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General Discussions => The Lab => Topic started by: Purusha on September 17, 2006, 03:37:01 AM

Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 17, 2006, 03:37:01 AM
I am just curious, has anyone actualy compared the G 1176 with Purple MC76 or the original UREI version?

Maybe I will DIY one for my friend in the near future if the G 1176 sounds at least 80% close to the real thing. I have a 108% perfect clone of the original UREI but don't have the G 1176 to compare with.

Ohm Tat Sat
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 17, 2006, 04:05:19 AM
judging by a friend technician/producer the Purple was an exact replica of the original 1176. Maybe he was "parrotting" the commercial information...

I should ask him to checkout my 1176, that still needs a little tuning, so no cdirect comparison possible here.
I did' compare my version with my new bought 1176 and there's a significant difference. My 1176 has no iron built in yet, so I'm comparing apples and eggs  :evil:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 17, 2006, 09:40:21 AM
Question too simplistic.

Many different 1176's.

Purple is a replica of the BEST sounding 1176 in tha vast majority of people's experience.

G1176 is essentially a (near) replica of the latest version, long after the unit had lost the Class-A back end and begun to use the active front end.

I have built a pair of Purples, Finished building a few G1176's for people who haven't been able to get them tweaked/calibrated/working, and at work I have a Revision D Urei (the good one) and a revision G Urei (the late one) side by side.

G1176 is like the late silver-face. Very useful.

Purple audio 1176 is the VERY FINEST sounding replica that you can buy. Better then the Universal Audio reissue. The purple is the ONLY one with the exact circuitry of the revision D. The UA reissue is a very different front end.

My two Purple/Bloo replicas have been installed at a local rock studio for the last couple of months. I had to reclaim them to put in my compression rack. The studio also has a silver-face 1176 and is now sellling it. They tried Universal audio reissues and returned them. They have purchased a pair of Purple Audio MC77's.

Keith
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 17, 2006, 10:14:57 AM
Thank you Keith for your nice explanation  :thumb:

What about UA1176 vs G 1176? Any similarity here? My friend didn't like the UA version so if the G sounds the same than it's no go for G 1176 DIY.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 17, 2006, 12:21:01 PM
I'm not sure that 2 diy 1176 (with other brand components) will sound identical either. If you're after that classicsound buy a purple.
I have a UA and a clone, the UA get's favoured over the DIY 99% of the occasions. I need to pimp my diy 1176 urgent.

Don't forget to take iron, or no iron, into count too. My diy 1176 is without iron, plans are to change that first.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Rob Flinn on September 17, 2006, 12:49:20 PM
Keith said
Quote
Purple is a replica of the BEST sounding 1176 in tha vast majority of people's experience


I've had it said to me by a couple of people who know vintage gear that the Purples are lacking in gain compared to the excessive amount that the originals have.   I've never played with one myself to know, but these comments come from people whose opinion I respect.  Keith can you comment on this or do some tests against your rev D to clarify whether this is the case ???

Also when you compare the G1176 to a late model UREI is that with or without the input transformers & was it with Lundahl or OEP.    I have compared the G1176 to my revision H UREI`s & they do sound similar as you say.   The G1176 that I compared only had Lundahl output transformers.   Like you said there are many variables !

Tony dB said

 
Quote
I have a UA and a clone, the UA get's favoured over the DIY 99% of the occasions.


Do the people do a blind test to select their favourite or do they know which they're listening to ??


What, if any, apart from the Purple or original transformer could one use to recreate the class A output of the rev D with it's feedback winding.  Any suggestions anyone ?
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 17, 2006, 12:51:34 PM
Iron is a must for me  :wink:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Rob Flinn on September 17, 2006, 01:42:37 PM
Quote
Iron is a must for me


I notice you didn't add any to your GSSL !
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 17, 2006, 02:13:44 PM
Quote from: "Rob Flinn"
Keith said
Quote
Purple is a replica of the BEST sounding 1176 in tha vast majority of people's experience


I've had it said to me by a couple of people who know vintage gear that the Purples are lacking in gain compared to the excessive amount that the originals have.  

Hmm... not heard that, but I can certainly compare my bloo purple clone (built on a Purple MC76 PCB) with a Rev D at work and tell you for certain.

