wind up having it almost all the way down. Has anyone played with changing the post input transformer (pad?) R4/R5 to stomp down the input level a bit? I do not want to pad before the tranny & change the sound.....
BTW, I built the stereo link as per MC77 on some perfboard and it works very nicely
Title: Re: 1176LN Rev D DIY
Post by: nielsk on August 03, 2009, 03:48:33 PM
Bump.....
anyone?
Title: Re: 1176LN Rev D DIY
Post by: spica on August 06, 2009, 01:41:38 AM
Hi Eddie,

I have had success making my dual Rev. D stereo linked by simply connecting Pad 7 on both channels with a switch.  I matched the fets for both channels together.  If your fets are matched between both channels, you should be in business. 

I just ran through some tests and both channels compress together very well when they are linked.  Even with different levels of input and different gain settings on my 1176's, I'm seeing both channels compress the same amount when one side is triggered. 

Hi Niels,

I haven't had too much issue with sending in too hot of a signal.  If I'm sending full program material, I'll usually lower the ProTools output a bit if I need. 

-Tony
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on August 06, 2009, 02:00:43 AM
Ditto! But most people will tell ya that the link is too loose for a stereo match. That is false! Makes an awesome drum buss. Used by tons of famous engineers. And Also used on the 2 buss. For bigtime albums. Same as la2a. Too dirty? Try it.

What sounds good IS GOOD.

John
Title: Re: 1176LN Rev D DIY
Post by: nielsk on August 14, 2009, 01:58:00 PM
I would like to try getting a slower attack time, would increasing C27 add more time? It seems like it would still be just as fast with the cap/resistor dialed all the way out, but could go slower....
Title: Re: 1176LN Rev D DIY
Post by: LikeLeonardo on August 26, 2009, 06:39:29 PM
I have finished building the 1176LN D ver 2 and am looking for calibration information.  The two videos are great and there are still more things to adjust. The manual I have talks about pots that are not in  my circuit.
Does anyone know where I can get complete info on calibration.
Thanks Nathaniel
Title: Re: 1176LN Rev D DIY
Post by: danjpiscina on September 05, 2009, 12:25:34 AM
That is the voltage dropping resistor for the VU lamp.

The secondary is wired with a center tap (0V).  The voltage between either side of the secondary and the center tap is 25V.  So set your DMM to AC and put your + on either the right or left terminal, then your - on the center terminal and you should get roughly 25V.

Your lamp likes 11V and it doesn't care if it's AC or DC.  Here's where Ohm's Law (V = IR) drops by to help us.

We need to drop the voltage by 14V.  I know my VU is drawing about 0.063A.

R=14/0.063A
R= 222R

There is really no need to guess.

Edit:

Also, if P=V*A, then in this case we've got about 1W of power.  A 2W resistor should do.

Mike

Hi guys. Just a heads up on the VU lamp powering. I tried a 222R with Mike's meter and although it was way too bright, it worked... for a couple of hours but the lamp fried. I put a second 222R in series and it's now more like it should be. Not too bright, not too dark, just right for the studio vibe!
Title: Re: 1176LN Rev D DIY
Post by: pietro_moog on September 10, 2009, 11:19:38 AM
hi everyone!
i'm a noob and i could use some help.

1) i see many of you have 2 big resistors soldered to a pin of the meter, are these 8.2k 1W resistors?

2) some of you have a very big resistor on the toroid connections. do i need it?
   (or your just using a bigger voltage toroid?)

3) this is stupid, but it's very important to me.
    i need mouser codes for 3 pin thing and the clap thing that connect 2 of them, the thing you should remove for fine tuning the circuit.
    i don't know their names, and i'm not so clever in orders
 
thanks everyone
Title: Re: 1176LN Rev D DIY
Post by: regularjohn on September 10, 2009, 12:30:20 PM
The resistors for the meters are 220R/2W.  You put it in series with ONE of the transformer secondaries and that goes to one of the meter pins, and the other meter pin connects to ground.  
Since the power for the meter is coming directly from the power transformer, you can put the resistor near the meter or near the pcb (where the transformer secondary is connected - this might be what you're seeing).  I haven't heard of anyone using resistors to drop down the voltage of their power transformers.  Seems silly to buy a more powerful trafo than you need because it'll cost you more.
Title: Re: 1176LN Rev D DIY
Post by: pietro_moog on September 11, 2009, 08:51:43 AM
thanks, i think i should read the whole tread next time
i'm sorry
Title: Re: 1176LN Rev D DIY
Post by: danjpiscina on September 12, 2009, 02:59:28 AM
Ditto! But most people will tell ya that the link is too loose for a stereo match. That is false! Makes an awesome drum buss. Used by tons of famous engineers. And Also used on the 2 buss. For bigtime albums. Same as la2a. Too dirty? Try it.

What sounds good IS GOOD.

John

I love 1176's on the buss! Who said it's dirty?
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on September 16, 2009, 05:21:53 PM
hello guys
I need help, I can not find R12-920 I can use a resistor 930 without problems?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on September 16, 2009, 05:45:33 PM
hello guys
I need help, I can not find R12-920 I can use a resistor 930 without problems?
Thanks

Definitely.
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 16, 2009, 07:14:18 PM
thanks, i think i should read the whole tread next time
i'm sorry

I have an excell BOM list with web links to part numbers that I made for my Rev D build that you might find useful. Message me with your email address if you would like a copy.

I have built it so that you can print it out and use it to mark your progress as you build the unit or order parts. You can also modify it to suit your needs.
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on September 16, 2009, 07:58:41 PM
thanks Echo North

hello canidoit
[email protected]
thanks
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 16, 2009, 09:30:32 PM
thanks Echo North

hello canidoit
[email protected]
thanks
O.K. sent it  :)

I have also included some other things you may find useful.

Good luck with the build!
Title: Re: 1176LN Rev D DIY
Post by: pietro_moog on September 17, 2009, 07:04:20 AM
thanks canidoit, this is very kind
that's my email
[email protected]
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 17, 2009, 08:19:21 AM
thanks Echo North

hello canidoit
[email protected]
thanks
Antonio, the list you have does not have the attack pot with the switch built in.

Download this version of the part list if you want the attack pot with the SPDT switch. Please check with other information you have to make sure the list meets your requirements. Download and use the information at your own risk!

Exel BOM List (http://www.ine-kpro.com/diy/1176/1176lnRevD-BOM200609v3.doc)
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on September 18, 2009, 06:39:19 AM
Thanks canidoit ;)
Grazie
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 19, 2009, 02:27:40 PM
Hi guys

I'd like to start off thanking all involved for offering boards/kits/parts/info/their time & help on these threads for such a cool DIY project!  ;D

I'm in the process of gathering my parts for this build & have some questions...

I see some builds using a mix of carbon film & metal film resistors. Are there preferred spots for these affecting the tone?

I'm buying a kit from HB with the matched FETS but see that you need to match other transistors.
How do you match these?

Does anyone have the mouser part number for the 3 pin norm short thingie??

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on September 19, 2009, 04:04:27 PM
If ya want to match the transistors you need a meter that measures hfe. Even radio shack sells one... If ya buy 20 transistors at once you will definitely pair a few. But I suggest getting 50 because they are cheap and this won't be the only 1176 you build LOL!

I would use all metal film resistors. They are reliable and sound great. If they have much effect at all. I used mostly carbons on my rev A compressor just for nostalgia.

John
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 19, 2009, 10:33:15 PM
Is it a big deal if you don't match them??

Cheers
Sean
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 20, 2009, 12:17:58 AM
Is it a big deal if you don't match them??

Cheers
Sean
I think matching relates to like 1-2% or is it 5% tollerance? Not sure, but matching the transistors has got something to do with getting the unit to callibrate properly or run correctly from what I have been told. eg. If one of your transistors HFE read 250, then 5% of that is 12.5, so that means you can get another transistor that reads in the range of 237.5 to 262.5 HFE and it would be classified as adequately matched with the 250 hfe transistor. The closer the better though.

Someone please confirm if this is right. To be safe, I would just match them exactly if I can.  :)
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on September 27, 2009, 10:43:57 PM
demand
I just finished 2 Rev D
instead of -10 = -9.3
instead of 30 = 29.3
normal?
may create problems?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: mac on September 28, 2009, 12:48:42 AM
Hey ilfungo,
may be worthwhile to stick a meter into your mains at different times of the day to check what voltage is going into your unit. I used trimmer resistors to set my -10 and +30... and reset them three times before I realised that it was my mains supply fluctuating slightly...

Mac.
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on September 28, 2009, 08:35:49 AM
   
Thanks Mac
I try to do the test ...
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 30, 2009, 01:12:49 AM
Does anyone have the mouser part number for the 3 pin norm short thingie??

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 30, 2009, 02:05:06 AM
Does anyone have the mouser part number for the 3 pin norm short thingie??

Thanks
Sean
Sean, download my exel sheet and it should have the part number link for it. It has the reference for the part on the board and then the part and then a direct link to the website part supplier that you click on. Also has the price of the component at the time when I listed them.
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 30, 2009, 11:54:30 AM
Hmm, can't seem to find it on your list.

