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Project Specific Discussions => Dynamic Processors => Topic started by: dandeurloo on July 02, 2011, 10:58:54 PM

Title: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 02, 2011, 10:58:54 PM
Hey Guys as a proud owner of a few stuffed Mnats rev. d's and a Hairball kit and a few cases (I know, I know) I am close to wrapping up my 1176's.  I read through the massive Mnats Rev. D help thread and notice some of that info is old and much of it is about strictly older revisions of Mnat boards which have now been updates.  Also not all of it applies to the specifics of the Stereo 1176's and it seems to be starting to get confusing meshing the wiring of the stereo 1176 with the mono units.  So, I was hoping to start a new thread dedicated to the Stereo versions.   

The other thread should still keep alive and well because it has great info in it and specifics of wiring up Hairballs kits in his excellent cases.  Hopefully this will help keep info more organized and clear.

I will do the best I can to keep this first thread up to date with the current and accurate help notes in case it becomes an 85 page help thread guys can find info a little quicker!

Ok, the things that could be helpful from any of you would be wiring diagrams and photos of how you have had successful layouts of the boards in the chassis. 

Thanks guys!


Helpful Links:
Rotary Switch Wiring - (http://mnats.net/1176-wiring-rotary.html (http://mnats.net/1176-wiring-rotary.html))
Slam Mode Switch Wiring - (http://mnats.net/1176_slam_mode_rotary.html (http://mnats.net/1176_slam_mode_rotary.html))
Calibration Videos - (http://mnats.net/1176_revision_d.html#videos (http://mnats.net/1176_revision_d.html#videos))
Stereo Link Boards Wiring - (http://hairballaudio.com/guides/Stereo_Link_Wiring_Guide.pdf (http://hairballaudio.com/guides/Stereo_Link_Wiring_Guide.pdf))
Stereo Link Boards Wiring - (http://www.wuala.com/ricothetroll/public/Stereo-Link_wiring.gif (http://www.wuala.com/ricothetroll/public/Stereo-Link_wiring.gif))
Stereo Link Boards Help thread - (http://www.groupdiy.com/index.php?topic=35656.0 (http://www.groupdiy.com/index.php?topic=35656.0))
BOM for Mnats PSU - (http://mnats.net/psu.html (http://mnats.net/psu.html))


R12 for Rev D ( http://www.groupdiy.com/index.php?topic=44909.0 (http://www.groupdiy.com/index.php?topic=44909.0))
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 05, 2011, 09:43:29 PM
I'm also finding this link from the mnats site useful: http://mnats.net/1176-wiring-rotary.html
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 05, 2011, 09:53:09 PM
Got it!  Thanks Dash
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 05, 2011, 10:06:23 PM
Edit: Incorrect information posted
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 08, 2011, 10:11:34 AM
Dash can you confirm this once you get a little further.  I'm hopefully gonna get to work on mine a little this weekend.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 08, 2011, 11:01:21 AM
I have a couple of questions about the Master bypass/Comp control

How should this be connected? Does it not duplicate the function of the GR OFF position of the meter switch? Is it just a case of wiring pad 22 on the main PCB through the switch so that it connects to ground in the off position and connects to Pad 22 on the meter switch board when on?



Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 09, 2011, 03:07:19 AM
Dash The master Bypass requires another true bypass board.  Marc has some that I think will work and so does Igor.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 09, 2011, 03:24:25 AM
Questions about wiring up the Stereo Link boards.

1. Should the ground go to the main boards or back to star ground for the least amount of noise?
2. Do I wire a lead from both boards ("link" pads) to the link switch?  Or is it just one wire from board #1 to the link switch?
3. On the ratio boards are the "OUT PUT" sections to be tied together or left empty.  The diagram from this link is slightly confusing. http://www.wuala.com/ricothetroll/public/Stereo-Link_wiring.gif
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: KasperNyhus on July 10, 2011, 01:27:30 PM
Hi Guys

I'm also confused about this stereo link board wiring... Hooked it up as shown in the drawings but I never got it to work properly...

When Dual mode is flipped on channel 1 fully attenuates the signal and comes back again after some seconds. Also the input has to be much higher in dual mode to get the same amount of compression compared to mono mode. And finally the two channels doesn't affect each other - thats a bad stereo link then...  ;D

If there is someone who has made this work I would be very happy to see the wiring!!

I will follow this thread...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 11, 2011, 10:02:23 AM
Dan - I would take the ground from the link boards back to the Star Ground. I also think you should wire both boards to a DPDT switch.

I've left the 'output' sections on the ratio boards empty.

I've finished mine and it seems to be working fairly nicely on dual mono mode. I have one issue when I use it in Slam mode. In this mode the meter works fine on the +4 setting, but when I move it to show GR the meter goes hard right. It responds to the input - so it shows gain reduction, it just seems to go hard right whenever it returns to zero. The meter shows GR correctly in all other ratio settings. Any ideas? Is this expected behavior.....? I've got a feeling it might be....

Also - not quite sure how to verify that link mode is working correctly. When I engage it only one channel seems to be working and it the amount it is compressing reduces significantly. The GR meter on the other channel is unresponsive.

Also, I find moving the release affects the meter GR display by 3-4db. I've read somewhere this might be due to the diodes used in the circuit. Does anyone have any more info?


Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 11, 2011, 11:46:43 AM
hmm.  interesting.  At least you are making some good forward progress!  I am not sure if it would matter if it is a dpdt or a spdt switch?  I think either way they do the same thing in this case.  Am I wrong there?

I'm no help as of yet on the Meter question you are still a head of me.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 11, 2011, 07:51:42 PM
Am pretty sure you want DPDT rather than SPDT. You don't want to be summing the sidechains at the switch - you should leave that to the Link boards so the sidechain should be isolated until it gets there.

Think of it as the wiring image you link in the first post only showing one side of the switch. You need double throw as you either want the sidechain connected directly to the ratio board OR to the link board. The bottom line is that it needs to be connected to something

Thats the way I see it anyway. By no means an expert.....
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 11, 2011, 10:33:18 PM
Ok, that makes sense.  I knew they would get summed together but I guess that is what the boards are for!

Also to confirm something.  The .022uf and 470 resister for the attack pot and the 270k resistor for the release pot are all on the ratio boards for the rotary versions correct.  So no need to do those on the pots.

I'm slowly picking through this. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 11, 2011, 10:53:35 PM
Yup. On the ratio boards
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on July 12, 2011, 02:18:40 AM
Questions about wiring up the Stereo Link boards.

1. Should the ground go to the main boards or back to star ground for the least amount of noise?
2. Do I wire a lead from both boards ("link" pads) to the link switch?  Or is it just one wire from board #1 to the link switch?
3. On the ratio boards are the "OUT PUT" sections to be tied together or left empty.  The diagram from this link is slightly confusing. http://www.wuala.com/ricothetroll/public/Stereo-Link_wiring.gif

1.  See here http://www.groupdiy.com/index.php?topic=35656.msg481187#msg481187 looks like the start ground is a better option.
2. Both to the switch (DPDT) if I understand you correctly.
3. Output just connects to 15 16 17.  I don't have a ratio rotary board here but I think you can ignore those pads.

Good luck!

Mike

edit:  Now I see dashbad answered this already ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on July 12, 2011, 02:20:28 AM
Hi Guys

I'm also confused about this stereo link board wiring... Hooked it up as shown in the drawings but I never got it to work properly...

When Dual mode is flipped on channel 1 fully attenuates the signal and comes back again after some seconds. Also the input has to be much higher in dual mode to get the same amount of compression compared to mono mode. And finally the two channels doesn't affect each other - thats a bad stereo link then...  ;D

If there is someone who has made this work I would be very happy to see the wiring!!

I will follow this thread...

Check the stereo link thread.  There is some discussion about the stereo link hook up in a rotary build.

Mike
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on July 12, 2011, 02:25:28 AM
Also - not quite sure how to verify that link mode is working correctly. When I engage it only one channel seems to be working and it the amount it is compressing reduces significantly. The GR meter on the other channel is unresponsive.
Remember for this stereo link method, all settings should be identical.  If you are feeding a signal into each channel that are relatively the same, you can tweek the output and input to adjust for variances in components between units.  Once they are compressing identical, if one side gets an additional tone burst, both meters should react the same.

Mike
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 12, 2011, 04:19:46 AM
Thanks Mike,

I'm using matched FETs from yourself. Can you confirm - are all 4 FETs matched so I can use any of them in either unit in either position or do I need make sure 1 pair is used in one channel and the other pair in the other channel?

If the latter, what effect would this have on the unit?

I've also added a question to the stereo link support thread as Ive narrowed down my issue there.

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on July 12, 2011, 10:12:28 AM
I would keep the pair together.  The FETS in one pair are matched within 10% (usually 1-3%) along the full curve.  The pairs themselves all fit within an overall curve.  It probably wouldn't matter too much if you mixed them all up but it may make your meter somewhat off.

Even if two pairs are at opposite ends of the acceptable range, they should be close enough to keep you within 1db of stereo operation down to 10 db of gain.  You may need to adjust the in/out to get the channels matched.

Mike
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on July 12, 2011, 06:52:17 PM
Some people also get confused about the extra power supply board too. the info is here:

http://mnats.net/psu.html (http://mnats.net/psu.html)

John
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on July 12, 2011, 06:58:36 PM
If you are using pro tools... Or another daw. Get the stereo compressor sounding good by ear. Then send a sine wave into both channels at the same level. And tweak each channel. I rarely do this tho. I find it is always close enough for horse shoes and hand grenades..... ;)

John
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dashbad on July 19, 2011, 10:03:28 AM
I've finally finished my stereo unit. Having spent days trying to work out why the stereo link wasn't working, including changing the switch and numerous components I found out that I was using an incorrect opamp on the link pcb. DOH! It's always the stupid errors that have you stumped.

Anyway, I'm pretty chuffed with the unit. It sounds great and was great fun to build. Many thanks go to hairball, mnats and Dan for providing all the parts and case. For what its worth I've posted some pics below.

My wiring is, to say the least, a bit of a joke - so perhaps this is more of an advertisment on how not to lay out a 1176-2  ::)

I did my best to try and keep the audio path out of the way of the power and managed to do this however it was never going to be easy with the power switch located in the centre of the unit. That said, I'm very happy with how quiet it is. Under normal operation it's basically noise free and I only get -56dbfs of hiss in my DAW if I crank the input and output to Max with no signal. Pretty good imo

For the front panel lamp I used a 240V xenon panel indicator from RS Components and wired it in parallel with the mains supply and power switch. Its not the greatest quality and maybe something I'd change if I could be bothered. If I could redesign the case I would definitely move the power switch and lamp over to the right hand side of the panel as this would help with wiring a great deal.

Ok, here are the pics. Please be gentle - as I say, I realise my wiring leaves a fair bit to be desired....

(http://dl.dropbox.com/u/1462564/DSC00059.jpg)
(http://dl.dropbox.com/u/1462564/IMG_5662.jpg)
(http://dl.dropbox.com/u/1462564/IMG_5667.jpg)
(http://dl.dropbox.com/u/1462564/IMG_5668.jpg)
(http://dl.dropbox.com/u/1462564/IMG_5670.jpg)



Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: waner on July 28, 2011, 08:46:53 AM
Hi

I`m about to start on my Stereo 1176 (with Dan`s great case and Hairball`s stereokit). I wonder if someone have figured out a good layout for the PCB`s in the cases. I`m worried about Hum with the powerswitch at the center of the case.

Thanks
Mattias
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 28, 2011, 10:27:33 AM
I think I have a ok layout going on.  Transformers all on the side walls. Input and outputs on the opposite sides from the IEC inlet.  PSU transformer on the right side between the IEC inlet and the side wall towards the back.

The put the PCB's toward the input and output transformers.  I haven't had time to complete mine yet but it seems to keep audio away from the PSU power.  If I get a chance I will try and put pics up.  I've been slammed with producing and mixing.  Hopefully next week I'll have time to try and finish it.  I also have the hard bypass boards that I need to figure out where to put them..could get tricky.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mitsos on July 28, 2011, 11:21:22 AM
I am thinking of doing mine like the UA 2-1176:  PSU in the middle, each channel off to one side.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: waner on August 03, 2011, 06:59:18 AM
So this is the layout I`m going for.

I mounted the mainboards on 40mm tall hex and put the Inputtransformer and stereo link board underneath.
The inputciruit is far away from the maintransformer and the cables to the Powerswitch can go on the bottom of the case.

Just some wirring left
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on August 09, 2011, 10:22:25 PM
Hey guys, anyone know does it matter which way the Lorlin switch goes on to the meter board?  I think it probably doesn't matter as long as I make sure the stop pin is on 3.  Can anyone confirm before I solder these in?  Thanks
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on October 19, 2011, 03:26:22 PM
Does anyone have a confirmed working Stereo Link board.  I have tried a few different ways of wiring it up and its not working properly yet.  Any ideas would be great. 

Everything else on the unit seem to work great and sound really really nice!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: benlindell on October 19, 2011, 04:21:21 PM
Does anyone have a confirmed working Stereo Link board.  I have tried a few different ways of wiring it up and its not working properly yet.  Any ideas would be great. 

Everything else on the unit seem to work great and sound really really nice!
+1 mine never worked right
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on November 22, 2011, 10:09:58 AM
is there an official mouser list for the power supply pcb?

also, do I really have to do the rotary switch thing? I wanted to do my clone with the classic button option and bought these in addition to the stereo kit.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on November 22, 2011, 10:35:19 AM
yeah, the push buttons don't work in the chassis.   To big for the stereo units.

Mnats has a bom on his site for the PSU. Here it is.  I'll link on the main page as well.
http://mnats.net/psu.html
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: abechap024 on November 22, 2011, 10:52:39 AM
I just built 2 of these units. I ran into a ton of problems most of them relating back to the single sided PCB boards from Mnats having broken traces on them, right around were I soldered in components (don't know if they were old boards or what) Maybe I don't solder gently enough :o?
But in any rate, I was having trouble with the stereo link, till I stupidly realized I thought both opamps were tlo71 for some reason and one was actually tlo72, also don't forget to install that wire jumper on the pcbs.

Then in practice you have to sometimes adjust the attach and release for them to be more "in stereo" as the only thing the stereo link boards does is send the same audio to the side-chains, but in reality slight differences in timing cap value, timing resistor value, attach/release potentiometer tolerance (usually +/-20%) means you have to adjust input/output and most importantly attach/release by ear and by meters for them to track reasonably well. thats been my experience at least.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on November 22, 2011, 01:12:23 PM
yeah, the push buttons don't work in the chassis.   To big for the stereo units.