Keith
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 17, 2006, 02:22:50 PM
Quote from: "Rob Flinn"
Quote
Iron is a must for me


I notice you didn't add any to your GSSL !


No? You didn't saw my posts in some other thread? I have OEPs on the way for both GSSL units :wink:  :green:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: matthias on September 17, 2006, 02:32:49 PM
I think it doesn't make any sense to use transformers for the ssl unless you change the in/outout stage completely...
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Luny Tune on September 17, 2006, 07:27:09 PM
Actually it makes a lot of sense. :wink:
To me, anyways...

I have fitted both my GSSLs with trannies and it adds to the already nice flavour of the units, I think. Sometimes I just run the EVP 88 e-piano softinstrument in Logic through a GSSL without comping just to get get the sound of the trannies on it. It sounds great. :razz:
Also, apart from adding to the "fattening-up" of the mix the trannies also add to the sense of separation when inserting it on the master.

You should however replace the four 100 Ohm resistors with 22 Ohm ones in order to drive the trannies best. But apart from that it's a very very simple operation. I know that not everybody agree with me but I love what they do and will not build another GSSL without trannies in the outputs.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 18, 2006, 12:34:57 AM
i wouldnt abandon the g1176 just for historical inaccuracy.  remember that it is good deal cheaper to build than a purple with the kit, and i would not call the oens i've built anything but very useful.  besides, you calibrate it ;]  its what you want it to be.

pick your trafos.  dont even have to use oep's or lundahls.  try cinemag.  try jensen.  its all yours for the trying.  

if you want the exact same thing, and want to build it yourself, the purple's where it's at, if you're after that particular blend of 1176....   or better yet, find an O12, rip a urei eq output tx, and find yourself a good old daven 600 ohm t attenuator.

and then integrate that with the g1176 board.

how accurate does it have to be exactly?

but remember, there's a million things you can do with that g1176 board.  make it yours.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 18, 2006, 12:37:34 AM
but on vocals and overall i think its 'just perfect'

when its what i'm looking for of course
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 18, 2006, 01:45:41 AM
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
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 18, 2006, 05:07:52 AM
Maybe we should make some 4 and 8db GR sound files through what ever you've got. We just need one nice uncompressed vocal and instrument sample to run it through. I can run it through my UREI clone as well. We just have to ignore the fact of using different converters but this is not such a big factor IMHO. Any decent 96KHz converter should do.

What do you say? C'mon, let's have some fun  :green:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 18, 2006, 08:28:09 AM
Quote from: "Rob Flinn"


Tony dB said

 
Quote
I have a UA and a clone, the UA get's favoured over the DIY 99% of the occasions.


Do the people do a blind test to select their favourite or do they know which they're listening to ??


I often set up a few different compressors (ranging from DIY channelcomps, Distressors, Gyraf G10, UA1176, DIY1176, DBX, ...) tru subgroupsends. I don't tell anyone what they hear, they just pick what they feel flattering their instruments. I never found my DIY 1176 sounding as good as my UA 1176 (and I don't have any problem with that, I'm after extra colours most of the time). We've reached consensus numberous times, my DIY version doesn't even come close, lack of iron is a big factor of this. As I said, I need some serious pimping on the DIY1176 and iron is the very first thing to go for. No offense to the G1176 at all, I take full responsability for the "uncomplete" clone. I'm also sure that a lot of the 1176 built by people overhere, can seriously compete other variants. Just not mine. That's also the main reason I said
Quote from: "tony dB"
I'm not sure that 2 diy 1176 (with other brand components) will sound identical either.

there's so much variaty in all G1176 built that it is simply not possible to say what sounds better than what else...

And then there's TASTE and other elements in the mix, ...
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: t-wurst on September 18, 2006, 08:34:49 AM
i can compare my g1176 build with Lundahl Output Iron with two different 1176 Blackface and to my ears the DIY version win the shootout. I canĀ“t say what version of 1176 it was, but i would prefer my lundahl, especially in the "in your face" disciplin.
 