Cheers
Sean
 
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 30, 2009, 02:28:00 PM
Hmm, can't seem to find it on your list.

Cheers
Sean
 
Hmm, I don't think that is possible, the list is of all the components that I know of for the Rev D? Where abouts on the PCB is this part you mention of?
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 30, 2009, 02:49:55 PM
In the GR Meter Driver section between R44 & R69. It says "norm short"

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on September 30, 2009, 03:18:20 PM
Canidoit, how come the transistors on the board are 2N3707 & yours & Nimbleswitch's list say 2N3708?

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: phatmateo on September 30, 2009, 05:00:35 PM
because a vast majority of the 3707's dont have a high enough Hfe.  3708's are a good substitution.  All of this is searchable in the forums
Title: Re: 1176LN Rev D DIY
Post by: canidoit on September 30, 2009, 08:50:16 PM
In the GR Meter Driver section between R44 & R69. It says "norm short"

Thanks
Sean
Sean, thats called (x amount of pin) Pin Header Terminal Strip. You are right, I think it is not in the list. Sorry  :(. They use that so you can short connections or not. You use this little connection thing that is used for hard drives to make the settings master or slave on the hard drive. Get that part from a computer store or general electronics store or if you have an old hard drive that has a spare one it's not using.

(http://www.jaycar.com.au/products_uploaded/productLarge_7558.jpg)

Here is a link to what you are talking about, its a 28 pin version which you cut to how many pins you want. On the Rev D it uses 3 pins, so you chop that amount. This allows you to short or not that section for calibrating on the R44 trimmer pot. I think what it does, is either makes the R44 trimmer pot in circuit or not. When calibrating, the R44 is not meant to be in circuit, but once you have calibrated the unit, you put the R44 back in circuit by using the little hard drive connector thing. Something like that. This makes it easier to calibrate than having to desolder and re-solder R44 for calibrating. You can get this part in Australia in general electronic stores, so it should be the same for the country you are from as well.
http://www.jaycar.com.au/productView.asp?ID=HM3211&keywords=terminal&form=KEYWORD

Here is a pic of what you are talking about on my build from what I understand. See the little white plastic thing, which is what I got from my computer to make the setting of the R44 in circuit or not. I have it not shorted on the pic, and it is actually hanging off the last pin.
(http://www.ine-kpro.com/diy/1176/images/check/1176check2.jpg)

If you are from Australia, I will send you some for your build, just pay for postage.
Title: Re: 1176LN Rev D DIY
Post by: Skylar on September 30, 2009, 11:00:33 PM
Does anyone have the mouser part number for the 3 pin norm short thingie??

Thanks
Sean


Your question has been answered in this very thread.
Here's a tip for searching long threads like this one.
Hit the "Print" button in the upper right.
(http://i73.photobucket.com/albums/i222/skylargray/Other/gdiy_print_thread.gif)
This opens the entire thread in one continuous page.
Now use your browser's search function (Ctrl+F / Apple+F) to find what you're looking for.

Using the above questions as an example, search for "3 pin"
The first result you find is pantsonfire asking for the Mouser part number for the same part.
The very next post is a reply containing the part number for the terminal and jumper.
(http://i73.photobucket.com/albums/i222/skylargray/Other/gdiy_search_1176D_3pin.gif)

I have found that if you ask a question around here, and you don't get a reply it's not that no one knows the answer...it's probably just that the question has been answered several times before.
I don't mean any offense...just trying to help.
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on October 01, 2009, 01:31:42 PM
Thanks guys for your answers!  ;D

Skylar awesome tip about hitting print for these long threads. Will come in handy fersure!

Cheers
Sean
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 03, 2009, 09:31:24 AM
 ???
Hi guys I have a problem that I can solve ninth
I have 29.2 instead of 30
 -8.9 instead of -10
If I connect the ratio  board -7.6 ???
Can you help me?


across the torroidal I have 28 -0-28...
Thanks
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 05, 2009, 09:26:10 AM
Hi guys
I just finished the first rev D but I have problems ...
When I bring the output to zero the meter goes crazy and goes to full scale (+3)
if unlink xlr out everything returns to normal

could be the connections of 5002?
brown
white black
White Red
grey
violet

and then still have
-8 Instead of -10
29.2 instead of 30 ??? ??? ???
Title: Re: 1176LN Rev D DIY
Post by: bodega on October 06, 2009, 10:37:25 AM
Hi guys,

Quick question about the PSU section: Can I substitute the same tantalum cap that goes in C19 and C20 (Kemet 50v, 6.8 uF, 80-T350F685K035AT on Mouser) for C23, which is supposed to be an electrolytic 6.8uF, 35v?

According to the tantalum wiki, they're frequently used in PSUs, but I figured I should check.

thanks!
Matthew

edit: I had to order some stuff from Mouser anyways, so I'll just go with an electrolytic.
Title: Re: 1176LN Rev D DIY
Post by: Kamel on October 06, 2009, 01:03:29 PM
one more (in fact two), rev D is born, nothing special about the case ( tat's case), but i try to be meticulous for the wiring, many many thanks to Mnats, the board is just perfect to understand the different stage and so clear to solder component, ed anderson for the recreation of the transformers, hairball for the easy to get hard to find component, skylar for his wiring sketch, and of course jakob, as always

http://jardinprive.free.fr/image/1176/1176-01.jpg
http://jardinprive.free.fr/image/1176/1176-02.jpg
http://jardinprive.free.fr/image/1176/1176-03.jpg
http://jardinprive.free.fr/image/1176/1176-04.jpg
http://jardinprive.free.fr/image/1176/1176-05.jpg
http://jardinprive.free.fr/image/1176/1176-06.jpg
http://jardinprive.free.fr/image/1176/1176-07.jpg
http://jardinprive.free.fr/image/1176/1176-08.jpg
http://jardinprive.free.fr/image/1176/1176-09.jpg
http://jardinprive.free.fr/image/1176/1176-10.jpg
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 06, 2009, 02:24:12 PM
Kamel compliments great job!
you could tell me how you connected SPDT?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: Kamel on October 06, 2009, 02:31:58 PM
thank you

if it's the one to switch off compression

22 from board to common on spdt,
off position contact (check it with ohmmeter) gnd from the ground board, near 22
on position contact, to ratio board attack pot (GRN)
Title: Re: 1176LN Rev D DIY
Post by: canidoit on October 06, 2009, 07:56:32 PM
Camel compliments great job!
you could tell me how you connected SPDT?
Thanks
(http://www.ine-kpro.com/diy/1176/images/check/wireCheck3.jpg)
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 06, 2009, 09:03:20 PM
Thanks Kamel and Canidoit
now everything seems to work well! Tomorrow I will test
thanks again ;D

The only problem I have is one of the two compressors, if I put the output  pot CCW  the meter go
to +3 (if disconnected XLR output returns to zero).
you know what can be?
Title: Re: 1176LN Rev D DIY
Post by: Kamel on October 07, 2009, 01:24:11 AM
Quote
The only problem I have is one of the two compressors, if I put the output  pot CCW  the meter go
to +3 (if disconnected XLR output returns to zero).
you know what can be?

check your transformer wiring and calibrate the comp, it may be an issue
Title: Re: 1176LN Rev D DIY
Post by: muffy1975 on October 07, 2009, 06:31:00 AM
Team,

can I use 1n4003 in the PSU section of the Rev A and D? Or must I use 1n4004?

I have loads of 1n4003!!!!! Will it make a difference?

Thanks in advance

Michael :)
Title: Re: 1176LN Rev D DIY
Post by: benidubber on October 07, 2009, 07:40:05 PM
Hi to everyone,
 i can't understand what's going on with the last 1176 rev D i made.
 it works almost as it should but there is a bad distortion increasing with the gain reduction JUST on low frequencies. i mean, the more it compress low freq the more distortion appears. in bypass mode everything's ok and there is NO distortion if i get out the FET in GR mode as well. i changed a lot of 2N5457,checked for dry soldered pins,checked the values with another board which is properly working,   calibrated hundred times but it's still just a nice bass guitar fuzzbox. i made another unit and that is perfect. if somebody knows....let me know!  thanks a lot, bye!!   sandro
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 08, 2009, 02:33:16 PM
I just finished 2 Rev. D ;D
they sounds fine and the stereo connection works ...
I want to say thank Mnats, Echo North, Mac, Canidoit, Kamel and this wonderful forum, without you I could never ...
GRAZIE!!!!!!!

I'll put the photos as soon as possible
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 09, 2009, 04:27:40 PM
my rev A & D
thanks

Sorry, the problem that I said I still have it on one rev D (pot ccw out everything - meter planted in full scale) and I noticed that happens when warm and cold are reversed pole ( XLR out)
I rechecked all the wiring and everything is fine??
What can it be?
THANKS!


it's normal that rev A have more output of rev D with the same transformer (in&out)?
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 12, 2009, 06:39:36 PM
Thanks Kamel and Canidoit
now everything seems to work well! Tomorrow I will test
thanks again ;D

The only problem I have is one of the two compressors, if I put the output  pot CCW  the meter go
to +3 (if disconnected XLR output returns to zero).
you know what can be?