Mnats has a bom on his site for the PSU. Here it is.  I'll link on the main page as well.
http://mnats.net/psu.html

thanks but isn't there a mouser list?

I have a hard time finding the components or rather settle with the right one.

Then there is also the question whether I have to still stuff the power section of the original pcb?

I mean anything that's on the picture of mnat's psu site is for an older gyraf unit or so. Doesn't help me at all.

Should've bought two power transformers and power them separately instead of doing this temporary stereo solution...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on November 22, 2011, 01:34:57 PM
No need to stuff each PCB if you use the Dual PSU board.  That's the reason to use it!

No mouser cart that I know of.  You just need standard parts for it so stick with the same types you see in the rest of the Mouser cart.  Just get the right values. 

Pretty easy just takes a little time to sort through it you first go round.

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on November 22, 2011, 02:35:35 PM
No need to stuff each PCB if you use the Dual PSU board.  That's the reason to use it!

No mouser cart that I know of.  You just need standard parts for it so stick with the same types you see in the rest of the Mouser cart.  Just get the right values. 

Pretty easy just takes a little time to sort through it you first go round.

yeah just took some regular ones.

well I don't have to meaning that I could practically stuff both boards and power them with the supply?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mnats on November 22, 2011, 02:52:22 PM
I ran into a ton of problems most of them relating back to the single sided PCB boards from Mnats having broken traces on them, right around were I soldered in components (don't know if they were old boards or what) Maybe I don't solder gently enough :o?

I designed the boards, but I have never sold them. So the boards you have cannot be "from" me.

That said, I received two boards from the first batch done for Hairball and had no problems with broken traces. I think you're right - you may need better soldering practices. Can you post a picture?

well I don't have to meaning that I could practically stuff both boards and power them with the supply?

On my Rev A, D and F/G boards there is an outline around the power supply components (which can be left off if using a separate power supply) and a screen layer legend marking where the +30 and -10 Volt rails are connected. Grounds from each board are connected as per the wiring guide and tied to a common point on the chassis. If this seems unclear please don't attempt the AC wiring without help!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on November 22, 2011, 04:04:05 PM
I ran into a ton of problems most of them relating back to the single sided PCB boards from Mnats having broken traces on them, right around were I soldered in components (don't know if they were old boards or what) Maybe I don't solder gently enough :o?

I designed the boards, but I have never sold them. So the boards you have cannot be "from" me.

That said, I received two boards from the first batch done for Hairball and had no problems with broken traces. I think you're right - you may need better soldering practices. Can you post a picture?

well I don't have to meaning that I could practically stuff both boards and power them with the supply?

On my Rev A, D and F/G boards there is an outline around the power supply components (which can be left off if using a separate power supply) and a screen layer legend marking where the +30 and -10 Volt rails are connected. Grounds from each board are connected as per the wiring guide and tied to a common point on the chassis. If this seems unclear please don't attempt the AC wiring without help!

But the board is required to power two units with one transformer? So I can't stuff both boards and dual wire them?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mnats on November 22, 2011, 05:03:14 PM
But the board is required to power two units with one transformer? So I can't stuff both boards and dual wire them?

The separate power supply is not required, but suggested to reduce component count. You can still power two boards each stuffed with power supply components from a single transformer.

You can see an example of a stereo unit wired with the separate power supply board in the photos posted on Reply #21 above.

Please take note of my AC warning above. I believe that many people just ignore the warnings on my page.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: abechap024 on November 23, 2011, 01:41:58 PM
I ran into a ton of problems most of them relating back to the single sided PCB boards from Mnats having broken traces on them, right around were I soldered in components (don't know if they were old boards or what) Maybe I don't solder gently enough :o?

I designed the boards, but I have never sold them. So the boards you have cannot be "from" me.

That said, I received two boards from the first batch done for Hairball and had no problems with broken traces. I think you're right - you may need better soldering practices. Can you post a picture?


Single Sided PCB?  I'm talking about the 1176 boards Rev J I believe. The units are already racked up and I fixed the broken traces around components. Not trying to diss anything, The boards are really great, well laid out and everything. I just should've gotten some of your double sided boards with the plated through holes. The boards obviously didn't come with broken traces, just during the course of soldering all the components there were a hairline fracture our two around the solder point and then the trace. Anyway happened a bit on both my boards. Probably just my lack of soldering finesse.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mnats on November 23, 2011, 02:14:49 PM
Single Sided PCB?  I'm talking about the 1176 boards Rev J I believe.

Sorry, I thought that since you mentioned the stereo link boards just after you mentioned single sided that you were referring to the link boards themselves.

Of course I do sell the 1176 Rev J boards. But I've never heard of broken traces happening due to soldering. The solder mask seems to act as an extra layer of protection that keeps the tracks from lifting. But if you lift the pad itself then naturally it can cause problems where it joins to the track.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on November 23, 2011, 08:39:30 PM
But the board is required to power two units with one transformer? So I can't stuff both boards and dual wire them?

The separate power supply is not required, but suggested to reduce component count. You can still power two boards each stuffed with power supply components from a single transformer.

You can see an example of a stereo unit wired with the separate power supply board in the photos posted on Reply #21 above.

Please take note of my AC warning above. I believe that many people just ignore the warnings on my page.

Thanks.

So, if we are talking performance / quality / issues, depending on what you'd emphasis, which approach would you suggest?

I don't mind stuffing both power sections because I already bought the components two times.

But if the separate power board will give you a better performance / safer run, of course I'd chose this than instead of stuffing both boards.

Or were you referring to an interference issue when having both sides stuffed?

Mike
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: atticmike on December 03, 2011, 04:59:17 PM
Can anybody answer my question?

I'd really appreciate a little help on this decision.

Can't finish my unit until I've sorted out that problem :D
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: abechap024 on December 03, 2011, 06:52:04 PM
Can anybody answer my question?

I'd really appreciate a little help on this decision.

Can't finish my unit until I've sorted out that problem :D

You might get better sonic results because the power supply is off the board. Depends on a lot of factors though. I would just do whatever is easier for you. Both are going to work just fine. IMHO
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on December 22, 2011, 03:31:46 PM
Ok, anyone having problems with the Stereo Link boards read this.

DOUBLE/TRIPLE check your IC's.  I swore I had mine in the correct way.  Then Abe told me he got his to work but he first had his IC's in backwards.  So I double checked and I thought I had them correct.  Then I let it sit for a few weeks and came back to it a decided to TRIPLE check.  Sure enough I had them in the wrong spots.  I bet this has happened more then the 2 time to Abe and myself.  The IC's are labeled in a way that once you put sockets in you may take a quick look and think you are looking at the IC type and see a ***1 or a ***2.  But that is the IC # in the design not the actual TL071.  So the moral is make sure you really look hard and confirm it.

Question:
I now have them working and passing audio once the Link is in.  The they seem to be acting the same with a signal gen and changing the ratio's.  The only thing I have going on is my Left meter doesn't show reduction when switched to GR.  It does show +4 the same as the R channel when linked.  Any thoughts.

Everything works great when not linked. 

Overall this thing sounds really really cool.  Very Rock and Roll.  Thanks Mnats and Hairball and Abe for keeping going the right direction to get this completed. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: abechap024 on December 23, 2011, 12:44:17 PM

Question:
I now have them working and passing audio once the Link is in.  The they seem to be acting the same with a signal gen and changing the ratio's.  The only thing I have going on is my Left meter doesn't show reduction when switched to GR.  It does show +4 the same as the R channel when linked.  Any thoughts.


Are you sure the left channel is compressing? Is the problem limited to just the meter?
Glad to hear you are getting it worked out!

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: g fin on December 25, 2011, 07:02:02 PM
Hi all!

(I've already post this on the Lab's main page, I think it's better here. If any moderator can erase the one on the main page?)

I've just finished my Dual G1176 with Mnats PSU. I've already built a fully-working  single unit with the inboard PSU.

My problem is: Unloaded, the PSU give me on the first rail: -10V and +30V on the second, as needed.
When loaded (with any of my two main boards), the -10V remain, but the +30V drop to +5v. The LM317 is becoming very hot.
I observe the same with or without IC's and transistors.

My first question is: With Mnats PSU, do I need to stuff the board with IC's and transistors to get the good PSU voltage (when loaded)?

My second is: I re-checked severall times  the resistors values and the caps orientation on the main board. How could I pursue? Since both boards are faulty and stuffed together, it's probably more a bad component than a short...

Thanks for your help.

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on December 26, 2011, 09:54:28 PM

Are you sure the left channel is compressing? Is the problem limited to just the meter?
Glad to hear you are getting it worked out!
[/quote]

Well, I am pretty sure the left channel is compressing.  It is for sure when they aren't linked.  I think it is working when linked just not showing the GR on the meter?  Thoughts?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: g fin on December 31, 2011, 06:34:34 AM
Up.

Please!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: g fin on December 31, 2011, 07:43:20 AM
Could it be my transfo? It's a 2x22V 30VA, which is by the way perfect for a single unit with inboards PSU, but maybe not for Mnats PSU...

Another remark: when I plug the PSU to both boards, the +30V drop to nearly OV... :-[
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: g fin on December 31, 2011, 10:20:56 AM
It's not  :-[

Just bought a 2x25V 30VA: Same problem.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: g fin on December 31, 2011, 02:58:59 PM
I think I found by myself!

I didn't notice this detail on Mnat's boards: they're not configured for using  BD517 and BD518 contrary to Gyraf's one.

Will add jumpers on the board, and reverse them to get the right pin out.

Good point: I'm triple sure of my resistances and capacitors values!

So confused! :-[
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: kante1603 on December 31, 2011, 04:45:35 PM
Hi,

don't know this piece,but if a voltage drops down to 0v when you plug something in there must be short somewhere.
Measure the dc inputs on the mainboard refering to 0v/gnd with your multimeter set to ohms.
If anything is zero ohms then there is a short.

Udo.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Brotastic on February 25, 2012, 12:09:07 AM
I apologize in advance if this too much of a noob question.  I have looked through the stereo link support thread and many others ....as well as the mnats site, but I can't find the specific parts and the best place to get them for the toggle switches, the led, the stepped pots for meter, and knobs for the 2-1176.  I would very much appreciate any info on these things.  Thank you.

Dan
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: belac on March 11, 2012, 08:40:54 AM
I have ran into a problem I am working on a REV A v1.25 and the instructions say to take pads X and Y on the meter board to the X and Y pads on the Main board... only problem is there is no X and Y on the main board, also there is no G pad
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on March 13, 2012, 12:00:03 PM
I have ran into a problem I am working on a REV A v1.25 and the instructions say to take pads X and Y on the meter board to the X and Y pads on the Main board... only problem is there is no X and Y on the main board, also there is no G pad

Really?  Read it again:
http://mnats.net/1176_reva-d_hairball_wiring_meter_circuit.html

I don't think it says that at all.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: belac on March 13, 2012, 09:03:46 PM
I have ran into a problem I am working on a REV A v1.25 and the instructions say to take pads X and Y on the meter board to the X and Y pads on the Main board... only problem is there is no X and Y on the main board, also there is no G pad

Really?  Read it again:
http://mnats.net/1176_reva-d_hairball_wiring_meter_circuit.html

I don't think it says that at all.

sorry I was referring to http://mnats.net/1176-wiring-rotary.html because I am building a stereo version
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Hairball Audio on March 14, 2012, 02:09:40 AM
Same process.  X and Y connect to the output XLR.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on October 08, 2012, 04:46:56 PM
Just wanted to post an update.  I have been slowly tweaking away on my stereo 1176.  I've been testing and trying a number of different things.  A number of you very helpful member's here have guided me along the way.  Well today was the day I finished all my tweaking and am finally happy with the compressors.  I wanted to say thank you for all your help with it,  it's moving off the bench and into a rack!

One thing I think that made the biggest difference with my build was to remove the stereo link boards and replace it with a 600r output termination switch.  I was able to get my 2 channels close enough that the few times I would use link will be fine without the link boards.  The matching was pretty close!  But the added benefit of being able to switch the 600r in and out was huge (both channels on a stereo switch).  That is one a number of you guys may want to try or heck its DIY just add a few holes and have both link and the 600r's on the outputs.

The other thing was I calibrated my meters to -4 db of reduction not the -10 in the Mnats videos.  I am more concerned about the accuracy with in 5db of reduction.  If I am pulling 10 db its all about slamming it then so its ok if they are off a little.  That also helped with my channel matching to a degree.

Anyway thanks.  Now to finish a few more projects!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mltamisin on March 12, 2013, 09:59:42 AM
I'm noticing 1 of the jumpers on the power supply section of the main board connects CR8 to R85. I have a V2.2 board and R85 isn't on the power section. It's part of the signal preamp section. Is R81 the new jumper location?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on April 07, 2013, 05:39:23 PM
Hi fella's,

anyone have a picture of a dual layout they believe works well? Mnats pictures have his toroid and IEC set in the middle, he suggested putting it to one side, and far away from the output circuit, or potentially using some dividing metal shield. I am building 4 pairs (6 rev D's and 2 rev A's), and using his double PSU board for power, so i can put stuff where ever?
I just want to make double sure i don't weld everything down in a footprint i will regret later

thanx for any help, i will post up a bunch of pics in a bit.
T
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on April 07, 2013, 09:56:21 PM
Here is what i'm thinking, xlrs right behind the output trannys? anything obviously stupid here? I'll pobably cut and drill tommrw on it, any advise would be appreciated. I have not been able to find many pics of this set up.

thanx
T

ps I made the cases out of rack shelves(i have dozens rusting in the back shed), and got the very cool front panels from Dan at collective cases. I would have got the complete cases from him if i didnt have all the shelves laying around, his prices are really fair indeed, the faces are sweet!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on April 07, 2013, 09:56:59 PM
back view
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on May 01, 2013, 03:31:24 PM
T,
   Good luck with your build. I'm a bit further along. I have the ch1 side wired with the exception of the output xlr. Ch2 still needs most of the point to point wiring and of course then calibration for both. Looks like you'll have lots of room with your layout. Should make things easier for you. I'm thinking about adding TRS jacks to the rear panel in parallel with the xlr's so I can use either type of connection down the road.  Regards, Dave

http://imageshack.us/a/img6/1584/211761.jpg
http://imageshack.us/a/img542/5247/211763.jpg
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: 100WChris on May 05, 2013, 10:42:42 AM
Hi!
I´m planning my 2-1176-Layout in a modushop case. Are there some guidelines i should follow? i read somewhere i should put the output-transformer as far away from the power transformator as possible, is that correct? What about the input-iron?
Thanks!
Chris
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on May 06, 2013, 09:54:01 PM
Hi Chris !
  I don't think I have seen anything written that specifically addresses placement of all the various components. Looking at the pictures of various builds on this site, mnats site and even the Universal Audio site does seem to suggest keeping components that are generating a lot of EMF (transformers) as far apart as possible is a good idea :) Good luck with your build.  Regards, Dave
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: 100WChris on May 09, 2013, 03:06:12 PM
Hi Dave!
Thanks! I looked at some pictures and i will try my layout and see what happens. mnats 1RU build is very tight, i guess my layout will work...
Chris
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on May 18, 2013, 01:46:57 PM
EDIT/DISCLAIMER:  *** XLR grounding scheme is not ideal on my drawing*** - will fix this when I have the time.