I can it also compare to an "Phoenix" Tube compressor but i think thats another chapter and should be discussed elsewhere.....  :grin:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 18, 2006, 08:35:03 AM
:oops:

and then I read the rest of what was posted after Rob's post and found myself repeating a lot...
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 18, 2006, 08:38:13 AM
Ed, Good to see you around again... I know that you're a busy man, and just abour the best placed to comment on this subject these days!  :wink:

Thanks for those input attenuators... they're the ones that I used in mine. -For what it's worth, they generated a couple of extra sales for Purple, since when the studio returned them to me, and determined that they didn't like the UA versions (which are basically the same output stage... almost) they called me and asked if there were ANY other 1176's out there that sounded like mine... I told them to try the Purple, -they did, and now they've ordered a pair. -They have a rev F/G 1176 and it's up for sale if anybody wants one...

From that account alone, and judging by the fact that the of two genuine UREI 1176's here, people generally reach for the top one (the older 'D' one, with the O-12 input tranny) thoughsome people profess to liking the lower one (the newer, transformerless-input 'G' version) for some specific things, like snares that need to stay particularly crisp under heavy GR...

I don't think that sound samples really help. Not everybody hears the same thing, different attack/release rates, differenc spectral content of (for example) different acoustic guitars mean that the 'boom' from some guitars will 'push' the GR harder, resulting in an overcompressed sound. The same amount of GR on a different guitar, or with the mic moved at an angle forther away from the soundhole exit, will produce a less 'pumped' sound even on the same comrpessor, so this really is a futile exercise in my opinion.

There are too many versions of the 1176 to generalise, but to my mind the best sounding revisions for overall work are D and E. The later ones compress fairly well, but the tonal characteristic is a little more 'spitty'. It's only slight, i hasten top point out, but it's vastly more significant to me than the difference between most mic preamps, which -to most people- is really only fairly slight. (I'm sure my mum couldn't tell the difference between any of 'em!)

So if you can't afford an early or even a late 1176, the G1176 is a phenomenally powerful tool to have at your disposal. But in my former life as a recording and mixing engineer, I know that you can move from studio to studio, see black-face 1176's in the rack, and STILL not be guaranteed of any particular sonic performance. You have to suck-it-and-see.

Let's face it. You build one, you learn something. You modify it, you learn even more. Personalise one, -hell, they're cheap enough! If you think Lundahl's are too clean (as I sometimes do) then whip them out and try something down-n-dirty, like OEP. Will they make your G1176 sound like a Revision D? -Never[/u][/b] in a million years! There's no tertiary winding feedback, no class-A discrete output stage, and active electronics before the input control. Will you like the sound? -Very likely. And if you don't,  there a re tons of people here who will trade transformers until everyone ends up with something that they're happy with.

But you simply can't say "the G1176 is less like a UREI than a Purple" or "the Purple is more like a Urei than a UA reissue"... You have to be quite specific.

And if you ever HAVE heard an 1176 and liked it? which one was it? Perhaps the Gyraf version will be exactly what you're looking for. -If however you're looking for deep, strong, rich sound under stiff compression and heavy GR, I rather suspect that -like the local studios who tried my Bloo/Purples- you really want the Rev D UREI, or the Purple.

The Purple has several significant advantages over the original UREI version: XLRs and other visible things are one small thing, but the fact that none of the two big transformers are mounted on the PCB is a HUGE reliability advantage... you might not think so unitl you drop one... I've had to repair more than a couple of snapped/cracked UREI PCBs in my time, and the Purple is just the same darned exact thing, but with better mechanical engineering, and transformers bolted to the CASE instead of the board. The Meter in the UREI is modutec and is reasonable, but the HOYT meter in the purple -while not my favourite meter- I do have to admit it's rather better than the modutec. Myself, I have now replaced my modutecs with Sifams inmy own units: the "swingy" modutec ballistic was making me dizzy!

Keith
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Rob Flinn on September 19, 2006, 06:38:37 AM
I was thinking about the class A output stage.  The biggest problem to DIY this is the tertiary feedback winding in the output transformer.  

I had the idea that perhaps it would be possible to use 2 output transformers instead, one for the audio out, & the other to provide the tertiary feedback.

Anyone have any thoughts on this or think of a reason why this wouldn't work ??
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 19, 2006, 07:14:47 AM
Wouldn't work, as the idea in the tert. winding is that it shares magnetic path - and thus distortion etc. with the main windings.