Hi guys
some of you have had a similar problem?
I ask you to help because I rechecked all connections and do not know what else to do  ???
Title: Re: 1176LN Rev D DIY
Post by: cwalcott on October 13, 2009, 02:31:33 PM
greetings,  this is my first post to this thread.  i've avoided it because i have a friend helping me and because it's a little intimating here.  i have searched the boards for an answer to my question and i'm not finding anything definitive.  sorry in advance if i missed anything.

i have a question about the output transformer wiring to the board.  i'm using the complete hairball kit for this build.  i mistakenly wired my board according to this configuration:
http://cedub.com/pub/1176/SG-1176-RevD-OUTPUT-Wiring.jpg
the colors listed on this diagram do not match up at all with what is printed on the PCB - that is, the order is wrong.  it's my bad for not double checking this.  i'm using terminal blocks so the silk screen was covered up.  still, i did have a print out so again, my bad.

when powered it up, i fried R32.  i have a second board all stuffed and ready to go so i'd like to try that one out with the correct wiring.

my question is this.  are the labels on the PCB correct for use with the hairball output transformer?  my PCB is labeled "v2.2 26.01.09".  the board shown in the "v2 building" document on mnats Rev D page is dated 30.04.08. 

Thank you in advance for any advice.

- chris
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on October 13, 2009, 02:35:42 PM
Sounds like you have V2.

http://mnats.net/files/DIY1176LNREVD_V2.pdf

You'll have blue, red, orange and yellow left over.  Orange and yellow get tied together and red and blue go to the xlr out.

Oh and replace R32.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: cwalcott on October 13, 2009, 02:53:20 PM
Quote
Orange and yellow get tied together

thanks mike!  by tied together, do you mean connected together or just clipped?

- chris
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on October 13, 2009, 03:11:04 PM
Yes just tie them together.

If you look at the original schematic, you will see by connecting them you are wiring two of the secondary windings in series.

Mike
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on October 14, 2009, 08:55:15 AM
Hi guys
what type of pot can be used for zero adjustment from the front panel?
I found a potentiometer wire to 2 K multiturn,  can fit?
thanks
Title: Re: 1176LN Rev D DIY
Post by: bodega on October 23, 2009, 02:18:12 PM
check your transformer wiring and calibrate the comp, it may be an issue

I was just looking at the pic of your completed unit and noticed that the label on the Altran is pointing the opposite way as mine. The label on mine is pointing towards the H-Pad links.

I put mine the way it is because that way the dot on the label lined up with the "Altran 1" arrow - was yours on the opposite side?

My pcb is the 07/04/07 edition.

Perhaps I've just put it in backwards - I haven't soldered that in, so now is a good time to make that kind of mistake.
Title: Re: 1176LN Rev D DIY
Post by: Kamel on October 23, 2009, 03:26:45 PM
i don't use the mnat's transformer pcb, but the hairball audio one and on the mnat pcb , the dot (pin one) is near the Hpad option
Title: Re: 1176LN Rev D DIY
Post by: bodega on October 24, 2009, 02:42:34 PM
Ah, that explains it. Ça va, merci!
Title: Re: 1176LN Rev D DIY
Post by: muffy1975 on October 28, 2009, 07:46:57 AM
Team REV D ;D,

What is the effect of having 22k instead of 25k on the attack potentiometer?
What is the effect of having 220K instead of 250k on the output potentiometer?

has anyone got a few of those 25k linear SPDT pots for sale in England/Europe/UK? Or can order a few more if they are putting in an order and sell them on to me?

What is the fastest someone has put one of these REV D's together ( saying you have a precut 2u case ) ? :D

PACE

Michael

XOX

Title: Re: 1176LN Rev D DIY
Post by: dmp on October 28, 2009, 01:11:30 PM
Anyplace I can buy a faceplate?
Do folks build faceplates?
Title: Re: 1176LN Rev D DIY
Post by: RedNoise on October 28, 2009, 02:56:12 PM
Try to check echonorth , hairball shop ...
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on November 02, 2009, 04:36:10 PM
Changing the pot values slightly like you suggest Muffy will be no problem. But changing the input tpad will certainly cause problems. Best to get the t-pad from hairball if you want it to work correctly. I didn't use the switched attack on any of mine. I just wired it to the off pushbutton. So I didn't run AC to the faceplate cause I am paranoid... But I gave my friend a switched attack pot and is working great for him.

John
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on November 12, 2009, 09:09:23 AM
hello
it is normal that the compressors have a lot 'of noise (shhhhhh)?
the problem may be that I connected to a tac scorpion  inserts unbalanced?
sorry for my english....
Title: Re: 1176LN Rev D DIY
Post by: bdubya on November 12, 2009, 05:56:03 PM
Yeah, I get that if i feed it an unbalanced input.  It amplifies the open pin 3 (ssshhhhhhh) along with the hot pin 2.  Use it on a balanced buss, instead?  It should be quiet as a mouse when it gets a balanced signal, though, or somethings up  . . .

bw
Title: Re: 1176LN Rev D DIY
Post by: canidoit on November 13, 2009, 05:58:40 AM
hello
it is normal that the compressors have a lot 'of noise (shhhhhh)?
the problem may be that I connected to a tac scorpion  inserts unbalanced?
sorry for my english....
The Rev D is pretty quiet from my experience. I am using balance XLR connections. People here have commented on how quiet this build is on theirs.
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on November 13, 2009, 12:28:25 PM
my problem is that the Tac Scorpion inserts unbalanced ..

another question

I must  measure the voltage -10
with all the controls connected (ratio board, meter board)?
whether the measure before connecting everything -9.5
If you measure with everything connected -8.6
correct?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on November 19, 2009, 12:02:38 PM
I have solved a problem
I have changed r81 1K with 560 R and the negative tension is now ok
can this create a problem?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: spacecho on November 21, 2009, 12:11:47 AM
Hello Guys!

Im building a pair of these and using the mnats power supply board - i noticed that the wonderful boards mako made (12.05.08) have a marking for +30 at the left side of where R87 (1.1k 1 watt resistor) would go, and -10 at the right side of where CR6 (in4740 diode) would go.

I'm assuming these points are where i would send the +30 and -10.
I want to use the terminal blocks at the edge of the board (where power would normally be routed from the torrodial transformer)

My question is: do i jumper from the base of where CR7 and CR8 / CR10 would be? to the respective voltages points mentioned earlier?
as far as i can tell from the schematic and looking at the pcb (black is hard to see) these pads on the pcb would be a direct link to the power transformer and not connected to anything else (as long as the onboard power parts are ommited) so it should be ok?

Sorry if i'm not explaining this well - i've read through the entire thread and didnt see a mention of this - mako's site has a picture of a rev G board with jumpers on it - bet they are in different places and i thought it better to ask,

Title: Re: 1176LN Rev D DIY
Post by: muffy1975 on November 24, 2009, 11:05:52 AM
Spaceho,

you have the right idea. +30 needs to see +30 and -10 needs to see -10V.

Use a continuity function on your multi meter to connect the header points on the circuit board to the +30 and -10 destinations. Most people use a cut to size piece of wire or the leg of a resistor.

Muffy
Title: Re: 1176LN Rev D DIY
Post by: bdubya on November 24, 2009, 01:00:49 PM
nevermind, I thought you were using the onboard P.S. . . .
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on November 27, 2009, 03:00:31 AM
I'm at the same point but using the main boards PS. Just got the Power Supply parts stuffed & want to check & make sure all things are go before continuing. I'm curious if I need to ground the board?? After stuffing all the parts in the PS block, I don't thing the board itself is grounded yet.

Also do I just use one set of wires on the primary side for 115V? (Canada)
Then tape up the other two?

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: bdubya on November 27, 2009, 10:38:05 AM
The ground occurs through the center tap connection on the edge of the board where you're connecting your AC off the power transformer.  Look back through the thread, and on mnats' page, there's a diagram for wiring up the primary properly for 115V. 

bw
Title: Re: 1176LN Rev D DIY
Post by: williamjf77 on November 27, 2009, 09:49:19 PM
hello im new to this forum but im in a bind this may sound dumb but i have mnats rev f board ind can't find where to wire the input pot?
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on November 30, 2009, 09:12:40 PM
I'm a little confused about how folks are wiring the input XLR these days. Mnats wiring guide is using a different board & no T-Attenuator. I understand where the + & - wires go from the XLR to the T-Attenuator then Input trannie & finally the board but how do I run the shielding?? I have the latest main board from Mnats & the latest Input transformer board from Hairball. Also the latest T-Pad from Hairball. Do I just connect the ground pin on the XLR to the case then run a connected shield to the T-Pad/Input transformer/main board & leave it unconnected along the way??

Thanks
Sean

Title: Re: 1176LN Rev D DIY
Post by: Moolason on December 01, 2009, 11:59:34 AM
That looks very nice,It's a work of art!!!  :)
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on December 02, 2009, 08:30:03 PM
Ciao
I have made 2 REV D and
sounds very nice!!!
It's possible to make another REV d - OEP input and output ?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on December 04, 2009, 09:23:02 AM
Just fired up my build last night & it worked right off the bat! Woohoo!!
Sounds awesome & is compressing wonderfully. I also did the two Mnats video calibrations without problems.