So I made this diagram for my own future reference but just thought I'd share with you guys - this is exactly how I wired up my stereo Rev. A units, including working stereo link boards.

What I didn't do:
Wire in a true bypass board (I don't need the functionality)
Shield the wires going to pad 15, 16, 17 (I didn't have the cable for it.  Yes, it's bad practice but as long as I kept the wires far away from the power transformer, it didn't bother me.) 
Connect the output pot to the ratio board (in order to place the dual/link switch between the pot and the sidechain)
Use the mnats dual power PSU pcb (to save space)

(http://i969.photobucket.com/albums/ae175/mrerdat/stereo1176wiringdiagram.png) (http://s969.photobucket.com/user/mrerdat/media/stereo1176wiringdiagram.png.html)

Hope this helps some of you guys who are having trouble!

Edit: I didn't have the meter board ground connected in the diagram like I did in my unit.  It's fixed on the diagram now.

Edit 6/16/13: Oh! And one very important thing I forgot to mention to anyone looking at my wiring diagram is that I'm in the middle of a project right now so I haven't had the chance yet to drill mounting holes on the bottom of my case for the transformers/PCBs.  Things are still temporarily secured with gaff tape at the moment (LOL), so this means that my input transformers are not connected to star ground via mounting hardware.  I connect the PCB ground next to pad 22 to the output XLR pin 1 to get that connection for now.  You probably don't want to connect it that way if you are doing it the mnats way from the start, as you will probably get a ground loop.  Just a heads up.

Edit 8/13/13:  It was brought to my attention that the wire connecting the resistor for the VU LEDs (labelled 840 ohms in the diagram) is connected to the wrong power transformer secondary wire.  It should be connected to the black (positive) wire instead of the yellow (negative) one.  I don't have access to the program I made the diagram in at the moment, but will correct this when I get the chance.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on May 20, 2013, 06:55:48 AM
Mrerdat,
   Thanks very much for the diagram !  It's a nice reference and a great help :). Regards, Dave
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Axelerator on May 29, 2013, 12:13:23 PM
..i would like to know if the stereo summing board is out of cuircuit while in mono mode ? staring at the schemo i think so but i am still not very good in understanding where the elektrons go..

greets and thanks,
axel
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: eparg on June 12, 2013, 06:08:21 PM
I'm gathering parts for a stereo 1176 rev a build. Curious as to what lamp people are using for the on indication. I'm using Dan's case, hasn't arrived yet so I don't know what dimension the hole is. Thanks!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on June 13, 2013, 02:33:57 AM
I'm gathering parts for a stereo 1176 rev a build. Curious as to what lamp people are using for the on indication. I'm using Dan's case, hasn't arrived yet so I don't know what dimension the hole is. Thanks!

I have dans front panels, i just bought big blue led's at Fry's electronics, and drilled the holes a little bigger :o ;D
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on June 15, 2013, 02:45:02 PM
I'm gathering parts for a stereo 1176 rev a build. Curious as to what lamp people are using for the on indication. I'm using Dan's case, hasn't arrived yet so I don't know what dimension the hole is. Thanks!

IIRC, the hole Dan drilled for the light on his case is 5/8".  I used a fender amp lamp holder, which has a 11/16" chassis hole so you have to make it slightly bigger... Got these parts from tubesandmore.com:

P-47 (power indicator bulb, 6.3V 0.15A)
P-L110 (front panel indicator lamp)
p-L120 (blue amp jewel)

Now here's the thing.  Stock, the blue lamp jewel looks terrible.  It glows a whitish-purple color, and doesn't even look close to blue.  But I was able to get a Roscolux lighting swatch from one of my jobs and cut a circle out of a color filter sample and stuffed it into the lamp jewel.  You should be able to pick one up for free if there's a local stage/theatre lighting store around.   I was able to match the Dan's blue paint job on the front panel by using a filter color called cerulean blue (#375).  It came out looking great, the lamp looks so much cooler than going the LED route! Here's how it looked when I finished building it a month ago (I didn't have the right resistor at the time so it's a bit brighter than how it looks right now), with all of the boxes of parts in the background for good measure:

(http://i969.photobucket.com/albums/ae175/mrerdat/th_459463_10102581971500299_1151807297_o.jpg) (http://s969.photobucket.com/user/mrerdat/media/459463_10102581971500299_1151807297_o.jpg.html)

I used a 150 ohm resistor wired to the power transformer secondary (see my diagram from a few posts above) and I'm pretty happy with the brightness of the lamp.  I'll upload a much better pic  soon when I get the chance.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mltamisin on June 15, 2013, 02:46:19 PM
regarding the VU meters, do I need 2 separate 280 ohm resistors for wiring each VU meter? I'm noticing the diagram above shows a 840 ohm resistor wired to both. How did you get that value?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on June 15, 2013, 03:31:07 PM
regarding the VU meters, do I need 2 separate 280 ohm resistors for wiring each VU meter? I'm noticing the diagram above shows a 840 ohm resistor wired to both. How did you get that value?

I had a hodgepodge of 220 ohm, 200 ohm, and 100 ohm power resistors around so I wired them in series together in various configurations until I settled on the value that I liked which was 840 ohms.  The (group of) resistor(s) is connected in parallel to both VU meter LEDs to get slightly more of a voltage drop. You don't have to do it this way and you can adjust the brightness to taste... 840 is not a rule, just a preference.  Looks great to me though. 

I don't know as I've never built a single channel 1176, but 280 ohms might be a value for the lamp on the larger hairball VU meter for single channel compressors.  The 8027-WF VU meter LEDs are different and need more resistance.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on June 15, 2013, 03:45:56 PM
BTW if anyone is wondering, the knobs I used for my build were part number 5164-1510AH (http://www.mouser.com/ProductDetail/Davies-Molding/1510AH/?qs=sGAEpiMZZMuiwDVLTMm01ajIGS4kAMb6mWHILx2U4J4%3d) from Mouser which are $1.39 each and look great!  I am not one of those people who spend hundreds of dollars on vintage knobs  :P
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: eparg on June 15, 2013, 07:21:42 PM
I'm gathering parts for a stereo 1176 rev a build. Curious as to what lamp people are using for the on indication. I'm using Dan's case, hasn't arrived yet so I don't know what dimension the hole is. Thanks!

IIRC, the hole Dan drilled for the light on his case is 5/8".  I used a fender amp lamp holder, which has a 11/16" chassis hole so you have to make it slightly bigger... Got these parts from tubesandmore.com:

P-47 (power indicator bulb, 6.3V 0.15A)
P-L110 (front panel indicator lamp)
p-L120 (blue amp jewel)

Now here's the thing.  Stock, the blue lamp jewel looks terrible.  It glows a whitish-purple color, and doesn't even look close to blue.  But I was able to get a Roscolux lighting swatch from one of my jobs and cut a circle out of a color filter sample and stuffed it into the lamp jewel.  You should be able to pick one up for free if there's a local stage/theatre lighting store around.   I was able to match the Dan's blue paint job on the front panel by using a filter color called cerulean blue (#375).  It came out looking great, the lamp looks so much cooler than going the LED route! Here's how it looked when I finished building it a month ago (I didn't have the right resistor at the time so it's a bit brighter than how it looks right now), with all of the boxes of parts in the background for good measure:

(http://i969.photobucket.com/albums/ae175/mrerdat/th_459463_10102581971500299_1151807297_o.jpg) (http://s969.photobucket.com/user/mrerdat/media/459463_10102581971500299_1151807297_o.jpg.html)

I used a 150 ohm resistor wired to the power transformer secondary (see my diagram from a few posts above) and I'm pretty happy with the brightness of the lamp.  I'll upload a much better pic  soon when I get the chance.

Thanks for the great info, I will use that same lamp as it looks great! I happen to work at a theater so I can easily grab some gel for the lamp. Thanks again!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on June 15, 2013, 10:25:16 PM
BTW if anyone is wondering, the knobs I used for my build were part number 5164-1510AH (http://www.mouser.com/ProductDetail/Davies-Molding/1510AH/?qs=sGAEpiMZZMuiwDVLTMm01ajIGS4kAMb6mWHILx2U4J4%3d) from Mouser which are $1.39 each and look great!  I am not one of those people who spend hundreds of dollars on vintage knobs  :P

You are right on sir, those look cool, thanks for the tip ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on June 16, 2013, 09:54:35 AM
Thanks for the great info, I will use that same lamp as it looks great! I happen to work at a theater so I can easily grab some gel for the lamp. Thanks again!

You are right on sir, those look cool, thanks for the tip ;)

No problem guys, glad I could help! 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: eparg on June 16, 2013, 07:08:04 PM
I would love to have the functionality of a true bypass, but seeing as Igor's store is closed does anyone else offer a true bypass pcb? Or is it something that wouldn't be too hard to make p2p?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on June 16, 2013, 08:01:26 PM
There was another member doing true bypass boards with a built in psu.  That is what I put in mine.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on June 16, 2013, 10:49:36 PM
There was another member doing true bypass boards with a built in psu.  That is what I put in mine.

This is the one Dan is talking about.

http://www.groupdiy.com/index.php?topic=44049.0
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on June 16, 2013, 11:23:05 PM
Yep!  That is the one.  I think I powered it differently then using the on board PSU.  I can't remember I would have to take my comps out of the rack and look. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: eparg on June 18, 2013, 01:07:43 AM
Thanks for pointing me in the right direction for the relay! Will begin building later this week  :D
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mltamisin on June 18, 2013, 06:07:07 PM
OK, so the PSU connection.... if you're facing the main PCB board so you can read the legending (AC, CT, AC), is the right negative and the left positive? Don't want to fry anything.

Figure it out: It's the opposite of what I thought. Lucky I didn't fry anything.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dribro on June 18, 2013, 10:45:07 PM
hi guy's

How about this one? and it is suitable for various projects. You only have to fit parts accordinly to your supply. I'm gathering parts for my gssl's and the dual 1176.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mltamisin on June 19, 2013, 09:43:19 AM
Wow, these meters are super bright! I see why the 840 ohm resistor was used. Gonna add some resistance to these.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on June 21, 2013, 11:00:21 AM
Hi,

here is my Dual 1176 in a a Purusha case (very small !)
Take a look : http://flic.kr/s/aHsjGfrsE3 (http://flic.kr/s/aHsjGfrsE3)

Everything looks good... same compression response on channel A & B, sounds good etc.
Today I can hear (sometimes...) a noise "hummm" begin at maybe 90 or 100 Hz with some octaves.... The noise comes and disappear.... sometimes he's here 5 secondes, sometimes he's here 3 minutes and gone....
I dont know what's this s##t !
Here is an exemple : http://youtu.be/Isni2B59dE4 (http://youtu.be/Isni2B59dE4)

Someone has an idea ??
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mltamisin on June 24, 2013, 02:33:50 PM
I reworked the wiring and noticed my +30v rail was slightly high. As I was adjusting R7 (variable trim 5k) I may have fried something. Saw some smoke and R4 & R6 looked fat a bulged out so I replaced them and also installed fixed value resistors in R3 (2.7K ohm) and R5 (840 ohm) instead of the 5k trimmers in case they went out too. Now my rail is reading +35v! 5k trimmers measure out fine. Something else has to be burnt out. Maybe a diode? Would that be visible?
I reordered new 5k trimmers. Can I make a breadboard circuit with 30v and -10 test points to trim out this guy before I connect it to the main PCB? I really don't want to trim out the voltage while it's in circuit.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 07, 2013, 02:43:01 AM
When using the external PSU I noticed http://mnats.net/psu.html is using the G1176 board and the Jumpers do not match the parts on M.NATS 1176 rev D 2.2 PCB

I noticed germoju has CR7 going to <+30V (R87) and CR10 going to -10V (CR6)

Is this correct?

I have not been able to find any explicit answer to this.... but I have noticed the question come up, unanswered.

Thanks :)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: hymentoptera on July 07, 2013, 05:00:06 AM
Hi,

here is my Dual 1176 in a a Purusha case (very small !)
Take a look : http://flic.kr/s/aHsjGfrsE3 (http://flic.kr/s/aHsjGfrsE3)

...

not sure what's causing the humm, maybe something external, like computer monitor, or...

I just wanted to say that your dualie looks good. I like how the boards are stacked, I was wondering myself if that was possible in a 2RU enclosure. Hope you get the hum issue sorted out soon!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: eparg on July 07, 2013, 12:19:11 PM
When using the external PSU I noticed http://mnats.net/psu.html is using the G1176 board and the Jumpers do not match the parts on M.NATS 1176 rev D 2.2 PCB

I noticed germoju has CR7 going to <+30V (R87) and CR10 going to -10V (CR6)

Is this correct?

I have not been able to find any explicit answer to this.... but I have noticed the question come up, unanswered.

Thanks :)

I believe you can wire directly to the test points (+30,-10,gnd) without having to jump anything. I could be wrong. Best to check the schematic to be sure. Also verify (beep) with a multimeter.

Hope that helps.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 09, 2013, 06:12:45 AM
Hi,

here is my Dual 1176 in a a Purusha case (very small !)
Take a look : http://flic.kr/s/aHsjGfrsE3 (http://flic.kr/s/aHsjGfrsE3)

...

not sure what's causing the humm, maybe something external, like computer monitor, or...

I just wanted to say that your dualie looks good. I like how the boards are stacked, I was wondering myself if that was possible in a 2RU enclosure. Hope you get the hum issue sorted out soon!