The sensible thing to do would be to talk someone like Edcor into making a decently-priced version of this transformer.

- hint-hint -  :wink:

Jakob E.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Rob Flinn on September 19, 2006, 08:08:35 AM
Do we know aht the characteristics of the transformer are ??
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 19, 2006, 08:19:54 AM
Should be possible to find out..

Mr Hacksaw - will you, please?  :razz:

Jakob E.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 19, 2006, 08:38:06 AM
hint?  :green:

of course we would need specs, then a lot is possible
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 19, 2006, 10:06:05 AM
Quote from: "tony dB"
hint?  :green:


Exactly..  :wink:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 19, 2006, 10:40:12 AM
are there mu cans involved?
We don't do those for the moment...
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 19, 2006, 11:09:25 AM
No cans. But there may or may not be gapped-core or ni-lams involved..
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 19, 2006, 11:52:47 AM
less of a problem then cans (little reserve, in case expectations not met)
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 19, 2006, 01:34:00 PM
edcor custom tert wound o/p tx's.  a noble idea if ever was one.  

the true noble deed will come from our saviour, who shall give forth his everlasting o/p tx to be crucified on the hacksaw to redeem all our fet squishing sins.

or maybe we're lucky and cj already knows the specs ;]

luckier still will be if it doesnt require any tricks that edcor doesnt do.

fingers crossed

billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 19, 2006, 01:49:48 PM
enter Hacksaw
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 19, 2006, 02:09:05 PM
i've had edcor do a number of custom designs, and i would guess that given some time, they could do a workable version of the class A 1176 OPT.  but here comes a delicate thing...  purple has spent some time/effort/money to figure out how to correctly wind these OPTs.  we sell them for $55ea now, and don't make much money on them that way.  i understand that as DIY-ers we're all "thrifty" and edcor could possibly make them a bit cheaper than our current supplier.  but then again, the guy making them for us is probably as close as you can get to the original winder.

so, send purple an email if you want to buy one from us.  if someone wants to organize a group buy from cinemag, the part number is PA96731.  at one point i also specified a version with both secondaries brought out seperately, the part number is CM96731-A.  i'm not sure you'll get a better price going direct, but you are welcome to try.

ed
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 19, 2006, 02:15:52 PM
also, the MC76 kit page (http://purpleaudio.com/Product/MC76kit.html) is going to be updated to include the ratio and meter switchbanks and caps, which are now included in the $300 price.  for a long time it was difficult to get them, so they weren't included, but now we have a reliable supplier.  meters are also available.

is there anything else (other than lowering the price) that we could do to make the kit better?

i personally would like it if DIYers would support a company that offers a kit version of one of their current products.

ed
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 19, 2006, 04:13:28 PM
Yay!!!

Hey look... I'm famous, on the purple MC76 kit page!!!

Keef
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: clintrubber on September 19, 2006, 04:56:25 PM
Quote from: "Rob Flinn"
I was thinking about the class A output stage.  The biggest problem to DIY this is the tertiary feedback winding in the output transformer.

Are such TXs that rare ?

FWIW, I pulled a board with audio TXs from an old Ampex video-tapemachine and found that
the output-TXs had a third winding for driving a meter
(no idea why that required an additional winding, but OK):

(http://home.hetnet.nl/~chickennerdpig/FILES/540/TX-out_sch_400.jpg)

(http://home.hetnet.nl/~chickennerdpig/FILES/540/TX-out_pic07_400.jpg)

But what's the story for output-circuits like that ? (class A & feedback with a tertiary winding)
How do they do 'their signature' ?! One would say they're actually more transparant, right ?