I have a couple minor issues I'm trying to track down, maybe someone can help?

My Ratio buttons are reversed. I get 4:1 when 20:1 is pressed & 20:1 when 4:1 is pressed.
I wired the Ratio board up the way it says in my Hairball kit instructions. I've triple checked & all "looks" well but obviously I'm missing something.  :-\

Also I have the SPDT attack switch & wired it up the way the Hairball kit says to. I see in other posts & diagrams they use the a shielded wire & connect into it but there is no mention of this in Hairballs instructions. I'm not sure if Hairballs Ratio board eliminates the need for this or what but I'm not connecting into the ground pad beside 22. The switch cuts off compression but the meter still shows it.

Any thoughts?

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 04, 2009, 10:33:56 AM
Just fired up my build last night & it worked right off the bat! Woohoo!!
Sounds awesome & is compressing wonderfully. I also did the two Mnats video calibrations without problems.

I have a couple minor issues I'm trying to track down, maybe someone can help?

My Ratio buttons are reversed. I get 4:1 when 20:1 is pressed & 20:1 when 4:1 is pressed.
I wired the Ratio board up the way it says in my Hairball kit instructions. I've triple checked & all "looks" well but obviously I'm missing something.  :-\

Also I have the SPDT attack switch & wired it up the way the Hairball kit says to. I see in other posts & diagrams they use the a shielded wire & connect into it but there is no mention of this in Hairballs instructions. I'm not sure if Hairballs Ratio board eliminates the need for this or what but I'm not connecting into the ground pad beside 22. The switch cuts off compression but the meter still shows it.

Any thoughts?

Thanks
Sean


Your ratio's are probably correct.

The 4:1 ratio has a lower threshold then the 20:1 ratio.  As you increase the ratio (4 to 8 to 12 to 20) your threshold gets higher, which means with the same signal you will see less and less compression on your meter as you move from 4 to 20.  

Looking at the meter is a little misleading.  Check out gswan's explanation of ratio and how to measure it here:
http://www.axtsystems.com/index.php?option=com_content&view=article&id=54:1176lnratios&catid=34:1176ln&Itemid=62

The shield you are seeing on the switch is the signal ground connection.  The bypass switch disables GR when pad 22 is shorted (connected) to ground.  You can get the ground from a shield connected to ground or anything connected to ground.  When pad 22 is shorted to ground you should not see compression on your meter.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on December 04, 2009, 02:07:38 PM
Thanks Mike got the switch taken care of & that makes sense about the Ratio's!  ;D

I've got another concern but maybe it's just the nature of the beast...
The cable running from the output pot to the board (pad 16/15/17) is a bit microphonic.
Is this normal? I know with tube amps there are areas in the circuit like this. It's not
causing any issues that I'm aware of (yet) but when I tap or handle this cable you
can hear it. I just cut & redid the ends but it's still happening. It goes away when
the output pot is at about 3/4 to max but before that you can hear it.

Also... is it normal for the meter to be pinned to the right in slam mode?
It shows reduction with the signal but zeros fully right.

Cheers
Sean
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on December 04, 2009, 03:07:17 PM
I've got another concern but maybe it's just the nature of the beast...
The cable running from the output pot to the board (pad 16/15/17) is a bit microphonic.
Is this normal? I know with tube amps there are areas in the circuit like this. It's not
causing any issues that I'm aware of (yet) but when I tap or handle this cable you
can hear it. I just cut & redid the ends but it's still happening. It goes away when
the output pot is at about 3/4 to max but before that you can hear it.

That doesn't seem right to me but I really don't know.  I'd have to check on mine.

Also... is it normal for the meter to be pinned to the right in slam mode?
It shows reduction with the signal but zeros fully right.

Yes that is right and functioning correctly.

Mike
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 06, 2009, 01:34:26 AM
Nothing should be "Microphonic" in this. Maybe a bad solder joint?

John
Title: Re: 1176LN Rev D DIY
Post by: mnats on December 06, 2009, 06:13:17 AM
Finally managed to finish the third calibration video (scroll down) (http://mnats.net/1176_revision_d.html#videos).
Title: Re: 1176LN Rev D DIY
Post by: bdubya on December 06, 2009, 11:13:56 AM
Thanks alot for doing that.  And such a smooth, sonorous narrator!   ;D

i fumbled my way through the calibration the first time and got it going; this'll make a nice reference the next time around.

Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on December 06, 2009, 02:00:10 PM
OK this calibration has me stumped...
I've done the first two with no issues but I can't get past the first step on this one.
I end up with my input all the way down & output all the way up never attaining the difference.

When I start with both in/out at noon I adjust the out for 0db with the +4 button pressed & GR switched off.
This puts the knob at about 48. (8:00) I turn on the GR & the meter drops to about -8.5. I drop the input dial to 36 (9:30) to attain -10. Now here's where it gets weird... I switch GR of & it's still sitting at -10. I move the output to bring it back up to 0, switch the GR on & it stays at 0. So I keep doing this until I run out of dial space.

Any suggestions?
Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 06, 2009, 05:40:49 PM
I haven't done any calibrations recently. But will soon. Maybe I can help you then.

I have been too busy for projects lately. Everyone always shows completed projects so I figured I would show mine "In progress". I have 4 days off and working like crazy to complete it. Wish me luck.

And thanks again Mako and Ed and Mike at hairball.

I used the flying saucer heatsinks on the output transistors and a bigger heat sink on the regulator. Neither are nessessary but I thought it looked cool. It powers up fine with no explosions or smoke. Just gotta get my brain away from the pushbutton setup. Doing rotaries for the first time.

Only problems I have had was the Lorin flat spots on the shaft for the knobs and one of the T-Pad pots fell apart and had to epoxy it back together. Now all I need is to light those Sifams somehow and put a Stagefright logo on it. LOL. Thanks everyone once again. And Kato for his great BOM.

When this is done it will be my most used compressor and passed down to my son someday.  :)
(http://www.stagefrightrecords.com/21176.JPG)
Title: Re: 1176LN Rev D DIY
Post by: canidoit on December 06, 2009, 10:16:41 PM
I haven't done any calibrations recently. But will soon. Maybe I can help you then.

I have been too busy for projects lately. Everyone always shows completed projects so I figured I would show mine "In progress". I have 4 days off and working like crazy to complete it. Wish me luck.

And thanks again Mako and Ed and Mike at hairball.

I used the flying saucer heatsinks on the output transistors and a bigger heat sink on the regulator. Neither are nessessary but I thought it looked cool. It powers up fine with no explosions or smoke. Just gotta get my brain away from the pushbutton setup. Doing rotaries for the first time.

Only problems I have had was the Lorin flat spots on the shaft for the knobs and one of the T-Pad pots fell apart and had to epoxy it back together. Now all I need is to light those Sifams somehow and put a Stagefright logo on it. LOL. Thanks everyone once again. And Kato for his great BOM.

When this is done it will be my most used compressor and passed down to my son someday.  :)
(http://www.stagefrightrecords.com/21176.JPG)
Very neat job mate. I like your layout!
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 07, 2009, 10:29:04 PM
Still plugging away with wires LOL. I did all the shielded ones first. But my eyes and brain have given out and know it is time for a rest. Guess it will take 2 more days but time has run out. Will have it done soon tho. And the Skylar flowchart is useless for a rotary build. But Mnats offered a great rotary wiring thing at his site. Which is now mnats.net so his original links don't work.

John
Title: Re: 1176LN Rev D DIY
Post by: Stagefright13 on December 09, 2009, 10:19:24 PM
So here goes my first rotary build. After reading Mnats site it is actually easier. Getting ready to hook it to my stuff. And calibrate. I ordered the link kit from Mike at hairball and is on the way. Still didn't hook up my lights. ;)

(http://www.stagefrightrecords.com/211763.jpg)

Title: Re: 1176LN Rev D DIY
Post by: ilfungo on December 10, 2009, 07:04:35 PM
ciao
about a year ago I bought on ebay a output transformer  for 1176
No. 11148 apparently old (who sold it to me told me that he was an original Urei processor) without any other written ...
I think it is the processor used in the Rev F
Can you tell me something?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 06, 2010, 09:32:34 AM
Just a quick substitution question; I am having trouble sourcing R32, the 39 ohm resistor.  It's been on backorder for a while and I found some 39.2 ohms locally.  Would this small substitution in the line amp cause any issues? 

From my limited schematic experience, I would think it based on R32's position it would be fine, but I thought I would check.

Thanks!
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 06, 2010, 09:50:13 AM
Just a quick substitution question; I am having trouble sourcing R32, the 39 ohm resistor.  It's been on backorder for a while and I found some 39.2 ohms locally.  Would this small substitution in the line amp cause any issues?  

From my limited schematic experience, I would think it based on R32's position it would be fine, but I thought I would check.

Thanks!

Yes that is fine.

I think I remember reading that the original UREI units used 20% tolerance resistors?!  That may have been the typical tolerance at the time.