Thanks... Case is 225 mm large... That´s really small and i had to test a lot of PCB position to reduce the "hummmmm"
that's maybe something external... I hope so... I passed so many times on that machine !!!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 09, 2013, 06:15:36 AM
When using the external PSU I noticed http://mnats.net/psu.html is using the G1176 board and the Jumpers do not match the parts on M.NATS 1176 rev D 2.2 PCB

I noticed germoju has CR7 going to <+30V (R87) and CR10 going to -10V (CR6)

Is this correct?

I have not been able to find any explicit answer to this.... but I have noticed the question come up, unanswered.

Thanks :)

I believe you can wire directly to the test points (+30,-10,gnd) without having to jump anything. I could be wrong. Best to check the schematic to be sure. Also verify (beep) with a multimeter.

Hope that helps.

Yes yes ....
you can plug directly to +30 and -10 without jumper cause you come from the PSU Board witch gives you the +30V / - 10V.... And that a better solution to avoid jumper...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 09, 2013, 09:08:42 AM
Did you remove the paint behind the switches and pots so they make solid contact to ground?  You don't want them to float. 

Many people have built stereo 1176's into my cases with no noise.  The project is great in a 2u.  My guess is something ground related. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 09, 2013, 09:26:01 AM
Did you remove the paint behind the switches and pots so they make solid contact to ground?  You don't want them to float. 

Many people have built stereo 1176's into my cases with no noise.  The project is great in a 2u.  My guess is something ground related.

Yes I did remove paint between switches and pots...
Thanks ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 10, 2013, 04:03:12 PM
When using the external PSU I noticed http://mnats.net/psu.html is using the G1176 board and the Jumpers do not match the parts on M.NATS 1176 rev D 2.2 PCB

I noticed germoju has CR7 going to <+30V (R87) and CR10 going to -10V (CR6)

Is this correct?

I have not been able to find any explicit answer to this.... but I have noticed the question come up, unanswered.

Thanks :)

I believe you can wire directly to the test points (+30,-10,gnd) without having to jump anything. I could be wrong. Best to check the schematic to be sure. Also verify (beep) with a multimeter.

Hope that helps.

Yes yes ....
you can plug directly to +30 and -10 without jumper cause you come from the PSU Board witch gives you the +30V / - 10V.... And that a better solution to avoid jumper...

Thanks so much for the reply - noted!

I also noticed CR7 & CR10 lead to the AC terminals - hence the reason for jumping from CR7 to <+30V (R87) & CR10 to -10V (CR6) - this is best, in case you are set on using the terminal blocks.

Excuse my n00bish questions (I am a n00b)...... with regards to the LED ratings on MNATS Little PSU ... what are the minimum Voltage and Current ratings required.... I dont want them to burn out! :)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 10, 2013, 06:38:07 PM
hey !

for the LEDs I used 3mm with resistors values 390R for R1 and 1k5 for R2  ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 10, 2013, 06:44:38 PM
Yes I did remove paint between switches and pots...
Thanks ;)

I had lowend noise before I did this and it fixed it for me.  I would say try using a alligator clip and connecting it to star ground and then try testing the pots and switches again and see if the noise drops or changes at all.  Just to be sure to rule it out.  Other wise does it make a difference if the top is on or off of the case?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 11, 2013, 07:18:44 AM
I got a good continuity test between pots, switches and ground...
I will try what you told me...

my ON/OFF switch : http://www.banzaimusic.com/DPDT-on-on-Toggle-15A-250V.html (http://www.banzaimusic.com/DPDT-on-on-Toggle-15A-250V.html)

Other wise does it make a difference if the top is on or off of the case?
I have to test it again cause actually the machine is racked... I will unrack soon to verify...

Today I tested continuity with knobs 's screws. I got 0,4 ohm maximum...
only ratio knobs are 1,9 and the other 1,4 ohm. I will fix this soon...
I can see the noise louder on channel B than the channel A...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 11, 2013, 09:19:42 AM
I just looked at your photos again.  It looks like your wiring to your power switch isn't shielded.  That could be the problem specially if the second channel is noisier then the first.  Try removing it from the front panel and pulling the wires away from the other wiring.  Then carefully check for noise again.  You may need to shield that wiring and so it dumps noise to the star ground and not into your audio.  I do that for all my builds now.

If you do, then I recommend covering the shield with something like shrink wrap.  Then if the power wires break they don't make contact to the shield, and then to the chassis, and then you. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 11, 2013, 09:26:47 AM
I just looked at your photos again.  It looks like your wiring to your power switch isn't shielded.  That could be the problem specially if the second channel is noisier then the first.  Try removing it from the front panel and pulling the wires away from the other wiring.  Then carefully check for noise again.  You may need to shield that wiring and so it dumps noise to the star ground and not into your audio.  I do that for all my builds now.

If you do, then I recommend covering the shield with something like shrink wrap.  Then if the power wires break they don't make contact to the shield, and then to the chassis, and then you.

oh ok ! But how to shield a wire ?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on July 11, 2013, 09:46:40 AM
I found a bunch of metal braid wire at a local store that I fit over the PSU wires.  (maybe someone here has a part #)  Then I soldered a ground wire to the shield and connected that end to the star ground.  Then slip plastic cover over it to protect yourself from any damage wires in the future.  It takes a little work but its safe and helps with noise. 

I have done this on my LA 3A's, La 2A's and my 1176's.  Anytime I have mains PSU switches running to the front panels. Specially if its in the center between channels. There is never a clean path away from other controls on the second channel and this does help.

Also, it looks like your front panel is bare aluminum so, as long as your front panel has good continuity to the star ground then your pots and switches should be grounded as well. 

Good luck.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 11, 2013, 09:58:24 AM
Ok thanks ! I will try :)
I find copper scotch on internet... Specialy to reduce magnetic fields...
I'll tell you when it´s done ;)


Édit : http://www.conrad.fr/ce/fr/overview/2301041/Adhsif-de-blindage (http://www.conrad.fr/ce/fr/overview/2301041/Adhsif-de-blindage)

Or better ??? => http://www.conrad.fr/ce/fr/product/545613/Gaine-texture-tisse-mtallique-SCOTCH-24-L-x-l-45-m-x-25-mm-3M-80-0120-2401-6 (http://www.conrad.fr/ce/fr/product/545613/Gaine-texture-tisse-mtallique-SCOTCH-24-L-x-l-45-m-x-25-mm-3M-80-0120-2401-6)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 11, 2013, 12:29:08 PM
hey !

for the LEDs I used 3mm with resistors values 390R for R1 and 1k5 for R2  ;)

Is there a minimum current and voltage rating for the LEDs eg. 5v 40mA? ... Or should any 3mm LED be fine
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on July 11, 2013, 01:30:03 PM
hey !

for the LEDs I used 3mm with resistors values 390R for R1 and 1k5 for R2  ;)

Is there a minimum current and voltage rating for the LEDs eg. 5v 40mA? ... Or should any 3mm LED be fine

If your leds are 5v 40mA and you have +30v and -10v
30 - 5 = 25
25 \ 0,04 = 625 ohm -> use 650 ohm

10 - 5 = 5
5 / 0,04 = 125 ohm -> use 150 ohm

Let the others confirm that cause i'm really not sure !!!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 14, 2013, 04:02:38 AM
hey !

for the LEDs I used 3mm with resistors values 390R for R1 and 1k5 for R2  ;)

Is there a minimum current and voltage rating for the LEDs eg. 5v 40mA? ... Or should any 3mm LED be fine

If your leds are 5v 40mA and you have +30v and -10v
30 - 5 = 25
25 \ 0,04 = 625 ohm -> use 650 ohm

10 - 5 = 5
5 / 0,04 = 125 ohm -> use 150 ohm

Let the others confirm that cause i'm really not sure !!!

Thanks for your reply, I would be more comfortable going with a definitive answer - but thanks none the less! :)

Basically, I just want to know what the minimum ratings (voltage & Current) need to be for the 3mm LEDs on MNATS little PSU when using the 390ohm (R1) and 1500ohm (R2) on MNATs BOM
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Harpo on July 14, 2013, 08:22:31 AM
Basically, I just want to know what the minimum ratings (voltage & Current) need to be for the 3mm LEDs on MNATS little PSU when using the 390ohm (R1) and 1500ohm (R2) on MNATs BOM
Look up the parts datasheet for the LED you are going to order.
Depending on colour (not diameter) of this LED, this will have a forward voltage VF in range 1.6V ... 3.6V and a forward current IF of maybe 20mA ... 30mA for your type of LED. This IF is the rating you don't want to exceed (the opposit of your 'minimum current' request) and some datasheets give a recommended IF 'Rec if' of about half this max.IF value.
The current limiting resistor needed to not exceed LED parts limits and to not build a headlight is (Supply voltage in V - LEDs forward voltage in V) / allowed forward current in A.
A red LED might come with a typical 2V VF and 20mA IF. Allow for maybe half this IF. For your 30VDC status display this resistor would be (30V - 2V)/0.01A=2800 ohm. A 2K7 standard parts value would allow for (30V-2V)/2700R=10.4mA. This resistor has to dissipate (30V-2V)*0.0104A=0.29W. Double up this rating, a 0.6W rated resistor will fit the bill.
The R1 and R2 values from MNats BOM might refer to different psu output voltages. The schematic already tells you "select for propper LED current given selected output voltage".
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 16, 2013, 03:37:36 PM
Basically, I just want to know what the minimum ratings (voltage & Current) need to be for the 3mm LEDs on MNATS little PSU when using the 390ohm (R1) and 1500ohm (R2) on MNATs BOM
Look up the parts datasheet for the LED you are going to order.
Depending on colour (not diameter) of this LED, this will have a forward voltage VF in range 1.6V ... 3.6V and a forward current IF of maybe 20mA ... 30mA for your type of LED. This IF is the rating you don't want to exceed (the opposit of your 'minimum current' request) and some datasheets give a recommended IF 'Rec if' of about half this max.IF value.
The current limiting resistor needed to not exceed LED parts limits and to not build a headlight is (Supply voltage in V - LEDs forward voltage in V) / allowed forward current in A.
A red LED might come with a typical 2V VF and 20mA IF. Allow for maybe half this IF. For your 30VDC status display this resistor would be (30V - 2V)/0.01A=2800 ohm. A 2K7 standard parts value would allow for (30V-2V)/2700R=10.4mA. This resistor has to dissipate (30V-2V)*0.0104A=0.29W. Double up this rating, a 0.6W rated resistor will fit the bill.
The R1 and R2 values from MNats BOM might refer to different psu output voltages. The schematic already tells you "select for propper LED current given selected output voltage".

Thanks, that actually makes sense now, took me some time but I think I got it now.

If im not mistaken

"red LED might come with a typical 2V VF and 20mA IF for 30VDC status display"

Would be (30V - 2V)/0.02A=1400 ohm ??
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Harpo on July 16, 2013, 04:21:39 PM
Basically, I just want to know what the minimum ratings (voltage & Current) need to be for the 3mm LEDs on MNATS little PSU when using the 390ohm (R1) and 1500ohm (R2) on MNATs BOM
Look up the parts datasheet for the LED you are going to order.
Depending on colour (not diameter) of this LED, this will have a forward voltage VF in range 1.6V ... 3.6V and a forward current IF of maybe 20mA ... 30mA for your type of LED. This IF is the rating you don't want to exceed (the opposit of your 'minimum current' request) and some datasheets give a recommended IF 'Rec if' of about half this max.IF value.
The current limiting resistor needed to not exceed LED parts limits and to not build a headlight is (Supply voltage in V - LEDs forward voltage in V) / allowed forward current in A.
A red LED might come with a typical 2V VF and 20mA IF. Allow for maybe half this IF. For your 30VDC status display this resistor would be (30V - 2V)/0.01A=2800 ohm. A 2K7 standard parts value would allow for (30V-2V)/2700R=10.4mA. This resistor has to dissipate (30V-2V)*0.0104A=0.29W. Double up this rating, a 0.6W rated resistor will fit the bill.
The R1 and R2 values from MNats BOM might refer to different psu output voltages. The schematic already tells you "select for propper LED current given selected output voltage".

Thanks, that actually makes sense now, took me some time but I think I got it now.

If im not mistaken

"red LED might come with a typical 2V VF and 20mA IF for 30VDC status display"

Would be (30V - 2V)/0.02A=1400 ohm ??
Theoretically yes for the LEDs max.allowed current. Exceeding this abs.max.parts rating might blow this part. From your quote you left out my "Allow for maybe half this IF".
As initially said, "Look up the parts datasheet for the LED you are going to order".
All parts come with more or less tolerances. The selected type of LED (they are not all the same, varying in wavelength, brightness, viewing angle, ...) might have a typical 2.0V forward voltage, that could vary by +/-some hundred mV. Resistors come with tolerances. Your psu has a trimmer for dialing in the target voltage and initially you might have dialed in too much when powering on the 1st.time. From Murphys law all tolerances will add in a direction where it will cause the greatest harm.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 17, 2013, 02:48:23 PM
Basically, I just want to know what the minimum ratings (voltage & Current) need to be for the 3mm LEDs on MNATS little PSU when using the 390ohm (R1) and 1500ohm (R2) on MNATs BOM
Look up the parts datasheet for the LED you are going to order.
Depending on colour (not diameter) of this LED, this will have a forward voltage VF in range 1.6V ... 3.6V and a forward current IF of maybe 20mA ... 30mA for your type of LED. This IF is the rating you don't want to exceed (the opposit of your 'minimum current' request) and some datasheets give a recommended IF 'Rec if' of about half this max.IF value.
The current limiting resistor needed to not exceed LED parts limits and to not build a headlight is (Supply voltage in V - LEDs forward voltage in V) / allowed forward current in A.
A red LED might come with a typical 2V VF and 20mA IF. Allow for maybe half this IF. For your 30VDC status display this resistor would be (30V - 2V)/0.01A=2800 ohm. A 2K7 standard parts value would allow for (30V-2V)/2700R=10.4mA. This resistor has to dissipate (30V-2V)*0.0104A=0.29W. Double up this rating, a 0.6W rated resistor will fit the bill.
The R1 and R2 values from MNats BOM might refer to different psu output voltages. The schematic already tells you "select for propper LED current given selected output voltage".

Thanks, that actually makes sense now, took me some time but I think I got it now.