At least I assume that all that third winding trouble is to get higher fidelity
- so one would say that such a stage is then less contributing w.r.t. 'sound'.
Please tell  :roll:

Thanks / regards,

  Peter
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 19, 2006, 05:04:47 PM
ed, that just made that kit mucho better, in my opinion....  what are your prices on meters if you dont mind me asking 'in forum'?

thanks so much for the kit offer, its an excellent one.... i'd like to get into some soon as i can.  

quick q about the input attenuator... is it stepped or variable?

just curious about it.

thanks again

billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: khstudio on September 19, 2006, 05:57:40 PM
Quote from: "edanderson"
i've had edcor do a number of custom designs, and i would guess that given some time, they could do a workable version of the class A 1176 OPT.  but here comes a delicate thing...  purple has spent some time/effort/money to figure out how to correctly wind these OPTs.  we sell them for $55ea now, and don't make much money on them that way.  i understand that as DIY-ers we're all "thrifty" and edcor could possibly make them a bit cheaper than our current supplier.  but then again, the guy making them for us is probably as close as you can get to the original winder.

so, send purple an email if you want to buy one from us.  if someone wants to organize a group buy from cinemag, the part number is PA96731.  at one point i also specified a version with both secondaries brought out seperately, the part number is CM96731-A.  i'm not sure you'll get a better price going direct, but you are welcome to try.

ed


I have 2 of the G1176 (Mnats - new version) boards fully stuffed & ready to go... OEP's on the outputs, one w/IC in & one w/Lunduhl input.

I didn't realize your kits were priced so reasonable. Is it posible to MOD the output stage of my current G1176 board to the "Blackface - Purple - Class A circuit" & use your output trannys or is it too much of a PITA :?:

Also, I'm really confussed about the input "T  PAD's" & if they're needed in the "Silver face/G1176 clone" & for WHAT???

- is this something I should add to my G1176 & do you sell those too :?:

Thanks ED,
Kevin
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Infernal_Death on September 19, 2006, 06:21:29 PM
I am still interested in a purple kit somewhere down the road. Especially to complement the G1176. Just need to recover from a soundcard/converter buying spree  :green:
This kit really looks amazing.  :thumb:   :guinness:

Flo
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: eskimo on September 19, 2006, 07:07:31 PM
I've been really interested in the mc76, including the switches didn't make me any less. In fact, the trouble with that was kinda intimidating before.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 19, 2006, 08:12:26 PM
meter - $100
attenuator - $70

the attenuator is continuous (not stepped).  all of the urei revs with input transformers (A-F) used an attenuator before the input transformer.  the rev G and later versions used an opamp before a 10k pot, which is what the gyraf version does.  when you install the input transformer on a g1176, it goes before the pot.  if you were to put the pot first, the input impedance would not stay constant as you turn the pot, which is why you need a special attenuator if you want it before the transformer.

the output transformer is gapped, has a teritary winding AND a dc balance winding.  more common features in tube amp OPTs than solid state, from what i've seen.

i don't recommend trying to mod the gyraf or mnats boards to class A.  better to do it on a small piece of perf board.  or lay out a new board.  or buy the purple kit.

if it wasn't clear before, i work for purple audio, but andrew roberts runs the company and all purchase inquirys should be directed to him via email.

ed
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tommypiper on September 19, 2006, 11:37:39 PM
Ed, glad to see you in the discussion.  A purple kit is in my future, I hope.

Just wanted to also mention there is another 1176 kit and PCBs available from Eddie Ciletti and Scott Liebert.  It's got Neve-ish class A guts, running at higher voltage and looks very interesting.  You can even add a mic pre to it to take advantage of the Neve-ish circuit.  We've just been discussing it over in the Brewery.  Check there for more info under the Ciletti thread. http://www.groupdiy.com/index.php?topic=18106&start=15&sid=84e9d5bd4de7803db4cf599409db4aaf
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: mnats on September 20, 2006, 05:29:04 PM
I agree with Ed - it's not practical to mod the Gyraf or my board to the class A version. But it would be possible to do a new revision to the output amp section of my version of the G1176 for the group - but only if it doesn't upset anyone to do it. Might make putting two channels in one 2U case practical too, which seems to be the direction a lot of people are going with the rotary switch option...
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: imo on September 20, 2006, 06:36:45 PM
I have made the Eddie Cilleti "1176". I love it. It has an open top end that is really useful and i find myself going to it quite often over either of my other 76's or my Distressor, especially with vocals, etc.
They were very helpful as well
Ian

I personally would love to look into some of the changes that Mnats is talking about
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: mfdu on September 20, 2006, 10:33:13 PM
i've got two g1176's with ic in, OEP out, and two with OEP in and out.