Mike
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 06, 2010, 01:12:49 PM
Thanks for the info! 
Title: Re: 1176LN Rev D DIY
Post by: mpc3000limited on January 07, 2010, 12:10:40 AM
(http://www.stagefrightrecords.com/21176.JPG)

Looking nice so far!  ;)
Do you have a shot of the front panel? I am trying to decide on front panel designs for my 2-1176 Rev D's or spend the extra and make 2 regular blackface case units...
Title: Re: 1176LN Rev D DIY
Post by: luis on January 09, 2010, 06:57:55 PM
Hi,

I noticed an intermittent noise in my compressor that only goes away when the input attenuator is completely turned off, or when I disconnect the input transformer from the main PCB. So. While trying to figure the problem (checking for shorts,etc) I noticed that the + and -  pads in the input transformer PCB have continuity. Can someone tell-me if this is normal  ????

Thanks
Title: Re: 1176LN Rev D DIY
Post by: bdubya on January 10, 2010, 03:05:19 AM
Doesn't sound right.  Is your transformer soldered snug against the PCB, or lifted up off it slightly?  I seem to recall someone noting the potential for shortz from the traces to the can if its mounted flush against the pcb . . .
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 10, 2010, 06:41:39 AM
I noticed that the + and -  pads in the input transformer PCB have continuity.

Is the transformer installed?
Title: Re: 1176LN Rev D DIY
Post by: luis on January 10, 2010, 09:04:22 AM
Thanks for all your help,

bdubya: I think you are referring to to the the links on the pcb. They are not touching the transformer.
Mnats: The tranformer is mounted!

Since I think the countinuity test measures the resistance, maybe the problem is my DMM that is not accurate. In my dmm the resistance is 12.
Is there any way  to isolate the problem, for example connecting some signal directly to the main PCB + and - pads, without passing in the input transformer ??



Thanks
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 10, 2010, 03:31:06 PM
Mnats: The tranformer is mounted!

Then you are measuring the DC resistance of the transformer primary winding which should be low. A better test might be to run a signal into the primary and look at the secondary output. Push on the transformer and move it around - if the signal changes then you may have found your intermittent problem.
Title: Re: 1176LN Rev D DIY
Post by: luis on January 10, 2010, 07:37:06 PM
Hi,

I noticed an intermittent noise in my compressor that only goes away when the input attenuator is completely turned off, or when I disconnect the input transformer from the main PCB. So. While trying to figure the problem (checking for shorts,etc) I noticed that the + and -  pads in the input transformer PCB have continuity. Can someone tell-me if this is normal  ????

Thanks


Problem solved:
I had a short in my input cable! Funny how these rare things only happen when we are not expecting!
The Unit is compressing and sounding excellent.

Thank you all.
Calibrating... ;D
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on January 11, 2010, 01:44:56 PM
Hi D builders

I'm having a problem with hooking up my 12v Hairball VU lamp...

OK I understand I can tap into the juice off the AC PT secondary which is roughly 28.4VAC.
I need to use about 220ohms to drop this to 12ish VAC right??

I found a couple 470ohm resistors so wired them in parallel & that gives me a reading of 230 ohms.
So here's where I'm confused...
I attach the pair in parallel to one leg of the PT secondary (at the board) & measure
from the PT center tap to the resistors & I still get 28.4VAC Shouldn't I see a drop in voltage??

Cheers
Sean
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 11, 2010, 03:01:30 PM
So here's where I'm confused...
I attach the pair in parallel to one leg of the PT secondary (at the board) & measure
from the PT center tap to the resistors & I still get 28.4VAC Shouldn't I see a drop in voltage??

Is the load (lamp) attached?
Title: Re: 1176LN Rev D DIY
Post by: Ringwraith on January 11, 2010, 03:08:57 PM
No, I wanted to make sure I had a proper voltage before frying the lamp. Is this my problem?  :-[

Cheers
Sean

OK I took a leap of faith... lol
Lights up good & the voltage is 9.6 between the light lugs.
I'm using 1W Metal Oxide resistors in parallel. If I remember
correctly, this doubles the wattage so is 2W enough for this drop?
The resistors are getting a bit toasty.

Thanks
Sean
Title: Re: 1176LN Rev D DIY
Post by: luis on January 12, 2010, 02:55:38 PM
I'm having problems with the discrete meter circuit callibration: When I turn the trimmer Full CW or Full CCW, the meter does not move.
Checked solder, cables, and everything seems OK.

Did a search on the forum and found that some members had problems with this step, but none of them with a problem similar to mine.

Can someone help?

Thank you all
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 14, 2010, 02:01:39 AM
IT LIVES!!!

Hey just wanted to put out a huge THANK YOU to the prodigy forum.  I have been wanting to get into electronics more and this was my first real DIY project.  I have done some paint by numbers stuff, like the SCA pres (which sound great BTW) but I really wanted to actually learn a little more about what I was doing.  I still have a long way to go but the 1176 fired up first thing.  I was a little concerned because it wasn't compressing immediately but the Q bias was waaaaaay off.  So after a very quick adjustment, its compressing and sounds great. 

I will properly calibrate it tomorrow and keep my fingers crossed that nothing burns up, but so far so good.
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on January 14, 2010, 08:51:53 AM
Hi guys

I would like to make a rev D with Homnite Little Demon
any of you has already done?
can bring benefits to the sound?

Thanks :)
Title: Re: 1176LN Rev D DIY
Post by: pietro_moog on January 14, 2010, 03:05:45 PM
hey fungo!

guys,in never thought about it.
i used metal film resistors, panasonic and wima caps, like a lot of people around here.
does vintage models caps and carbon comp resistors give a more pleasant sound?
is that so much different?
in the simplest term, does a 1176 with metal film res and modern caps sound anything like the original?
Title: Re: 1176LN Rev D DIY
Post by: canidoit on January 16, 2010, 06:35:28 AM
The third calibration video is pretty good. It looks so much easier to do that third calibration process with that video.
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 17, 2010, 01:04:24 AM
Hey Canidoit, thanks for all the tips on my build BTW.

I thought I would include at least one pic of the insides.  Nothing extraordinary here; pretty standard parts based on some of the BOM's floating around and the basic parts from hairball.  I bought enough components and boards for two but I think I may populate my second board with all carbon and old school components instead to see if there is any audible difference. 

(http://i859.photobucket.com/albums/ab153/T-MF-Rex/mnats%201176%20build/IMG_0343.jpg)

I cleaned up the wiring a bit more before I buttoned her up, set the resistor for the VU lamp apart from the wire with it and a few small things.  Being my first major project the wiring is pretty messy but to my surprise it is totally quiet with no hum or any noticeable noise.  I didn't even scrape the paint back for the grounds.  I used Mogami balanced console cable for all the balanced connections, as I had a bunch left over from wiring my patchbays.  I love that stuff because it is so small but still really quiet.

Anyway thanks again for this forum!  (Oh and if anyone sees anything wrong with the insides, feel free to let me know!)
Title: Re: 1176LN Rev D DIY
Post by: canidoit on January 17, 2010, 04:38:07 AM
Hey Canidoit, thanks for all the tips on my build BTW.

I thought I would include at least one pic of the insides.  Nothing extraordinary here; pretty standard parts based on some of the BOM's floating around and the basic parts from hairball.  I bought enough components and boards for two but I think I may populate my second board with all carbon and old school components instead to see if there is any audible difference.  

(http://i859.photobucket.com/albums/ab153/T-MF-Rex/mnats%201176%20build/IMG_0343.jpg)

I cleaned up the wiring a bit more before I buttoned her up, set the resistor for the VU lamp apart from the wire with it and a few small things.  Being my first major project the wiring is pretty messy but to my surprise it is totally quiet with no hum or any noticeable noise.  I didn't even scrape the paint back for the grounds.  I used Mogami balanced console cable for all the balanced connections, as I had a bunch left over from wiring my patchbays.  I love that stuff because it is so small but still really quiet.

Anyway thanks again for this forum!  (Oh and if anyone sees anything wrong with the insides, feel free to let me know!)
Those Hairball cases look pretty slick. Well done mate  :). If you are going to go old school on your next build, also get the UTC transformers for it I reckon.

Be careful with that fat chunky resistor for the VU lamp. That gets very very hot! I am not sure how far apart that black cable is from the fat resistor but after a while, like years maybe, that black cable near it might start feeling the effect of the heat and also the paint below maybe?? Better to make a nice separation now than later on, which is a pain in the ass once you have racked the whole unit.

Hairball and others do this 2 little resistor in parallel version which they hang off the VU meter.
(http://www.ine-kpro.com/diy/1176/images/vu.jpg)
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 17, 2010, 10:49:39 AM
Thanks, yes I untwisted that and set the resistor a couple of inches from everything, the case and the other wire, with some plastic ties. 

yes the Hairball case is amazingly easy to use.  Really really nice and simple to work with.  I definitely wanted a case as my metal working skills and bad to say the least.
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 17, 2010, 02:36:25 PM
Awesome!

Nice to see the case used is a finished build so quickly.   :)

I used two resistors in parallel because I didn't have an appropriately valued (R and W) single resistor.