If im not mistaken

"red LED might come with a typical 2V VF and 20mA IF for 30VDC status display"

Would be (30V - 2V)/0.02A=1400 ohm ??
Theoretically yes for the LEDs max.allowed current. Exceeding this abs.max.parts rating might blow this part. From your quote you left out my "Allow for maybe half this IF".
As initially said, "Look up the parts datasheet for the LED you are going to order".
All parts come with more or less tolerances. The selected type of LED (they are not all the same, varying in wavelength, brightness, viewing angle, ...) might have a typical 2.0V forward voltage, that could vary by +/-some hundred mV. Resistors come with tolerances. Your psu has a trimmer for dialing in the target voltage and initially you might have dialed in too much when powering on the 1st.time. From Murphys law all tolerances will add in a direction where it will cause the greatest harm.

Ahhhh that makes perfect sense! thanks for being so patient with me and taking the time to explain, got it now!! :D Thanks Harpo and everyone, Im sure this will also serve other n00bs like me in future :)

So going on all of this :

I have a RED LED : Vf = 5v, If = (max. 17.5mA) (typ. 13mA)
Green LED :  Vf = 5v, If = (max. 17.5mA) (typ. 11.5mA)

(30-5)/0.013 = 1923 (1.96 kOhms 0.5W 1%)
(10-5)/0.0115 =435 (432 Ohms 0.5w 1%)

Correct?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Harpo on July 18, 2013, 05:23:42 AM
I have a RED LED : Vf = 5v, If = (max. 17.5mA) (typ. 13mA)
Green LED :  Vf = 5v, If = (max. 17.5mA) (typ. 11.5mA)

(30-5)/0.013 = 1923 (1.96 kOhms 0.5W 1%)
(10-5)/0.0115 =435 (432 Ohms 0.5w 1%)

Correct?
I doubt you have selected a standard LED (from your previous posts a standard LED, through hole, diameter 3mm, colour red, avail.in singles). The typical forward voltage of red GaP or GaAsP LEDs is in range 2.0 ...2.5V. Your given voltage and current values seem to reference a LED module with already built in resistor to operate at these ratings. Could you post a link to this part?
A 3mm through hole standard LED in bulk might be something like  these (http://uk.mouser.com/ProductDetail/Lite-On/LTL42NKRKNN/?qs=sGAEpiMZZMvHYEB9WUp7Ehno5%252b49mJeJoriHlOVWjNg%3d) or these (http://www.reichelt.de/LEDs-standard-hell/LED-3MM-ST-RT/3/index.html?;ACTION=3;LA=2;ARTICLE=6828;GROUPID=3018;artnr=LED+3MM+ST+RT).
Ps: updating your profile with your location data might make it easier to help you.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on July 20, 2013, 04:33:42 AM
I have a RED LED : Vf = 5v, If = (max. 17.5mA) (typ. 13mA)
Green LED :  Vf = 5v, If = (max. 17.5mA) (typ. 11.5mA)

(30-5)/0.013 = 1923 (1.96 kOhms 0.5W 1%)
(10-5)/0.0115 =435 (432 Ohms 0.5w 1%)

Correct?
I doubt you have selected a standard LED (from your previous posts a standard LED, through hole, diameter 3mm, colour red, avail.in singles). The typical forward voltage of red GaP or GaAsP LEDs is in range 2.0 ...2.5V. Your given voltage and current values seem to reference a LED module with already built in resistor to operate at these ratings. Could you post a link to this part?
A 3mm through hole standard LED in bulk might be something like  these (http://uk.mouser.com/ProductDetail/Lite-On/LTL42NKRKNN/?qs=sGAEpiMZZMvHYEB9WUp7Ehno5%252b49mJeJoriHlOVWjNg%3d) or these (http://www.reichelt.de/LEDs-standard-hell/LED-3MM-ST-RT/3/index.html?;ACTION=3;LA=2;ARTICLE=6828;GROUPID=3018;artnr=LED+3MM+ST+RT).
Ps: updating your profile with your location data might make it easier to help you.



Oh okay, yeah when I filtered Lens Color/Style (Green / Red) it was only returning 1 result for  This (http://uk.mouser.com/ProductDetail/Kingbright/WP710A10ID5V/?qs=sGAEpiMZZMvHYEB9WUp7EiQZxlvRfFmoyhbLHNWbBDg%3d) I see illumination colour is what I wanted to be looking at.

Ive got this (http://uk.mouser.com/ProductDetail/Everlight/264-7SYGD-S530-E2/?qs=sGAEpiMZZMvHYEB9WUp7EuGLmjv33pVVQ037aZrH2mQ%3d) and this (http://uk.mouser.com/ProductDetail/Dialight/521-9216F/?qs=sGAEpiMZZMvHYEB9WUp7EvzO6BrrarQcHhA%2fV%252b9D8YI%3d) in my cart now

So going on what was said previously

(30-2)/0.01 = 2800 (2k7  0.5W 2%)
(10-2)/0.01 =800 (820 0.5W 2%)

Correct now?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Harpo on July 20, 2013, 08:07:02 AM
Yepp.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on August 08, 2013, 05:31:34 AM
HI !
just wanna say : My Dual 1176 is WORKING without Hummmm or bzzzzzzz !!! YEAH !!

The buzzzz was causing by my front panel red LED !!! I unplug it from DC Current and take my Voltage on AC and buzzz 's gone ! Youuuhou !

Thanks a lot everybody who helped me !!!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on August 20, 2013, 02:30:49 PM
I'm close to completing my stereo 1176 build (rotary) and I notice I have not connected anything to the ground pad on the MNATS meter board. In the pictures from the MNATS site it looks like something is soldered to that pad but I cant tell what. I have re-read it several times and unless I'm missing it I dont see where it's mentioned. Perhaps it's just common sense that pad would be tied to one of the ground pads on the main circuit board ?  Thanks, Dave
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on August 21, 2013, 02:53:49 AM
I'm close to completing my stereo 1176 build (rotary) and I notice I have not connected anything to the ground pad on the MNATS meter board. In the pictures from the MNATS site it looks like something is soldered to that pad but I cant tell what. I have re-read it several times and unless I'm missing it I dont see where it's mentioned. Perhaps it's just common sense that pad would be tied to one of the ground pads on the main circuit board ?  Thanks, Dave

Hi,

It's for bypass...
I connected Mnats Meter Board 22/GND > to bypass switch > to Mnats Main board 22/GND
So when my switch is on "Bypass" it connects 22 to GND...

hope I helped ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on August 22, 2013, 08:10:28 AM
Hi everybody !
I'm building a second Dual 1176 with Revision A this time...
I buyed new Purusha case witch is 275 mm now ! So more space !!! :)

Here is a picture... What do you think about transfos positions ?? Toroid in the middle etc...

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on August 30, 2013, 10:57:56 AM
germoju,
  Looks good ! Thats just about how I placed everything for my rev D.  :) By the way I finished my build last night and began calibration. Got through the first two steps and everything is looking good so far. I hope to finish up tonight :) Regards, Dave   
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on September 03, 2013, 10:06:43 AM
Hi Everyone !
   Finished up my dual 1176 rev D !  Completed calibration last night. Unit sounds great and is dead quiet. Many thanks to Mike at Hairball, Dan at Collective Cases and Mnats. Have a look at some pics !! Regards, Dave

http://imageshack.us/a/img31/6182/oj9.JPG
http://imageshack.us/a/img689/3986/0ouj.jpg
http://imageshack.us/a/img543/8149/ezcs.jpg
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: germoju on September 03, 2013, 03:26:14 PM
Hi Everyone !
   Finished up my dual 1176 rev D !  Completed calibration last night. Unit sounds great and is dead quiet. Many thanks to Mike at Hairball, Dan at Collective Cases and Mnats. Have a look at some pics !! Regards, Dave

http://imageshack.us/a/img31/6182/oj9.JPG
http://imageshack.us/a/img689/3986/0ouj.jpg
http://imageshack.us/a/img543/8149/ezcs.jpg

Cool :) Good pictures !!
It's a Dual Mono... I cant see any stereo link boards.... (??!!)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on September 03, 2013, 04:52:27 PM
germoju,
   No I didn't add the stereo link boards. I have the boards and components but I don't see myself using it in stereo mode much. I'll probably add them down the road when I'm feeling the need to DIY :) Right now just enjoy it as is. Same for the bypass capabilities. :) I have a Drawmer 68ME that I use as a stereo buss compressor so I really intend to use the 1176 for recording and mixing individual tracks. Thanks for the compliment on the pics. I'm very happy how everything turned out :)  Regards, Dave
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: 100WChris on September 11, 2013, 02:13:33 PM
Hi!
Finally finished my Stereo-1176  ;D
(http://www.chrisreiss.de/DIY/2-1176.jpg)
looks wild, but the unit is totally quiet
(http://www.chrisreiss.de/DIY/2-1176_innen.jpg)
transformer and link-boards are under the main-pcbs
(http://www.chrisreiss.de/DIY/2-1176_innen2.jpg)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on September 11, 2013, 02:57:59 PM
Nice!  I love how much space you gain by tucking the transformers and stereo link boards under the main PCBs.  I didn't even notice the little mounting bracket for the output transformer at first glance.  Very cool. 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mnats on September 11, 2013, 07:20:41 PM
Hi!
Finally finished my Stereo-1176  ;D

Looks great!

Why not post it to the official Hairball Audio: 1176 Stereo Linking PCBs Support Thread (http://www.groupdiy.com/index.php?topic=35656.0) as well, since it looks like you used Hairball's boards?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: 100WChris on September 12, 2013, 06:14:24 AM
done
EDIT: mrerdats layout from post 66 helps a lot!!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: DaveHilltop on September 12, 2013, 10:47:45 AM
100WChris,
   Sweet looking build !! Congrats :)   Regards, Dave
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mnats on September 12, 2013, 11:31:17 PM
done

Great, thanks!

EDIT: mrerdats layout from post 66 helps a lot!!

Unfortunately the grounding scheme for the XLRs on that drawing isn't ideal. But we'll save the best advice for the official thread (http://www.groupdiy.com/index.php?topic=35656.0) ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: EvLoutonian on September 13, 2013, 10:39:43 PM
Hi guys.
I have a pair of old UTC H-8 input / matching transformers.
I 'm wondering if they would be suitable for my stereo 1176 input transformers.
They are military spec transformers, and freq response is indicated as flat from 50-10k Hz, but the spec sheet also suggests that they are good for beyond that range.
(https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-ash3/p206x206/1239421_10153216966290282_1118378768_n.jpg)

Cheers,
Evan.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: mrerdat on September 18, 2013, 12:19:14 PM
Unfortunately the grounding scheme for the XLRs on that drawing isn't ideal. But we'll save the best advice for the official thread (http://www.groupdiy.com/index.php?topic=35656.0) ;)

I agree with you there... it was a pretty hacky workaround for when I had floating PCBs in my case secured with gaff tape since I didn't have the tools/time to properly drill and mount things to the chassis before a big project that I had a few months ago.  I'll edit that post with a warning so I don't mislead people with bad grounding.

Probably the most helpful thing from my drawing is how the stereo link boards are connected.  I found the info a bit scattered and confusing while working on my build so it's nice to see that in one place.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: 100WChris on September 18, 2013, 12:43:55 PM
Quote
Probably the most helpful thing from my drawing is how the stereo link boards are connected.  I found the info a bit scattered and confusing while working on my build so it's nice to see that in one place.

That´s exactly what i used it for  :)
Thanks for your effort!
Chris
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 06, 2013, 07:15:40 PM
Hi everybody!

Some miscellaneous questions about my 1176 build, basically parts:
1. switch, should i use:[/li type=decimal]Meter
2. power led and holder...  any recommendations?
3. knobs: I would really like to find something similar to the 2-1176 from UA, I kind of like those roundy knobs. Alternativelly I wouldn't mind to get some metallic/aluminium ones, of white or gray color and cylindrical. Any recommendations?   


Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Unit7 on December 07, 2013, 01:08:57 AM
Hi everybody!

Some miscellaneous questions about my 1176 build, basically parts:
1. switch, should i use:[/li type=decimal]Meter
  • http://www.mouser.com/ProductDetail/Lorlin/CK1592/?qs=sGAEpiMZZMtdU8v%2fCHkq3yHDk2fm8aQh
  • http://www.mouser.com/ProductDetail/ALPS/SRRM433700/?qs=4QwOlnKYOEsVs7%252b5af2rdg%3d%3d
  • if I want to have the +8 as well? http://www.mouser.com/ProductDetail/ALPS/SRRM342800/?qs=4QwOlnKYOEtMus9aF%252bYBQQ%3d%3d
2. power led and holder...  any recommendations?
3. knobs: I would really like to find something similar to the 2-1176 from UA, I kind of like those roundy knobs. Alternativelly I wouldn't mind to get some metallic/aluminium ones, of white or gray color and cylindrical. Any recommendations?

I'm planning to do a stereo unit too. Doing some research from time to time, and regarding the knobs I found these at eBay (only 1/4 shaft though):
http://www.ebay.com/itm/TWO-new-copy-3-4-RCA-type-knobs-black-w-white-line-standard-1-4-shaft-KA-/321203133973?pt=US_Vintage_Pro_Audio_Equipment&hash=item4ac932de15
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on December 07, 2013, 01:39:56 AM
Hairball audio may have the knobs.  Check with Mike.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 07, 2013, 12:38:32 PM
I'm planning to do a stereo unit too. Doing some research from time to time, and regarding the knobs I found these at eBay (only 1/4 shaft though):
http://www.ebay.com/itm/TWO-new-copy-3-4-RCA-type-knobs-black-w-white-line-standard-1-4-shaft-KA-/321203133973?pt=US_Vintage_Pro_Audio_Equipment&hash=item4ac932de15

Wow, $24 for TWO? That is crazy, are they made of emeralds?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on December 07, 2013, 01:16:36 PM
I have a similar question to the ones asked previously...

Are these the correct Rotary Switches for the Meter and Ratio Board - I found them in a Rev D BOM

(4 Pole - 3 Positions)
http://uk.mouser.com/ProductDetail/Lorlin/CK1057/?qs=%2fha2pyFaduj4gRj15JfhdorbufEvFJfJXuu%252bEv8koNc%3d

(2 Pole - 6 Positions)
http://uk.mouser.com/ProductDetail/Lorlin/CK1055/?qs=%2fha2pyFaduhJ%252bdXyu7eNQ9qHO86SsLfFT1B9cn15eVo%3d

Which is ambigious to this found on Mnats Page

2 Pole - 5 Positions)
http://uk.mouser.com/ProductDetail/Alpha-Taiwan/SR2921F-0205-19R0B-E9-S-W/?qs=sGAEpiMZZMvNbjZ2WlReYnqYHrQfuERs6ym%252bj4ABW1I%3d

I noticed DIYRacked Case to have 2 labeled Positions for the meter switch and 6 for the Ratio and Collective cases has 3 positions for the Meter Switch and 5 positions for the Ratio? O_o

Also, is there a measurement for the gaping Power Switch hole on either case?