(http://home.alphalink.com.au/~mfdu/images/background_diy.jpg)
(the silver face is the OEP i/o, the black unit is the ic in, with slam mode dpdt.  the top unit is a dual what? opto)

i have no idea what a true 1176 is supposed to sound like.  but do i think it actually matters?  hmmm.  no(?)
each of my units has a different character, due to differences in capacitors etc, and that's the way i like it.  each unit has a different use, and fits a different purpose.

but i understand that is totally ignoring physical differences in board design.

so i ain't really much help.

chris.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tommypiper on September 20, 2006, 11:52:02 PM
imo, what iron are you using in your Eddie/Scott Neve 1176?

I love Vashon Island, btw.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: khstudio on September 21, 2006, 01:18:50 AM
Quote from: "mfdu"
i've got two g1176's with ic in, OEP out, and two with OEP in and out.

(the silver face is the OEP i/o, the black unit is the ic in, with slam mode dpdt.  the top unit is a dual what? opto)

i have no idea what a true 1176 is supposed to sound like.  but do i think it actually matters?  hmmm.  no(?)
each of my units has a different character, due to differences in capacitors etc, and that's the way i like it.  each unit has a different use, and fits a different purpose.

but i understand that is totally ignoring physical differences in board design.

so i ain't really much help.

chris.


I like hearing other opinions about the tranny/sound differences... it helps get an idea what to expect -  especially when you can make "sound" comparisons to units like the DISTRESSOR... they're pretty comon & consistant sounding.

Kevin
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 21, 2006, 02:06:01 AM
see...  i'm tellin ya, its the stuff that is new/hybrid, etc, that is the coolest thing around...  nothings 'new,'  i know i know, sometimes, but hey, its all a bunch of legos right?

we're just big kids with legos, come on.

some of us can build the ferris wheel, some of us the starship cruiser, and some of us cant get the two flat pieces apart.  so we add a third, and it equals a normal lego.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 21, 2006, 02:51:32 AM
Quote


I like hearing other opinions about the tranny/sound differences... it helps get an idea what to expect -  especially when you can make "sound" comparisons to units like the DISTRESSOR... they're pretty comon & consistant sounding.

Kevin


Distressors are transformer less. Just one of te reason's they appear cleaner then some other designs. Circuitry of the Distressor is derived from the 1176. Mine have the British mode option, what mimics the effect you get when pushing all for ratio buttons at once on early 1176's. It's not the same, but very usefull when applied to the right sounds.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 21, 2006, 07:28:55 AM
I am seriously considering a Purple MC77 for my next DIY. Can someone tell me how difficult it is to DIY the MC77 with KIT option on the scale of 10 if the G-SSL is on level 4?

Also does anyone know How much in parts does it cost beside the 300$ for the KIT. I will use my own 1176 case so minus the cost for the case.

Another thing, Keith you mentioned there is some tweaking needed for the 1176. Can you be more specific about it? Isn't this more or less just a plug and play DIY like G-SSL?
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 21, 2006, 07:31:55 AM
There's meter zero (easy), bias (easy), meter tracking (some patience needed) and that's about it... -I can't remember if there's a distortion trip or not, but I suspect not... the FET feedback is fixed, so shouldn't be too tough.

Keith
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 21, 2006, 07:52:57 AM
Thanks Keith  :thumb:

What about the approximate additional cost for the parts beside the MC77 KIT and case?

Another thing which is very important to me  :shock: do I need to go with push buttons for the MC77 DIY or can it be done like on the G 1176?
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: smallbutfine on September 21, 2006, 08:31:50 AM
Purusha,
the additional costs to the Purple kit are not easy to say as it is very dependend on what you WANT to add... For you, the case may not be the problem :wink:  but you have to consider that caps can be of very different quality and prices (say Elna Starget NOS or Nichicon or Panasonic or NoName...with prices that differ from cents to dollars! ) as is for the transistors (original NOS, used or modern xreferences) or even the resistors (there are audiophile resistors out there that cost ten times as much as standard 1% metal film-... :shock: ). So it is for the switches - it is easy to raise the price to a multiple if you go with Elma or Grayhill instead of that cheapy plastics we all use a lot... :grin:
So i really do not get the point in the question you repeated, really...
If i would say: Go for the best quality with little compromise and invest e.g. another 300$ in the rest of the parts, trying to be authentic with the transistors and neutral with the elyts and use 1%Metal film res thruout, while doing your own case (that look very fine IMO)...would that answer your question for a recommendation?
 :?:

Kind regards,

Martin

PS: there should be no problem at all to wire the purple kit with rotaries instead of switch banks....
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 21, 2006, 09:01:29 AM
Quote
So it is for the switches - it is easy to raise the price to a multiple if you go with Elma or Grayhill instead of that cheapy plastics we all use a lot... Very Happy


There are only two switches needed if I am right so this can't be a lot more expensive even if I take the Elma or Grayhill. I don't know about how many caps go into one MC77 but I can order some Nichicons or Rubycons for this. Regarding the resistors I'll stay with 1% metal. OK, so in all I could get away with 600$ or less. Thanks for the info.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: smallbutfine on September 21, 2006, 10:08:36 AM
Quote
There are only two switches needed if I am right so this can't be a lot more expensive even if I take the Elma or Grayhill.

I just spoke for the switches not for the unit ('raising to a multiple'), sorry i did not make that clear.

:grin: Yes, i think so. I calculated this amount (~ 600$) for myself some time ago - and decided to let this project have a break until i can afford a dual mono version 'out of the pocket' later.... :wink:

Kind regards,
 :thumb:
Martin[/quote]
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: tony dB on September 21, 2006, 11:18:20 AM
my diy 1176 uses Lorlin switches instead of pushbuttons.
Lorlins can be had for as little as 1 - 1,5 euro.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 21, 2006, 11:37:49 AM
Does anyone have some nice shopping parts list somewhere for the MC77 DIY? Keith maybe?

I just ordered the KIT  :wink:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: imo on September 21, 2006, 02:21:54 PM
Tommy,
I used a Cinemag on input, Sowter on output. Love the sound..
Vashon is a fortuitous place to live. Nice and slow, but close enough to Seattle to be able to pop in. Getting more crowded by the moment though.
Ian
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 21, 2006, 08:09:46 PM
more information about the mc76 kit, including the parts list PDF that we provide, can be seen at:

http://purpleaudio.com/Product/MC76kit.html

ed
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 21, 2006, 09:45:47 PM
Quote from: "edanderson"
also, the MC76 kit page (http://purpleaudio.com/Product/MC76kit.html) is going to be updated to include the ratio and meter switchbanks and caps, which are now included in the $300 price.
\


cant beat it at that point


billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gevermil on September 21, 2006, 09:54:48 PM
Is that Custom line input transformer a replica of the 0-12 utc or is it something else . I have a quite a few 0-12's  and wouldnt mind attemting a purple kit .
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 22, 2006, 12:09:33 AM
Quote
Is that Custom line input transformer a replica of the 0-12 utc


yes.  see the MC77 parts page for more info on the parts, SOME of which are included in the kit.

http://purpleaudio.com/Product/MC77part.html

ed
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 22, 2006, 02:57:09 AM
edanderson, PM'd you  :wink:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 22, 2006, 03:29:27 AM
was reading about this B11148, whatever i could anyway, and it seems i have some nickel 625ei around, .65" stack as ed mentioned in another thread...... turns ratio is 1+1:3.5+3.5, although somewhere else i thought i read 4 identical windings?

in pictures i've seen of 1109's it looks an awful lot like a 4804, being cardmounted in that case.

anyway, just wondering if anyone knows anything about wire gauge for these guys, or can confirm 1+1:3.5+3.5

wouldn't mind trying it in my g1176, go for a true g unit, or something.

or maybe some la3 or 1109 foolishness ;]

billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 22, 2006, 05:17:06 AM
Are you sure that it's a nickel core for the output transformer? At the mentioned price, I'd doubt that - but I may be wrong.

On the other hand, the transformer (carrying some DC current, but in a pseudo-outbalanced manner) may or may not be air-gapped core - try checking that out as well..

From the old schematic drawings it looks like the transformer has five windings in four groups - a total of 10 wires comes out - but this might not be important.

Can't help you with the turns ratios - though I'd be very interested in knowing this too, if anyone has access to that info!