Thanks,

Mike 
Title: Re: 1176LN Rev D DIY
Post by: T-rex on January 17, 2010, 02:46:15 PM
Yeah, I had the board stuffed and all the parts waiting, as soon as I got the case I just put it together and wired up all the off board connections.

I know there is another thread for the cases, but I have to say their great.  The standoffs make everything very easy to put together and shaved a ton of time off the assembly.   
Title: Re: 1176LN Rev D DIY
Post by: sws2h on January 18, 2010, 01:00:14 PM
Has anyone used a Jensen JT-11 input transformer in their Rev D? I'm considering building on using it and the UA-5002 T2 output transformer, if possible.
Title: Re: 1176LN Rev D DIY
Post by: 3nity on January 20, 2010, 02:49:36 AM
Hi guys.
Looking to build 1 of those i have almost everything now.
one question to start with...I have a 600:600 Jensen transformer.
I was wondering if this could work in the Rev D?

Thanks.
Title: Re: 1176LN Rev D DIY
Post by: luis on January 20, 2010, 09:03:47 AM
I'm having problems with the discrete meter circuit callibration: When I turn the trimmer Full CW or Full CCW, the meter does not move.
Checked solder, cables, and everything seems OK.

Did a search on the forum and found that some members had problems with this step, but none of them with a problem similar to mine.

Can someone help?

Thank you all

Well discrete meter calibration is done, but there is no way to do the tracking adjustment step:

Turning or removing the R44 out the circuit does not change the meter needle position. Checked solder, checked the trimmer, changed some transistors (q7-q10) like suggested by someone in the forum… no solution!
The 2n5457´s FETS are hfe matched by a cheap multimeter, so maybe this is the cause of the problem. Is there any hint or clue of what might be?

Regarding the audio and compression, everything seems working just fine, I just have a small HUM that I almost 100% certain that is caused by the toroid that will be replaced, and I also noted that if the input cable is connected, even if there is no signal if I put the Attenuator past half way, and the Output at Max there is some noise (the converters should be clipping). If the input cable is disconnected this doesn´t happen. His this the normal behavior?
Thank you all,
Luís
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on January 20, 2010, 09:13:33 AM
hello
Can you tell me if the orange drop instead of wima may give some advantage to the  REV D sound?
I want make a old style rev D with carbon composition resistor and orange drop caps...
thanks
Title: Re: 1176LN Rev D DIY
Post by: trancedental on January 21, 2010, 11:30:38 AM
I'm  wiring up a 1176D V2 with Hairballs Pushbutton instructions, & am wondering why the one of the molex ratio PCB connection out wires  is supposed to be wired to the attack pot when the attack pot is also wired to the main PCB board 19 on pictures of builds & diagrams, can someone clarify the attack pot wiring from the ratio PCB? I'm using the meter pcb pushbuttons for disabling the attack switch.

I've spent ages trying to work this out with schematics & diagrams / pictures but am much too brainless to work out what is supposed to be exactly happening?  ???

Thanks JK
Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 21, 2010, 11:49:43 AM
I'm  wiring up a 1176D V2 with Hairballs Pushbutton instructions, & am wondering why the one of the molex ratio PCB connection out wires  is supposed to be wired to the attack pot when the attack pot is also wired to the main PCB board 19 on pictures of builds & diagrams, can someone clarify the attack pot wiring from the ratio PCB? I'm using the meter pcb pushbuttons for disabling the attack switch.

I've spent ages trying to work this out with schematics & diagrams / pictures but am much too brainless to work out what is supposed to be exactly happening?  ???

Thanks JK

I have a new guide that explains it better.

http://hairballaudio.com/docs/FET_Compressor_PCB_Board_Info_V2.pdf

The GRN connects to the bypass switch.  When pad 22 is connected to GRN on the ratio board you are compressing.  On the earlier documentation I indicated "Attack Pot" because I have always put the GR bypass on the attack pot.  Wrong on my part.

Check out the new doc.

Thanks,

Mike
Title: Re: 1176LN Rev D DIY
Post by: ChrioN on January 24, 2010, 11:23:08 AM
Perhaps a strange question, but: Why did they use odd resistors like 38.3k, 44.2k and 7.68k when the resistors used had a tollerance of 5%? Were these values more common and standardised back in the days?
Title: Re: 1176LN Rev D DIY
Post by: ChrioN on January 25, 2010, 02:08:49 PM
Anyone?  :)
Title: Re: 1176LN Rev D DIY
Post by: 3nity on January 25, 2010, 05:56:45 PM
Wow...
I was stuffing my board and i couldnt find any 38K3 resistor and the same question crossed my mind!
i ended up using 2 resistors...1 x 36K + 2.2K...
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 25, 2010, 08:28:56 PM
Perhaps a strange question, but: Why did they use odd resistors like 38.3k, 44.2k and 7.68k when the resistors used had a tollerance of 5%? Were these values more common and standardised back in the days?

If you look at the original schematic you'll see that they didn't use these values as they weren't at all common.
Title: Re: 1176LN Rev D DIY
Post by: ChrioN on January 25, 2010, 11:42:29 PM
you're right :o thats quite embarrassing. How come you didn't use the values from the rev A schematic?

Perhaps a strange question, but: Why did they use odd resistors like 38.3k, 44.2k and 7.68k when the resistors used had a tollerance of 5%? Were these values more common and standardised back in the days?

If you look at the original schematic you'll see that they didn't use these values as they weren't at all common.
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 26, 2010, 02:51:32 AM
you're right :o thats quite embarrassing. How come you didn't use the values from the rev A schematic?

Because it's the Rev D?

Seriously, the reason I took the sidechain from the later version was primarily to save having to select resistors to tweak the circuit.
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 26, 2010, 09:12:15 AM
Does anyone have a DC voltage chart for the 1176LN rev D? Or, if you've got a working one on the bench, can you measure B,C,E voltages WRT ground?

I'm building a Purple MC76 (which is closest to the D), and I'd like to troubleshoot some problems I've got with the meter section (I can't get it to null R74).

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: edanderson on January 26, 2010, 03:43:04 PM
do you have r44 disconnected?  the MC77 PCB included a jumper for connecting and disconnecting it.  during the calibration, you may have to do each step a few times until everything is correct.

does your front panel meter zero adjust control work?  can you get the needle to point to 0dB?

ed
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 26, 2010, 04:00:04 PM
Hi Ed,


R44 is disconnected.

Here are my symptoms:
- The front panel meter adjust seems to work backwards CCW brings the needle up the scale. Is this normal? It seems counter intuitive, so I'm guessing that it's not normal.
- When passing audio through the unit, it will compress, and when compressing the GR needle moves up the scale (like into the +ve range), instead of down the scale. It's like the whole meter is working backwards for the GR circuit. I've flipped points 28 & 29 and it makes no difference.

If I try to null using the itterative procedure (while metering R74), I keep winding both R71 and R75 to the ends of their range and have 2.5 V across R74.

It's weird....

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on January 26, 2010, 04:02:02 PM
R44 is disconnected.

Are you putting the meter at 0VU before you adjust meter NULL?

Mark
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 26, 2010, 04:20:06 PM
R44 is disconnected.

Are you putting the meter at 0VU before you adjust meter NULL?

Mark

Yup... I used R71 (front panel adjust) to get the VU to read 0 in GR mode. Bringing this pot CCW raises the needle position on the VU....but every time I adjust R75 from there the VU needle keeps falling, and I need to keep turning R71 CCW to bring it back up. Eventually I get R71 all the way to the CCW stop, and I still can't null R74.

On your build, when you turn the front panel pot CCW, which way does the VU meter needle move?

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: dmp on January 26, 2010, 04:41:46 PM
Hello,
I have a few observations that I thought I would share with the group. I may be way off since I am building a pair of 1176's for the first time.  And they are certainly not working the first time! But I am having a great time trying to figure them out.
- In the calibration video, mnats says the Qbias trimpot should be adjusted all the way to ground, and then dialed back to bring the fet into conduction. I think this is reversed actually, the Qbias should actually be adjusted fully negative, since the fet Vsource is equal to ground. The fet becomes more conductive as Vgs approaches zero, I believe, i.e. when Vg is more negative the the resistance of the fet is high, i.e. no gain reduction of the input signal. I discovered this because I accidently used a 560 ohm for r9 instead of 560k - which made for a huge reduction of the input signal no matter what the fet was doing! Really a fun gremlin to try to find.
- The setting of the input attenuator (from hairball) affects the input signal noticably. When feeding the 1176 with a function generator with output impedance of 600 ohms, the signal was being lugged down depending on the T-attenuator position. If the T-attenuator was constant 600 ohms impedance, it would not show this behavior. I took some measurements of the T-attenuator, and calculated the impedance (assuming 600 ohm output impedance: Z = R1+1/((1/R3)+(1/(R2+Zout)) ))
The results showed that the impedance of the T attenuator went from 520 ohms at fully ccw to 382 ohms at fully cw. I hooked this up like the picture earlier in this thread, and I cannot think of a different way to wire it. The two attenuators I have showed appx the same behavior (which is good since I am trying to make matching units for dual mono / stereo). I'm curious if I am doing something wrong? I know a lot of work went into finding a source for this component, and I do not mean to offend anyone.