A Bit Confusing with no definitive answers floating around - Please help!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 08, 2013, 12:09:28 AM
On the collectivecases one the GR bypass is in the meter, so you need 3 positions in the meter switch and 5 positions (4,8,12,20,ALL) in the ratio one.

On the other case the GR bypass is actually in the ratio board (marked as position 1) so you are going to need a 3 pole 6 positions for the ratio and a 2 pole 2 positions for the meter
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 08, 2013, 12:22:50 AM
Also... those references from lorlin... isn't the shaft way too long? 38mm feels a bit too much.

What is the recommended shaft length for the collectivecases case?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on December 08, 2013, 01:15:28 AM
On the collectivecases one the GR bypass is in the meter, so you need 3 positions in the meter switch and 5 positions (4,8,12,20,ALL) in the ratio one.

On the other case the GR bypass is actually in the ratio board (marked as position 1) so you are going to need a 3 pole 6 positions for the ratio and a 2 pole 2 positions for the meter

Okay I understand the visual differences on the Face Plate of the Two and how they would require different position amounts and where the change in positions between the two is due to bypass being on the ratio or meter switch - but is that not determined by the PCB / wiring rather? you say 3 Pole 6 positions but the board only fits 2 pole and 4 pole? - Is there a different way of wiring for different position amounts?

(4-pole - 2 pos (Meter) / 2pole- 6 pos. (Ratio) - [DIY Racked labeling])

(4 pol - 3 pos. (Meter) / 2pole - 5 pos (Ratio) - [Collective Cases labeling])

The latest and previous BOM on mnats page only calls for a 2 and 4 Pole Lorlin rotary switch - no positions mentioned

The original rev D BOM calls for a 4 Pole 3 Position / 2 Pole 6 Position - defined but ambiguous to the case labels.

This makes it really hard to know which Switches to Choose - Could someone please provide an explanation?

With Regards to Lorlin shaft lengths, they are long and plastic and need to be trimmed to your required length.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 08, 2013, 02:36:43 AM
Sorry, I meant two pole / 6 positions

I honestly dont know how to wire the 1:1 ratio in the diy racked case...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 09, 2013, 03:03:14 PM
I am doing some modifications to my stereo 1176...

1. I am adding the super-slow attack mode by using the SPDT switch in the attack pot to either have a 0.022uF (max 0.8ms time) or a 0.22uF (~8ms attack time)
2. I am cannibalizing some of the MC77 design to build a small side board that does the following:
   a) In/Out real bypass (with buffered meter option)
   b) relay switched 150Hz HPF sidechain
   c) relay switched send/return sidechain
   d) relay switched stereo link (because i cannot fit in my case DPDT switches with the DPDT power switch).
   e) Dedicated 24V power supply for switches and lamp.

The board is going to use SMD resistors to save space, I will try to get the schematics sanitized first here, but after that I can share the pcb files if somebody is interested.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 11, 2013, 03:20:25 PM
I have a question concerning my board....

While I understand that switching in a .22uF capacitor instead of C27 will increase the attack time to 8ms, I wonder what would be the effect on the release times... Will it be increased as well? Has anybody done an approximate analysis of the time constants in the circuit? Because I would like to increase the attack time without affecting the release too much.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 12, 2013, 09:03:31 PM
well, this is the horrible board I have managed to design. I am about to order a prototype of 3 to oshpark unless somebody points me and obvious mistake or a useful optimisation I can do.

Just for info, this is supposed to complement the current stereo kit.

INSERT pad goes to mnat's LOOP
LINK goes to LINK.

15 goes to pad 15, and GR goes to the ratio board.

The meter options change, instead of X/Y you connect M+ to Y on the meter and ground to the X.

This is the OshPark link http://oshpark.com/shared_projects/ADhDjUwa but of course I won't recommend that anybody tries it till I somehow test it :S





Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on December 13, 2013, 05:44:34 PM
BTW, I will have one extra of those boards... anybody wants it?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on January 09, 2014, 01:56:00 PM
Ok, I got the first prototype boards... last week. I am sending the final design to the board. BTW, this board won't be for sale, but I will put all the gerbers and design files for the grabs if somebody wants them.

(http://i.imgur.com/1xRQZYf.png?1)

Attached the schematic
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Piotr on January 20, 2014, 08:00:19 AM
Hi to all of you !



Having built a stereo rotary version of the 1176 (Mnats boards) and trying to fit it with Hairball's stereo linking pcbs, I've run in the exact same issues stated by Ricothetroll in the official Hairball thread. Stereo switch engaged nulled the ouput to almost nothing...

I've successfully rewired my unit using his drawing so big thanks to him for pointing me in the right direction and helping me understand the issue.

Here's the unit which still needs a little cosmetic work, but is calibrated and works as it should !

Thanks Rico !!!

Piotr.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: adrian on January 20, 2014, 08:04:18 AM
well done Piotr!

ce serai cool qu'on se fasse une session test un de ces 4!


Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on March 02, 2014, 09:55:56 AM
https://www.wuala.com/ricothetroll/public/Stereo-Link_wiring.gif

From what I am able to tell, according to this diagram, when hooking up the stereo link boards, the only shielded wire required is between pad 17,15,16 and the output pot. The remaining Loop, Link etc. do not need to be shielded, and may be connected using regular hook-up wire?

If shielded wire is required on the loop and link pads, where are the shields connected to? To eachother, cut away, to chassis star ground?

Ive seen many variations of the original, so I am a bit confused as to the correct shielding?

Any clarfication would be much appreciated
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on March 04, 2014, 06:22:20 PM
I realize that I have not given an update on the relay board.

The relays work, there is no motorboating (coupling between input and output) and the HPF work as well. The only thing I have not tested is the send/return sidechain, but I have bench measured it and it is ok too.

The only thing is that I am probably provide a new layout. The issue is that there is only one GND pin on the board, and that makes quite challenging nailing the grounding. It is possible, but a pain in the arse to do it properly, i'd like to save the community the nuisance.

The new board will split K101 in two connectors, one with M and GND and the other with +30V and GND.

There will be also GND pins in K103 and P103 (and you really want those if you want to do any sensible shielding)

There is something else, I don't know if anybody would care though.
Upon engaging the bypass relay, the output transformer is disconnected from the XLR, which may cause some load imbalance on the output transformer, so it may be a good idea to terminate the output xfer with a resistor.

Also, and this may be more of an issue, is that upon enabling the bypass, the input is still connected to the input xfr so you will have impedance losses compared with a loopback if the output impedance of your source is not very low. This loss is negligible on the low impedance outputs of my wife's focusrite interface, but it is of about 4dB on the 320Ohm output of the ada8824.



 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dacapitan on March 16, 2014, 07:40:08 AM
I finally finished this build, completed the calibration process fine, the unit passes clean audio, no noise etc. every thing seemed to be going fine but I have run into some problems

On both channels, when Ratio of 4 or all (slam) is selected - Meter in GR mode, the VU meter goes all the way to the far right and it seems that there is no Gain Reduction when ratio of 4 or all (slam) is selected (8,12,20 work fine) (+4 VU meter mode works fine/shows level when 4 or slam is selected)

I think this has something to do with the Ratio Swtich, but I wired it according to http://mnats.net/1176_slam_mode_rotary.html - but I must have done something wrong for it be the same problem on both channels

Any ideas of what to do, where to start? - so close but yet so far!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on April 13, 2014, 08:32:10 PM
So finally I managed to finish my dual rev D stereo with the following modifications:

- True bypass with relays.
- Addition of the super-slow attack switch and the ratio 2 (it has ratios 4, 8, 12, 20, SLAM and 2).
- Buffered metering.
- Side-chain high-pass. (with relay switch)
- Side-chain send-return. (with relay switch)
- Link mode (with relay switch)

Oh boy this has been difficult... I had to design and re-spin boards, prototype, sort out routing and grounding schemas, drill more holes than I thought possible, and solder lots of small SMD parts,... But yeah! It works and sounds great!. The feeling of actually designing even a part of it by yourself is very rewarding when it finally works :)

With the mess of routing I made I am surprised there is no noise, or motor-boating, or oscillation ( even If I know the relays help)... I have to thank mnats, mike, dan and everybody in this thread for their help and for making something like this available to everybody.

Unfortunately Purple Audio vetoed the sharing of the schematics and the gerbers of the add-in board (as it is their right), but I still have 12 (unpopulated) boards around here if somebody else wants it (but I warn, this has been the most difficult build I have ever done... oh my god the smd parts). I can also describe how I added the 2:1 ratio to the rotatory version (having 5 ratios + slam) and the simple fix that is to add the super-slow mode.

So pictures here:



My wife is really digging the combination of super-slow attack, fast release, 2:1 ratio and hpf sidechain as a master bus compressor :)

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on April 13, 2014, 08:35:17 PM
transformers and stereo boards are placed under the main pcbs, the grounding is strictly not purely star grounding but a two-point tree grounding (as I wanted to keep both boards separated). There is also a sheet of mu-metal under the right-channel.

 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: hymentoptera on April 14, 2014, 08:32:32 AM
dmnieto, why the orange drops on one channel, and WIMAs on the other? Is that just what you had on hand. or were you looking for different flavors? Why else is diff between the two channels?

Is there any different in sound at all between the two? I'm guess no since this is a stereo unit? Some of us are going out of the way to choose particular caps, especially those doing coupling duty between various stages, so I'm curious as to the what, why and how for different capactitors in the 1176.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on April 14, 2014, 04:47:14 PM
dmnieto, why the orange drops on one channel, and WIMAs on the other? Is that just what you had on hand. or were you looking for different flavors? Why else is diff between the two channels?

Oh I was just experimenting with the sound, the rest on both channels is identical. Transistors are matched within 1% of each other. Resistors. specially on the sidechain and the ratios are matched to 0.1%.
In testing, both channels differ within <0.2dB for all ratios.

Quote from: hymentoptera
Is there any different in sound at all between the two? I'm guess no since this is a stereo unit? Some of us are going out of the way to choose particular caps, especially those doing coupling duty between various stages, so I'm curious as to the what, why and how for different capactitors in the 1176.

There is a slight difference in tone actually, the right channel is a bit more forward and edgy than the left. The left one is warmer, I planned to experiment a bit more, but my wife liked that she could have such a small difference in tone available.
In any case it is so, so close that you can actually use them as a stereo pair.

I can actually do some comparisons feeding the same signal to both channels (and a rev f clone) so you can hear it. Do you have any wish-list on the kind of instrument/sound and compressor settings that you would like me to run?

 
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: hymentoptera on April 15, 2014, 10:11:35 AM
...it is so, so close that you can actually use them as a stereo pair.

nice  8)

Quote
I can actually do some comparisons feeding the same signal to both channels (and a rev f clone) so you can hear it. Do you have any wish-list on the kind of instrument/sound and compressor settings that you would like me to run?

not particularly. I was just curious is all. Thanks!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: critterkllr on April 21, 2014, 04:01:05 PM
The price to make a stereo unit using Dan's case and a mono unit using the Hairball case aren't very far apart. It ends up being $600 for single channel vs under $800 for a stereo unit.  If my end goal is to end up with two 1176s, is there any reason to not go the stereo single enclosure route? It seems so much more economical, but I'm wondering why everybody doesn't just do it?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on April 21, 2014, 04:03:08 PM
The price to make a stereo unit using Dan's case and a mono unit using the Hairball case aren't very far apart. It ends up being $600 for single channel vs under $800 for a stereo unit.  If my end goal is to end up with two 1176s, is there any reason to not go the stereo single enclosure route? It seems so much more economical, but I'm wondering why everybody doesn't just do it?

It took me a day to build the mono version, months to build the stereo :S
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: critterkllr on April 21, 2014, 04:05:55 PM
It took me a day to build the mono version, months to build the stereo :S

Yours was pretty heavily modified right?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on April 21, 2014, 06:25:34 PM
It took me a day to build the mono version, months to build the stereo :S

Yours was pretty heavily modified right?

To some extent, true. But what I want to make clear is that is far more complicated to build the mono than the dual as the mono comes neatly packaged and ready, and there is much more planning in the stereo version
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on May 30, 2014, 12:31:40 AM
Hey all,

Built a mono Rev A from Hairball last fall and it came out great.  Now I'm jumping in with both feet and building two stereo Rev A units and one stereo Rev D - just got enclosures from Dan, boards from mnats, and the stuff from Hairball is in the mail.  I'm putting together a massive Mouser order for most of the remaining bits and I have a question about which rotary switches to get.

I found the Lorlin 4-pole 3 position switch for the metering selector but for ratio, the Alpha 5-position 2-pole that I see on the mnats site and elsewhere (SR2921F-0205-19R0B-E9-S-W) is out of stock at Mouser til late July, and I'm hoping to get these well on their way before then.

Any suggestions on a good alternate that you folks know of?

thx,
Aaron
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on May 30, 2014, 02:40:51 AM
Use the six positions one

http://www.mouser.com/ProductDetail/Alpha-Taiwan/SR2921F-0206-19R0B-E9-S-W/?qs=sGAEpiMZZMvNbjZ2WlReYnqYHrQfuERsVYNhUxQIdK0%3d

You can even wire a 2:1 ratio on the last one as I did...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on May 30, 2014, 03:00:45 AM
Interesting, now that you mention it I recall seeing that some other DIY versions used a 6-position switch but I hadn't considered it for use with Dan's cases.

The 2:1 option seems cool.  I searched through your posts here and couldn't find details on how you executed that - is there somewhere you explained it or would you mind giving away the particulars here?  I assume it's relatively simple in terms of picking appropriate resistor values for the associated switch position, yes?

Forgive me if this falls into general 1176 discussion rather than stereo-specific.  I'm sure I'll be spending some significant time in this thread!
Title: Realistically, can I do this?
Post by: thunk on June 09, 2014, 11:53:23 AM
Hello all.

I'm an intermediate builder at best.  I've built some SCA stuff, and rewired guitars and such, but nothing more complicated than that.

I'm a slow, careful and methodical builder, and a competent solderer, and I'm confident I could build a Hairball Complete FET Compressor Kit.