Jakob E.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Family Hoof on September 22, 2006, 09:03:21 AM
I had an 1109 output transformer on the bench a few weeks ago and it was most definitely EI625 steel of some sort, not nickel. Also, I got more than 14dB step-up by wiring it series:parallel, so the 1+1:3.5+3.5 ratio would make sense. Only 8 wires, in the same colors as an AP2503.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: gyraf on September 22, 2006, 09:29:28 AM
Yep - but the 1109 lineamp is like the later push-pull class-AB 1176's - not "blackface class-a"

Jakob E.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Family Hoof on September 22, 2006, 09:33:46 AM
Quote from: "gyraf"
Yep - but the 1109 lineamp is like the later push-pull class-AB 1176's - not "blackface class-a"

Jakob E.

Yes, I know. Did someone say otherwise?
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: SSLtech on September 22, 2006, 09:47:38 AM
Quote from: "Family Hoof"
Quote from: "gyraf"
Yep - but the 1109 lineamp is like the later push-pull class-AB 1176's - not "blackface class-a"

Jakob E.

Yes, I know. Did someone say otherwise?

I think that in such close proximity to the Purple Audio kit information, it's a very wise idea to be prefectly clear at all times...

Specially since I dragged the whole thread (back on page 1) into a direction where I opined that it's vital to be very specific about WHICH revision 1176 in all of these discussions...

 :thumb:
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: edanderson on September 22, 2006, 12:04:04 PM
to throw some more information into an already fragmented thread...

if billy (enthalpystudios) or anyone else wants to try to wind their own 1:3.5 OPT for the g1176, here's a simplified version of the b11148:

the core is 46 pieces of 29ga M6 steel, interleaved (no gap) in a 0.625" square stack.

the winding structure is:

1/2 secondary
primary
1/2 secondary

first wind 475 turns of 30ga.  the beginning is the start of your secondary, the end gets spliced to the beginning of the other half of the secondary.
wind on a layer of mylar insulation
next wind on 270 turns of 26ga.  the beginning is the start of your primary, the end is the finish of your primary.
another layer of insulation
finally, another 475 turns of 30ga.  the beginning connects to the end of the first winding, and the end is the finish of your secondary.

that's it.  try to wind as neatly as possible, or wind very tight randomly, and it should all fit.

have a look at the DIY API output winding threads for details on labelling, bringing out leads, etc.

another good option for a 1:3.5 output is the marinair LO2567 with pri in parallel, sec in series.  cj has posted the winding infos.

i'd like to make some full blown b11148 transformers available for purchase some time soon.  but there are some other projects in the pipe first.

ed

edit: mixup in the turns numbers
edit again: mixup in the wire gage
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 22, 2006, 12:48:21 PM
wow ed, thanks so much for that.

only reason i said anything about nickel is because it's what i've got....  I'll try it with that and see how it works, and if winding trannies doesnt blow up in my face than i'll order some m6.

winding transformers is definitely not something worth doing to "save a buck"

its definitely something that is worth doing if you're just into trying it all out to see how it all works.

i was just relieved to see another solid transformer, for which i have an immediate use, that could be wound on the lams i have in my boxes of stuff

so thanks again guys!  awesome stuff.  

billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 22, 2006, 12:50:27 PM
also, sorry for getting off topic....   especially as my post had everything to do with revG 1176.  and 1109 and la3a as well.

billy
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: Purusha on September 22, 2006, 03:28:46 PM
A quick question : can I use Sifam AL-29WF Meter instead of the Hoyt meter with MC77 KIT?

I just noticed that they are different in size and I would have to make a new front panel for the MC77 if I go with Hoyt.
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: enthalpystudios on September 22, 2006, 06:02:06 PM
the sifam will work great.

i have some MCI (dixson or triplett, not sure) vu meters in my g1176's, they work great
Title: G 1176 vs PURPLE AUDIO MC76 vs UREI 1176
Post by: hitchhiker on October 22, 2006, 12:41:09 PM
I had an eye on the Purple MC76 kit for a long time . After reading this thread I just had to order. It arrived this week and I am very impressed!
If it included the 1n4936 diodes (what are they?)and those various mega ohm 1/2 watts I would of been able to build right away. So close! Anyway, this kit is a great deal!