Thanks to everybody who participates in this forum & especially Mike at Hairball Audio for the great parts and Mnats for the great boards!

Dan

Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on January 26, 2010, 05:05:41 PM
Yup... I used R71 (front panel adjust) to get the VU to read 0 in GR mode. Bringing this pot CCW raises the needle position on the VU....but every time I adjust R75 from there the VU needle keeps falling, and I need to keep turning R71 CCW to bring it back up. Eventually I get R71 all the way to the CCW stop, and I still can't null R74.

On your build, when you turn the front panel pot CCW, which way does the VU meter needle move?

Cheers

Kris

I got a little confused when I adjusted the meter on my build.

This is what worked for me.

Take R44 out of circuit.
Center Null Pot (R75)
Volt meter across R74, on my build TP10/11

Meter Calibration

A) Zero VU with FP Meter Adj (R71)
B) Adj Null Pot (R75) for .00 volts across R74

Repeat A&B until both conditions are met.

Put R44 back in circuit, then do your 10db GR adjustment

Done.

I would verify the resistor values around the meter circuit if you can't get
it calibrated; R73: 680R, R74: 2M7, R76: 8K2, etc. Also check for shorts.

My FP adj works as follows: CW: VU Needle up, CCW: VU Needle down

You may have to swap the leads on your FP adj pot.

Mark
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on January 26, 2010, 08:25:58 PM
ciao
Can you tell me  a potentiometer ( easy to find) for  the  FP 0 adjusting?
Mouser code?
Farnell code?
Thanks 
Title: Backwards meter problem solved...
Post by: DrFrankencopter on January 26, 2010, 11:02:58 PM
Made some serious progress. Did a ton of probing around the meter circuit and ultimately found that Q12 had a dead short between emitter and collector. The short wasn't at the transistor, it was at R74 and R44. The pads on my MC76 PCB were really close together in this area, and I had to do a little bit of cutting to clean it up.

The meter zero's & nulls now.

Cheers

Kris
Title: Re: Backwards meter problem solved...
Post by: Biasrocks on January 26, 2010, 11:46:27 PM
The meter zero's & nulls now.

Great!  8)

Mark
Title: Re: 1176LN Rev D DIY
Post by: julien31 on January 27, 2010, 02:23:03 AM
I made 3 rev D versions and for all of them i had to change R44 for proper calibration. The 1K trim pot had to be changed for a 2K to achieve the 10dB calibration. Has any of you had the same problem? Is it the way to go?
Thanks in advance
Julien
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 27, 2010, 09:26:09 AM
I need to set  the T&C resistor that attaches to the 20:1 ratio switch to set the threshold of compression....what range should I be looking at? Currently I have no resistor installed, and I get no compression in 20:1...

Also, is there a schematic for Mnats 1176D? I realize its based on the Urie schematic & part #'s, but there are differences, and I can't seem to find a schematic anywhere. I'd like to reference it for my MC76 build...

Also, on the Mnats 1176D Is the 20:1 ratio threshold resistor on the main PCB, or are people hanging it off the switch? I'm curious because there's no place for it on the Hairball audio ratio PCB...

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: kilmister on January 27, 2010, 10:50:43 AM
Also, is there a schematic for Mnats 1176D?

Yes there is: http://mnats.net/1176_revision_d.html

-Paavo
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 27, 2010, 11:21:57 AM
Also, is there a schematic for Mnats 1176D?

Yes there is: http://mnats.net/1176_revision_d.html

-Paavo

Many thanks....

A note for Mnats, the link to the 1176 rev d page from this page: http://mnats.net/1176.html does not work (it needs .html added to the end).

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 27, 2010, 11:30:28 AM
I checked the schematic for the Mnats RevD, and there is no T&C resistor from the 20:1 switch to the sidechain input. This resistor is present on the Urei Rev D schematic, and on the Purple MC76. It looks like it will affect (raise) the threshold for the 4:1, 8:1, and 12:1 settings.

Any reason why this resistor isn't included in the mnats design?

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: trancedental on January 27, 2010, 11:54:38 AM
I have a new guide that explains it better.

http://hairballaudio.com/docs/FET_Compressor_PCB_Board_Info_V2.pdf

The GRN connects to the bypass switch.  When pad 22 is connected to GRN on the ratio board you are compressing.  On the earlier documentation I indicated "Attack Pot" because I have always put the GR bypass on the attack pot.  Wrong on my part.

Check out the new doc.

Thanks,

Mike

Thanks Mike, Thats all sorted out now. Just one more silly question, which is the exact positive / negative + & - connections for the VU meter on the Hairball Pushbutton Meter PCB?

My 1176 is passing audio & seems to be compressing but the meter is not responding so far, so I just need to confirm the meter wiring as I've tried it both ways without much difference ???
Title: Re: 1176LN Rev D DIY
Post by: dmp on January 27, 2010, 02:04:11 PM
I think the top VU is + on the Hairball Meter PCB... the pads are: Y  X  28  29   VU(-)  VU  (+)
That's how I hooked mine up and the meter is working correctly for signal and GR.
Here is a wiring diagram (based on the really nice one Skylar made) that uses the Hairball supplies... like the EA-5002, pushbutton switches with the hairball pcbs, the hairball attenuator, the attack SPDT switch from Mouser, and a zero set pot on the hairball faceplate.
Sorry this is messier than Skylar's nice original ;)
 
Title: Re: 1176LN Rev D DIY
Post by: mnats on January 27, 2010, 03:16:32 PM
- In the calibration video, mnats says the Qbias trimpot should be adjusted all the way to ground, and then dialed back to bring the fet into conduction. I think this is reversed actually, the Qbias should actually be adjusted fully negative, since the fet Vsource is equal to ground. The fet becomes more conductive as Vgs approaches zero, I believe, i.e. when Vg is more negative the the resistance of the fet is high, i.e. no gain reduction of the input signal.

I think this was also mentioned by the uber-helpful gswan in the "All thing G1176" thread. I will correct the video one day, but I guess most people will end up turning the trimmer without getting out a multimeter or looking at the spec sheet anyway!

Any reason why this resistor isn't included in the mnats design?

Or the G1176? The prevailing wisdom when the board was first made was that the T&C part was done to confuse cloners. Even if not true, it worked!

If you are motivated to go through the measurments, it's easy enough to add, isn't it?
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 28, 2010, 09:06:36 AM

Or the G1176? The prevailing wisdom when the board was first made was that the T&C part was done to confuse cloners. Even if not true, it worked!

If you are motivated to go through the measurments, it's easy enough to add, isn't it?

Sure, it's no problem. I only even noticed it because I had 'reverse engineer' the Hairball Audio ratio & meter boards against my Purple MC76 schematic, and found that the T&C resistor was missing (and the 10 Meg resistor was in a different position). I was having some issues with my 20:1 ratio, and thought that the lack of T&C may have been the root cause. In the end, my problems were a combination of a 5.6k resistor instead of 56k, and a poor solder connection on one of the 20:1 switch poles. I'm going  to do some subjective listening tests and see if the thresholds are good enough without the T&C.

Switching subjects...On my MC76 when doing the GR meter tracking adjustment, I ended up needing 2.5 kOhms resistance for R44 to make the meter zero, and track 10 dB of gain reduction. I notices on the Mnats 1176D, R44 has a maximum value of 1k. Is this indicative of a problem with my build (I didn't use matched FETs)? My meter read less than 10 dB GR when R44 was set to1k, and the only way to bring it up was to increase R44. Perhaps a 2k pot for R44 might allow for more variability...

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: edanderson on January 28, 2010, 11:16:05 AM
on the mc77 we used a 2k trimmer for r44.  it all depends on the FETs -- some will bias with just a 1k trimmer, most with a 2k, but i've seen some people use even a 5k trimmer on their mnats builds.  the FETs are really all over the place and if you aren't doing some selection beforehand, 1k may not cut it.  i think the screen on the v2 mnats PCB even indicates a 2k trimmer for r44, but i could be wrong about that.

glad to hear that you're getting closer kris.

ed
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 29, 2010, 09:18:58 AM

glad to hear that you're getting closer kris.

ed

I'm 99% done Ed...many thanks for your help and encouragement. The only thing left is to do the distortion calibration, and decrease the lamp current. I used a 7812 fed from the 40V post recitifer to power the lamp, and despite being on a decent heatsink it's getting too hot for my tastes. I'm going to experiment with a series resitor with the lamp and see if I can get the current down while still having some brightness. If that doesn't work, I'll try subbing out the lamp for some LEDs.

Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: edanderson on January 29, 2010, 10:46:11 AM
since the 7812 has to drop the voltage from ~40VDC down to 12VDC, that will be a significant amount of power unless you reduce the current in the lamp quite a bit.  you could put a resistor in series before the 7812 to drop the pre-reg voltage, and keep the current in the lamp the same.

if you have a way to look at the THD signal on a scope or do an FFT of the signal, you may be able to fine tune the distortion measurement.  there is a range on the trimmer that will give you a minimum value, but within that range you can adjust the harmonic content a little if you have the means to measure it.

ed
Title: Re: 1176LN Rev D DIY
Post by: DrFrankencopter on January 29, 2010, 12:26:55 PM
since the 7812 has to drop the voltage from ~40VDC down to 12VDC, that will be a significant amount of power unless you reduce the current in the lamp quite a bit.  you could put a resistor in series before the 7812 to drop the pre-reg voltage, and keep the current in the lamp the same.

if you have a way to look at the THD signal on a scope or do an FFT of the signal, you may be able to fine tune the distortion measurement.  there is a range on the trimmer that will give you a minimum value, but within that range you can adjust the harmonic content a little if you have the means to measure it.

ed

I've already got a 75 ohm 3W resistor before the 7812, which should drop the voltage by 7V. But there's still something like 2W being dissipated in the heatsink. I'm going to try looking for alternate lamps...perhaps I can skip the 7812 entirely.

For the THd measurement I was planning on using Wavelab's FFT analyzer, and a 1kHz sine input...hopefully it'll be good enough to show gross adjustment problems. I'll attempt to adjust for minimum high harmonics.


Cheers

Kris
Title: Re: 1176LN Rev D DIY
Post by: Biasrocks on January 29, 2010, 12:47:30 PM
Do you need to run the lamp DC?

On my build I ran a 220 or 240 ohm resistor off the power transformer secondary to nicely light my Hairball meter.

Mark
Title: Re: 1176LN Rev D DIY
Post by: trancedental on January 29, 2010, 08:04:17 PM

Here is a wiring diagram (based on the really nice one Skylar made) that uses the Hairball supplies... like the EA-5002, pushbutton switches with the hairball pcbs, the hairball attenuator, the attack SPDT switch from Mouser,
 

Cheers Dmp ;D

On your wiring diagram, there's two wire connections leading from the Gain Reduction Bypass switch function included on your DSPT switch (Attack Pot) used on your build. From the off position lug one goes to Ratio board BLK & one to PCB ground (on the Mnats board "G" I assume?)

I have wired my Gain Reduction Bypass / disable function on the meter pushbutton board (instead of the usual on / off power switch)  as indicated  in Hairballs instructions http://hairballaudio.com/docs/FET_Compressor_PCB_Board_Info_V2.pdf (http://hairballaudio.com/docs/FET_Compressor_PCB_Board_Info_V2.pdf) the wiring layout I used is the same as in the last diagram instructions with the 22 going to the main board & the BLK & GRN going to the ratio board.

So I don't actually have the extra wire fitted which in your case goes to the point "G" on the main board, I have checked for continuity between the "G" & "22" when I engage my GR bypass switch without success.

So do I need another extra wire from the BLK lug on my switch to "G" then?

Cheers JK

Title: Re: 1176LN Rev D DIY
Post by: Hairball Audio on January 30, 2010, 02:50:06 AM
Ratio BLK and Bypass BLK need to be connect together as well as to signal ground at some point.

Usually the shield from 22 carries the signal ground from the board to the bypass or ratio switch.

Mike
Title: Re: 1176LN Rev D DIY
Post by: dmp on January 30, 2010, 11:30:41 AM
JK, I think it is a little confusing because in the sketch the connection to signal ground for the ratio and bypass BLK is connected through the wire shielding, as mike says. This is an unusual way to do things - usually a shielding is only connected at one end and a seperate wire would be used to connect signal ground. But, it is easier and works fine in my build.
You should have continuity between PCB "G" and Ratio "Blk". If you do not, you can run another wire to connect the signal ground between the two.
Title: Re: 1176LN Rev D DIY
Post by: patterson on January 30, 2010, 02:17:02 PM
I got the kit from Hairball and the revD worked right away. Having only used software versions of the 1176 before, I am amazed at the difference it makes to use the actual unit.  Very musical compression. Thanks to you and to Mnats for a great project.

I noticed that some people are using tantalum caps instead of the cans in some cases.  Does this make a difference in the sound?
Title: Re: 1176LN Rev D DIY
Post by: edanderson on January 30, 2010, 02:56:09 PM
in some of the older original units, two caps in the sidechain were tantalum because they were lower leakage than the electrolytics available at the time.  most electrolytics today aren't leaky enough to cause any issues, so it isn't a big deal.  but you can safely use tantalums if you want. 

i think some people might notice a sonic difference if you use a tantalum cap in the audio signal path, but just as electrolytics have changed, many of today's tantalums are different from the old ones (for example those found in old neves).  feel free to experiment with different caps once you've got it working.

ed
Title: Re: 1176LN Rev D DIY
Post by: trancedental on January 30, 2010, 07:53:40 PM
Cheers Echo North & Smd, I'll have to go through the exact wiring & check everything again, bit arkward as my home internet isn't working at present so troubleshooting is now harder ::)

Anyway I had the 1176D on for 5 hours today, the board voltages are -9.6 / + 29.8 which is hopefully just within range & the heatsink seems cool enough.  I ran tracks through it & tried some DI bass & guitars. Sounded very nice with my '67 Gretsch Country Gent ;D

Its seems to be working & compressing but with some slight problems, VU not working (I must have this wired up wrong  ???  ) but I managed to do the q-bias & some of the other calibration tasks by using another external VU meter.

Attack switch full clockwise starts to stutter especially on drum tracks, & the -20 & -4 compression settings have a very low level bubble type noise, the other compression settings are fine.

Just a matter of doing some more checking & rewiring should finish it off

Title: Re: 1176LN Rev D DIY
Post by: T-rex on February 04, 2010, 09:35:00 PM
Is there an audible difference between using the 2N5088 and the 2N3037s?  I have a set of both and was going to maybe socket the board this time so I could switch between them but before I do that is there enough of a difference to matter?  I tried searching but as you can imagine "transistor" and "sound" brings up pretty much every thread. . .
Title: Re: 1176LN Rev D DIY
Post by: dmp on February 10, 2010, 04:33:26 PM
I've been looking at the signal preamp section of this cicuit for a couple days and I'm wondering if anyone has figured out the design? I'm having trouble as the gains I'm calculating seem really large. Total voltage gain of ~100 dB? Does anyone know if this is expected? Voltage gain of Q2 >2000!  I don't have a circuit simulation program so I may have made a mistake in the equations. Basically, I used ohms law and transistor rules to simulate the preamp in an equation solver. 
I started looking at it because a fairly large input signal (a few volts pk-pk sine wave) shows negative clipping due to (I think) the bias of the emitter follower, Q14, but also perhaps by the high gain of the preceding amp stage, Q3. I thought maybe changing the bias of Q14 might be an improvement in headroom since it is at ~4v - but I first wanted to understand why the revD had R12=920ohms (later revs increased this I think, maybe to increase the headroom at this stage?).  But I'm struggling to understand how the distortion trimmer changes the frequency response and if this feedback to Q2 is sensitive to R12, which sets the bias back to Q2.
I guess this is a build thread - if there is a better thread for this question I apologize
Dan
Title: Re: 1176LN Rev D DIY
Post by: bdubya on February 10, 2010, 06:40:55 PM
Is there an audible difference between using the 2N5088 and the 2N3037s?  I have a set of both and was going to maybe socket the board this time so I could switch between them but before I do that is there enough of a difference to matter?  I tried searching but as you can imagine "transistor" and "sound" brings up pretty much every thread. . .

Socketing them all is kind of nice, anyways, and since you already have the two different types . . . go for it!    I'm sure alot of folks would be interested to know your results. 
Title: Re: 1176LN Rev D DIY
Post by: ilfungo on February 12, 2010, 08:17:12 PM
hello
anyone know how I can connect as input OEP A262A2E?
Thanks
Title: Re: 1176LN Rev D DIY
Post by: astrovic on February 15, 2010, 04:21:22 AM
Hey guys - don't post here often but have got some valuable info from this thread and the Rev A thread while building this is baby, a dual 1176 with a Rev A and a Rev D:

Front (you can see the dual G1176 I built a couple of years back in the background):

(http://i93.photobucket.com/albums/l44/astrovic/Ermz1176013.jpg)

Rev A on the left, Rev D on the right:

(http://i93.photobucket.com/albums/l44/astrovic/Ermz1176014.jpg)

Rev A:

(http://i93.photobucket.com/albums/l44/astrovic/Ermz1176015.jpg)

Rev D:

(http://i93.photobucket.com/albums/l44/astrovic/Ermz1176016.jpg)

Due to the tight space, I mounted the ratio boards in the floor and ran jumpers to the ratio switch.  This made front panel work easier, but added a lot of wiring!

I managed to keep the nuffiness to a minimum - just a couple of stupid mistakes that IO slowly cottoned on to.  I've been building long enough now to know that there's a 98% chance of human error causing the problems, so I just keep searching until I find the mistake!  Works nearly every time.

I'm down to 2 issues:

1. Calibrating the meter in GR mode is proving a challenge on both units.  I'm burned out on this build, so I'm going to park that issue for a while and come back to it later when the head is refreshed

2. I only ordered one bloody To-5 heatsink for the output transformer.  Dag-nammit!  You can see that the 2n3053 in the Rev A has the Flying Nun outfit on, but the Rev D is a nude dude. I