But what I *really* want to build is the Stereo FET Compressor.  It's just that it's a little bewildering.

Here are some potential issues I see:


But despite all that I still want to jump in and build the Stereo unit.  Partly because I mostly want to print stereo buses through it.  And partly because the challenge is appealing.

So what would you good people advise?  Am I getting in way over my head?

(On a side note, I would *happily* pay for a complete Stereo FET Kit with an official assembly guide, and I'm sure many others would too.  Maybe Hairball would consider offering this in the future?)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on June 09, 2014, 05:21:01 PM
Hey thunk - my $.02:

Build two of the mono Hairball units, get them each working well, then do the stereo link.  It will cost more (about $200-300) and take up two more rack spaces, but it gets around the aspects of the stereo build that are giving you anxiety.  Doing those will help give you the confidence and experience to take on something more complicated and challenging like the 2-1176.

FWIW, if you really do want to go ahead with a 2-1176 buid, Dan lists some suggested part numbers on the Collective Cases page for his stereo 1176 enclosure, most specifically the XLR jacks, along with a couple other things.  For the rest, I started with a Mouser cart for the Hairball mono version, doubled it, then removed the unnecessary power supply parts.  It takes some careful reading and understanding of the schematic and PCB to make sure you are editing the BOM correctly.  Additionally, some of the Mouser items in those carts are currently on backorder, so you have to search Mouser or elsewhere for substitutes.  For example, I had to get NOS 2N3053 transistors from an eBay seller because Mouser and a few other sources wouldn't have them back in stock for months.

Then you also need to find the parts for the mnats dual PSU, knobs, toggle and rotary switches, pilot lamp parts, and other assorted bits.  Some of those things I was able to choose based on my previous experience with electronics, others I found by combing through the copious amount of forum posts here and elsewhere regarding the stereo build.

I would totally share my Mouser carts for the stereo Rev A and Rev D (I'm building both right now) but I haven't proven to myself that they are complete and without fault, so I am not confident offering them to others at this point.

Best of luck to you!  I'm sure I too will be posting some questions about my builds here soon enough.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: thunk on June 09, 2014, 07:34:23 PM
Thanks velo-hobo -- that's incredibly helpful!  I will probably do as you suggest and start with two mono units.

And your info on parts for the 2-1176 is crucial.  That's the sort of consolidated info I've found difficult to locate.

There is a bit of an information gap between step-by-step all-parts-included kits and the big wide world of DIY-from-scratch.  Those of us looking to make the jump can find it difficult to find a foothold.  That, or it's all out there, and I'm just impatient, and need to keep digging and absorbing knowledge :)

Please do keep posting as you make progress.  I'm sure it will come in handy to others like myself.

Edit:  And I'd love to see your 2-1176 A/D Mouser carts whenever you're comfortable with them.  Even if they're not perfect now, with a disclaimer they could be a great starting point for others.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: tonycamp on June 24, 2014, 10:29:06 PM
So finally I managed to finish my dual rev D stereo with the following modifications:

- True bypass with relays.
- Addition of the super-slow attack switch and the ratio 2 (it has ratios 4, 8, 12, 20, SLAM and 2).
- Buffered metering.
- Side-chain high-pass. (with relay switch)
- Side-chain send-return. (with relay switch)
- Link mode (with relay switch)

Oh boy this has been difficult... I had to design and re-spin boards, prototype, sort out routing and grounding schemas, drill more holes than I thought possible, and solder lots of small SMD parts,... But yeah! It works and sounds great!. The feeling of actually designing even a part of it by yourself is very rewarding when it finally works :)

With the mess of routing I made I am surprised there is no noise, or motor-boating, or oscillation ( even If I know the relays help)... I have to thank mnats, mike, dan and everybody in this thread for their help and for making something like this available to everybody.

Unfortunately Purple Audio vetoed the sharing of the schematics and the gerbers of the add-in board (as it is their right), but I still have 12 (unpopulated) boards around here if somebody else wants it (but I warn, this has been the most difficult build I have ever done... oh my god the smd parts). I can also describe how I added the 2:1 ratio to the rotatory version (having 5 ratios + slam) and the simple fix that is to add the super-slow mode.

So pictures here:



My wife is really digging the combination of super-slow attack, fast release, 2:1 ratio and hpf sidechain as a master bus compressor :)

Hi Dmnieto, seriously killer build man! i would love to hear about the 2:1 and super slow attack?

Thanx
T
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on July 17, 2014, 10:07:31 PM
Regarding super-slow attack time, quoting dmnieto from post#139:

Quote
1. I am adding the super-slow attack mode by using the SPDT switch in the attack pot to either have a 0.022uF (max 0.8ms time) or a 0.22uF (~8ms attack time)

Since the collectivecases stereo rotary switch version places the GR-off mode on the meter switch, the switching capability of the attack pot as supplied in Hairball BOM/Mouser cart is superfluous.  Using the switch on the attack pot to enable super-slow mode is a pretty brilliant idea, since the switch is located at the slow end of the dial and the cap (C27) which I believe affects attack time is right there on the pot.

Correct me if I'm wrong, but my interpretation of this approach is that the super-slow mode attack time is tunable by altering the capacitance of C27.  Does larger value=slower time? (furthermore, seems like it doesn't necessarily have to be .22uF for ~8ms, could be smaller for shorter time?  Does it work that way?)

Still not sure how the 2:1 ratio is implemented, but I haven't really spent any time thinking about it - I suspect it's a matter of picking the proper resistor values associated with the switch position?  Thus it may be possible to extrapolate those from the known R values for the other ratios.

At this point I have the cases assembled, PSU boards stuffed and tested and am headed towards stuffing the main PCBs.  Going to worry about the rotary switches after that.  Though it's always good to think ahead when one is considering implementing mods!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on July 18, 2014, 01:34:09 AM
Also, just dug this thread up:  http://groupdiy.com/index.php?topic=47196.0 (http://groupdiy.com/index.php?topic=47196.0)

Wherein implementing a 2:1 ratio is discussed, but in the context of replacing the 4:1-8:1-12:1-20:1 ratio set with 2:1-4:1-8:1-20:1, specifically in the Rev D circuit.

I'm interested in adding 2:1 to the typical set of ratios, in both Rev A and Rev D, which I think means different resistor values for each version.

Mostly because I had to buy a 6-position switch due to mouser being out of stock of the 5 position switches at the time I placed my order, but hey, 2:1 sounds pretty dang useful, especially with slower attack times.  5-position switches should be back in stock early August, in case this doesn't look like it will pan out...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: BenHer on July 18, 2014, 07:15:14 PM
Hi everyone,
I'm building a 2 channel unit in Dan's case with Hairball/mnats parts and only 20:1 ratio works. The other ratios pass audio but its quieter with no compression. I'm getting 0.147 V at pad 22 @ 10db reduction 20:1, and 0 volts at any other ratio. I'm using a rotary switches wired for "slam mode". Both channels are doing the same exact thing. I've checked the switch wiring about 10 times. It looks right when compared to the mnats pics. Any help would be much appreciated.
Thanks
-Ben
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on July 24, 2014, 02:00:42 AM
Also, just dug this thread up:  http://groupdiy.com/index.php?topic=47196.0 (http://groupdiy.com/index.php?topic=47196.0)

Wherein implementing a 2:1 ratio is discussed, but in the context of replacing the 4:1-8:1-12:1-20:1 ratio set with 2:1-4:1-8:1-20:1, specifically in the Rev D circuit.

I'm interested in adding 2:1 to the typical set of ratios, in both Rev A and Rev D, which I think means different resistor values for each version.

Mostly because I had to buy a 6-position switch due to mouser being out of stock of the 5 position switches at the time I placed my order, but hey, 2:1 sounds pretty dang useful, especially with slower attack times.  5-position switches should be back in stock early August, in case this doesn't look like it will pan out...

I did keep the 1:2 myself...

You just need to split the resistors on the 4:1 ration on each of the series and wire the intermediate position to the additional switch position=> substitute the 150 for a 68then 82 ohm and the 47k in 20K then 27K
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on July 24, 2014, 02:04:22 AM
Using the switch on the attack pot to enable super-slow mode is a pretty brilliant idea, since the switch is located at the slow end of the dial and the cap (C27) which I believe affects attack time is right there on the pot.

Correct me if I'm wrong, but my interpretation of this approach is that the super-slow mode attack time is tunable by altering the capacitance of C27.  Does larger value=slower time? (furthermore, seems like it doesn't necessarily have to be .22uF for ~8ms, could be smaller for shorter time?  Does it work that way?)
thanks and yes :). The time constant is R*C... higher C => higher attack time. It works quite linear... I have even use 2.2 and 22uF for 80 and 800ms... but at those levels... I dont think it qualifies as a 1176 anymore...

2.2uF is quite cool though... 80ms is a sweet value for me
Quote
Still not sure how the 2:1 ratio is implemented, but I haven't really spent any time thinking about it - I suspect it's a matter of picking the proper resistor values associated with the switch position?  Thus it may be possible to extrapolate those from the known R values for the other ratios.

At this point I have the cases assembled, PSU boards stuffed and tested and am headed towards stuffing the main PCBs.  Going to worry about the rotary switches after that.  Though it's always good to think ahead when one is considering implementing mods!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: ferrochrome on August 05, 2014, 06:41:27 PM
dmnieto, I have a question since you figured out the external sidechain part on your relay board.
I built this stereo rev D a long time ago. Great unit, but I'd like to add external sidechain input. How would you go ahead and implement that into the stereo linked rev D?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 06, 2014, 05:40:42 PM
Hi all,

I have just put together a stereo 1176 with the link pcbs from hairball but getting some strange results.byave wired up per instructions but link switch cuts all audio.
Left channel doesn't seem to pass audio, output control doesn't work but input does as I can hear a faint bit of signal.
Right hand channel passes audio but doesn't seem to compress.
I'm thinking of pulling out the link pcbs again and rewiring just to check each channel does work correctly as it did before the install of the link pcbs.
The one weird thing which is quite cool is when I turn up the input and output on th right hand channel which works the LEDs dim!! Looks very retro!
Obviously need to sort this out as well as this shouldn't be happening.

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 07, 2014, 05:09:15 AM
Hi,

Right I'm a little confused now, I've taken out the hairball link pcbs and put everything back to how it should be wired with a balancing board as balanced output.
I have led on vu meter wired with 100r resistor on 30v power side and when I give input signal and turn up input and output the led dims as I increase.
Have checked voltage and voltage drops from 30v to 15v as input and output increased? Is this the vu meters drawing power?
This only happens on GR, nothing seems to happen when on VU, no compression I mean.
Attack and release seem to be working correctly, along with meter switch.
Any ideas what I'm missing here?

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 07, 2014, 07:32:31 AM
Hi,

Ok progress, right hand channel now compressing and no flashing lights anymore!!!
Seems the only thing I changed was the lead coming from the pcb balanced output into the balancing board input, reverse it?
I did have the output pot and the the output pot to the pcb round the wrong way so I've changed that as well
Gonna look at left channel now, get them both working then put in the link pcbs again.

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 07, 2014, 08:30:08 AM
Hi,

Got it back working both channels now, setting up both channels then I'm gonna attempt to put the link again!!!

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 07, 2014, 11:40:08 AM
hi,

in GR meter works fine but when in VU nothing happens to the meter? its all compressing but not quite the same on both channels, as channel one does sound much better and has better gain structure.
any clue to why meter dont work in VU mode?

regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on August 07, 2014, 04:37:31 PM
(http://stagefrightrecords.com/21176.jpg]http://stagefrightrecords.com/21176.jpg)The link PCB is not so essential. Get you 1176's working properly first! Then link them. personally I linked pin 7 as cheat on my link switch. I use them on lots of stuff including drum overheads. Got snare and high hat on one side. And ride and Floor Tom on other. Like that will actually need A tight link.... LOL! Mnats compressors rock.
http://stagefrightrecords.com/21176.jpg
 (http://stagefrightrecords.com/21176.jpg)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on August 07, 2014, 05:00:29 PM
Thanks! if ya build it right it rules! TY Mnats. Sorry image is all juncked up...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 08, 2014, 12:07:33 AM
Hi,

Stage fright I can see from your build you have the all button on your switches, is this possible using a lorlin switch? I know how to wire it up with a DPDT switch, just wondered if there was a Lorlin mod.
Still need some answers on why meter doesn't respond in vu mode?

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on August 08, 2014, 12:55:24 AM
Mako gives everything you can ask for on his site.Try this: http://mnats.net/1176_slam_mode_rotary.html
I did use A lorin switch for this tho.
Been A while. Been workhorse for years! TY Mnats!

John
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Stagefright13 on August 08, 2014, 01:14:07 AM
Just look at schematic all mine will go into slam mode. By buttons or switches. Same thing. http://www.stagefrightrecords.com/P1020378.JPG (http://www.stagefrightrecords.com/P1020378.JPG)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 08, 2014, 03:53:03 AM
hi stagefright,

i dont think its as easy as looking at the schematic dude!!! lol

regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 08, 2014, 01:35:27 PM
hi all,

have tried the setup procedure and cant get VU mode meter anywhere? so its definitely nothing i'm doing wrong in the setup.
both channels will calibrate in GR mode but nothing in VU mode?
anyone got any ideas?

regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Spencerleehorton on August 11, 2014, 07:33:49 AM
Hi all,

As always a couple of wrong resistors and a bad chip in the balancing board so far on one channel. That channel sets up fine now, just got try and figure out  what's happening with this other channel.

Regards

Spence.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 26, 2014, 10:08:50 PM
I did keep the 1:2 myself...

You just need to split the resistors on the 4:1 ration on each of the series and wire the intermediate position to the additional switch position=> substitute the 150 for a 68then 82 ohm and the 47k in 20K then 27K

Thanks for that info dmnieto - I knew it must be relatively simple, and looking at the schematic that makes a lot of sense.  You are referring to the Rev D schematic, yes?  In the Rev A schematic, the first resistor on one side of the series is 120ohms rather than 150.  I would guess that a 56 and a 62 would be appropriate substitutions in this case.

How did you wire your SLAM! mode then?  From reading elsewhere (and looking at the schematic) it seems it's really just the 4:1 and 20:1 buttons that are creating the effect.  Did you just wire it the same, 4:1 and 20:1 switches closed in that mode?

Also, the rotary switch ratio boards that mnats provides are designed for the 5-way switches.  I think there will have to be some clever wiring going on in order to make the 6-way work with the existing boards and the 2:1 ratio.  I assume since you designed your own board that this wasn't an issue for you.

Almost makes me want to give in and order the 5-way switches, but I'm still populating the PCBs so have some time to ponder it...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 27, 2014, 05:09:54 PM
I am also very curious as to how to have 2:1 and all those ratios including slam on a 6-way switch with the ratio switch board supplied by mnats?
I have bought Dan's case, boards, and a 2-1176 hairball kit. I just need mouser supplies. Is anyone implementing a passive switchable high-pass filter in their builds? Would this be inserted after the ratio switch, but before c17 with a simple spdt toggle switch incorporating a cap, resistor, and ground wire?

I will be installing bypass relays and super slo-mode on the attack switches.

I would like to here from others about where in the circuit to implement a switchable high-pass filter and what values work well for certain cut-off frequencies? I am thinking 120hz.

How to implement 2:1 4:1 8:1 12:1 20:1 and slam with 6-way switch on mnats 5-way switch board if it's possible?

Thanks in advance for anyone willing to shed some light on these mods.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 27, 2014, 05:31:47 PM
Yesterday evening on my way home from the shop I think I figured out a way to add the 2:1 ratio and use a 6-way switch with the mnats ratio board and still use slam mode.

Still need to prove it in practice, though basically you stuff the board and wire up the switch as shown on the mnats pages, BUT replace the 47k and 150 resistors that are associated with the 4:1 position with two resistors in series for each that add up to those values (or close) as mentioned in the above post by dmnieto and the other thread I referenced about 2:1 4:1 8:1 20:1 mod.

Physically, each of those resistors will have one leg in the pcb thru-hole and the other floating free.  The free ends would be tied together and this junction is the location to tie in the 2:1 switch.  The ratio board traces need to be studied to determine which pad goes to which resistor since they are not of equal value.

Using Dan's case, the 2:1 switch position would be at the extreme counter-clockwise end of rotation.  All the leads from the switch terminals go to the ratio board as shown by mnats except leads from the 2:1 terminals go to the aforementioned resistor junction.

Slam mode is still wired up as shown in the mnats pics, essentially closing the 4:1 and the 20:1 switches simultaneously, and the pairs of resistors in the 2:1 mod mimic the stock arrangement.  Thus Slam mode should work as though the 2:1 mod doesn't exist.

Again, this is my hypothetical solution - still populating the main PCBs (just finished all those resistors!), but I think this is the method I will attempt unless someone can find fault with it.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 27, 2014, 08:50:04 PM
Yes, I was figuring resistors would have to be soldered directly to the switch for the 2:1 position, and keep the 2:1 position out of the 4:1 thru 20:1 slam loop. Sounds about right. I just don't know without tinkering as I haven't got my build under way just yet. So, the extra 2:1 resistors will be piggy backing on the 4:1 resistor location on the board, but the 2:1 resistors legs will only be soldered on one leg of the 4:1 resistor board location. With the other 2:1 resistor legs soldered directly to switch?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 27, 2014, 09:06:35 PM
So, the extra 2:1 resistors will be piggy backing on the 4:1 resistor location on the board, but the 2:1 resistors legs will only be soldered on one leg of the 4:1 resistor board location. With the other 2:1 resistor legs soldered directly to switch?

The two stock 4:1 resistors are split into the four news ones.  2:1 switch connects to half of each pair, 4:1 runs through both pairs.  If you look at the schematic, imagine R22 and R58 are each split into two resistors in series that add up to their original values.  The 2:1 switches connect at the junctions between these new pairs.

Physically the series pairs of replacement resistors need to connect to the same spots on the ratio board as the stock 4:1 resistors do, and the 2:1 switch terminals connect to the junction between those.  That way, 2:1 switch closure sees only the first half of each pair, 4:1 sees both.  Whatever physical implementation makes most sense to you is the way to go.  I'll probably post a picture once I get one put together.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 27, 2014, 10:36:42 PM
So the 2:1 switch position will be right in between the new r22 r58 series pair of resistors. So r22 is 47k, r58 is 150.
Example: r22 in series
23.5k < 2:1 ratio switch position < 23.5k < 4:1 = 47k

Same for r58

75r < 2:1 ratio switch position < 75r < 4:1 = 150r

I need pictures.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 27, 2014, 10:51:45 PM
Right, except good luck finding two 23.5k resistors!  If you take a look at the thread I mention in post #166 (http://groupdiy.com/index.php?topic=47196.0) you'll see that they've come up with some new resistor values to get the ratio boards to function like the 1176ae (2:1 4:1 8:1 20:1)

Seems like success was reported by some folks on that thread using that scheme to achieve 2:1 (or something close to it), and as well by dmnieto here on this thread.  Both instances report using a 20k and 27k in place of R22 and a 68ohm and 82 ohm in place of R58, although user Kingston suggests using a 100ohm in place of the 68ohm (at least I think that is what they are suggesting - hard to tell) to keep 2:1 from being louder than the other ratios.

R58 and the associated chain of resistors apparently control make-up gain after compression?  You can see on the schematic that this half of the ratio circuit interacts with the GR Control Amp, which seems to jive with that concept.  If you were to use a 100ohm for 2:1, then I would think a 47ohm would be a good one to put after it to get 4:1 to work normally.  Might try that out myself.

Disclaimer, I am not an electrical engineer, just familiar enough with this sort of thing to muddle my way through it and possible come up with some bad ideas.

Also, I realize this is sort of getting away from stereo-specific build issues, but there's already a ton of info in this thread on the ratio mod topic.  Moderator's call as to whether it all belongs elsewhere...
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 27, 2014, 11:14:46 PM
Right on ya those resistor values were arbitrary. Have a look at igor's 1176 schematic http://groupdiy.com/index.php?topic=43338.0 it shows 2:1 and how to implement the 100hz high-pass filter before the side chain. I will have to tweak the auto gain resistor by ear with a hand full of different resistor values to get a approximation.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 27, 2014, 11:26:28 PM
Thanks for pointing out that thread, I hadn't seen it yet.  Can you point to the specific post #'s that reference the 2:1 ratio?  It's a huge thread, I'll read the whole thing at some point but for posterity it would be nice to have a direct link here in this thread.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 27, 2014, 11:39:15 PM
At the beginning of the tread click http://twin-x.com/groupdiy/thumbnails.php?album=417 and view docs download zip and look at the schematic.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 27, 2014, 11:44:53 PM
Ah it's in an attachment, that explains why search didn't find it.  Thanks for the heads up.  Good luck with your build, I'll post photos of my ratio assembly once I get it together.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 29, 2014, 04:27:35 PM
Looking at the schematic and build thread on Igor's 51x-F76, it would seem the sidechain HPF is an RC scheme using a 56k resistor to ground and a .022uF cap in series between the ratio and the output.

Igor's schematic says 10nF/.01uF but it and the BOM are marked TBD, photos of actual builds show he has supplied a 22n/.022uF cap with the kits.  Using this calculator (http://sim.okawa-denshi.jp/en/CRhikeisan.htm) it sets the cutoff at about 130Hz. Seems like I see people aiming for the 80-100Hz range, which would indicate a .027uF or .033uF cap (larger cap value=lower cutoff frequency)

Can anyone who's done a HPF mod on the hairball 1176 report on how they achieved it and at what cutoff frequency for the sweet spot?  dmnieto?  I suppose I could just try when I get to that point since it is a very simple mod to experiment with, but reports from someone who's already done it would be helpful.

[Edit - I did some more reading and I'm realizing that the desirable cutoff frequency is heavily dependent on program material - but for a single frequency option, maybe something between 100-200Hz is best? Thus .018 or .022uF might be the way to go.  Will have to experiment!]

I think I will use the bypass switch location on Dan's case to implement the HPF since I don't plan on putting together a relay-based true bypass for my current builds.  I already stuffed the faceplate with a DPDT switch too so it is ready to go.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on August 29, 2014, 08:54:11 PM
I wouldn't go any lower than 120hz on the high-pass filter because you want the kick and bass to bloom, but below 200hz because you will still want to compress the low-mids and snare. I might socket those and play with the values when I get my build going. It will probably be another month before I can purchase the mouser bits. I will use the capi 24 volt relays which worked well in my last build they are cheap you ought to implement them in your build. It's a great way to a-b your signal to make sure you are actually making an improvement and to check gain staging. Here is the link to the relays I use. http://classicapi.com/catalog/product_info.php?cPath=102&products_id=389
Thanks for the info on the hpf calculator.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 29, 2014, 09:01:54 PM
Yep, I realized that about the HPF after reading some more and seeing what was typical out in the world.  Makes sense to me.

Thanks for the heads up about those relay kits, I didn't realize anyone was doing a kit that is that small, simple and cheap.  Might actually go for that and add another switch hole for the HPF.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on August 30, 2014, 02:24:54 PM
I did keep the 1:2 myself...

You just need to split the resistors on the 4:1 ration on each of the series and wire the intermediate position to the additional switch position=> substitute the 150 for a 68then 82 ohm and the 47k in 20K then 27K

Thanks for that info dmnieto - I knew it must be relatively simple, and looking at the schematic that makes a lot of sense.  You are referring to the Rev D schematic, yes?  In the Rev A schematic, the first resistor on one side of the series is 120ohms rather than 150.  I would guess that a 56 and a 62 would be appropriate substitutions in this case.

How did you wire your SLAM! mode then?  From reading elsewhere (and looking at the schematic) it seems it's really just the 4:1 and 20:1 buttons that are creating the effect.  Did you just wire it the same, 4:1 and 20:1 switches closed in that mode?

Also, the rotary switch ratio boards that mnats provides are designed for the 5-way switches.  I think there will have to be some clever wiring going on in order to make the 6-way work with the existing boards and the 2:1 ratio.  I assume since you designed your own board that this wasn't an issue for you.

Almost makes me want to give in and order the 5-way switches, but I'm still populating the PCBs so have some time to ponder it...

You can use the same 6 position rotary switch (instead of the 5 position one) from mouser. They are almost the same.

I used the same rotary pcbs as everybody else... I just cut the trace that joins the pad 7 with 24 (If I remember properly) because it predates one of the holes for the rotary switch. Then in the pad for the 150 and 47K resistors I put two series resistors (80+60), (20K+27K) and i wired the middle point to the free holes of the rotary switch pcb.

Other than the fact that the positions are 4:1 8:1 12:1 20:1 SLAM and 2:1, it works very well.

Something else is that because of its configuration the 2:1 threshold is much lower than 4:1, almost 12 db lower... so you need to control the input properly
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dmnieto on August 30, 2014, 02:27:31 PM

Can anyone who's done a HPF mod on the hairball 1176 report on how they achieved it and at what cutoff frequency for the sweet spot?  dmnieto?  I suppose I could just try when I get to that point since it is a very simple mod to experiment with, but reports from someone who's already done it would be helpful.

[Edit - I did some more reading and I'm realizing that the desirable cutoff frequency is heavily dependent on program material - but for a single frequency option, maybe something between 100-200Hz is best? Thus .018 or .022uF might be the way to go.  Will have to experiment!]

I think I will use the bypass switch location on Dan's case to implement the HPF since I don't plan on putting together a relay-based true bypass for my current builds.  I already stuffed the faceplate with a DPDT switch too so it is ready to go.

I used a two pole active sallen-key in my design... at 120Hz if I remember, my wife sometimes swap the capacitor to get it from 120Hz to 160Hz
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on August 31, 2014, 02:22:12 PM
Thanks for the ratio switch and filter info dmnieto!  man, I learn some new stuff every time I check updates to this thread.

I may still try the ratio switch configuration I described above.  It doesn't use the extra pads on the ratio PCB,  but I think it will place the 2:1 position next to the 4:1.  OCD a bit I guess.

Any thoughts on passive RC filters vs. active Sallen-Key?  What made you choose the active approach?

I was thinking it'd be cool to add another rotary switch to enable different frequencies for the HPF, but that seems like it would easier to do with a simple RC filter.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 02, 2014, 09:51:30 PM
Check it out heres how mako does 2:1 on his new 500 series 1176. http://mnats.net/files/FET-D500.pdf

Looks like a series of 22k & 27K to get close to the 47K and 68r & 82r to get the 150r for the 2:1 ratio
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on September 02, 2014, 10:23:29 PM
Awesome, yeah hairball just dropped their 500-series FETs today (developed by mnats and the same thing you link to)

Thanks for posting the pdf link, I was hoping to check out the schematic when the hairball build guide was released in two weeks but now I don't have to wait.  Good to confirm multiple circuit designers are using the same component values to achieve 2:1.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 05, 2014, 08:00:01 AM
I am searching for the alpha 6 position 2 pole 2 deck switch to add a 2:1 ratio to my build Manufacturer Part #: SR2921F-0206-19R0B-E9-S-W. Seems mouser has stopped carrying this piece. Does any one know where an alternative place to buy a couple of these, are someone that has a few laying around they want to move?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on September 05, 2014, 01:08:17 PM
That's a bummer! Weird that they don't have a lead time listed, usually when something is out of stock they do (the 5-position version of that switch was backordered til just a few weeks ago)

Also I'm not seeing that Alpha switch anywhere else on first glance (not at digikey or newark or in a web search)

Maybe look at this one from Electroswitch, also on Mouser: C4D0406N-A

Kinda expensive but it looks like it has the same important bits - 6 position, 2 decks, 2 poles per deck, 30° index angle

There is a Grayhill available from Mouser too but it appears to be the PCB-mount rather than panel-mount version.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 05, 2014, 02:56:05 PM
Yep, I think they must have discontinued the 6-way, but I will contact mouser anyway to see if they can order 2. I ordered all the other bits for my build along with the the 5-way switches if the 6-ways don't pan out. Time to fire up the solder. The power switch is dpdt right? Here's the one I ordered it's 20 amp, but I don't think that's a problem. Mouser Part #: 506-AWTN1504. I'm just confused about the switch function thing where you can choose on off on, on none on, on on ect, ect.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on September 05, 2014, 03:20:13 PM
Actually, looks like Stew-Mac still has 'em, but with a knurled shaft as opposed to smooth.  No big deal I suppose.  I bet other guitar parts retailers might have them too, look for 6-position 4-pole rotary switches, I think Alpha is a common supplier for these types of places.

http://www.stewmac.com/Pickups_and_Electronics/Components_and_Parts/Switches/Rotary_Switches.html (http://www.stewmac.com/Pickups_and_Electronics/Components_and_Parts/Switches/Rotary_Switches.html)

It's the 6-position 4-pole, and looks like it is the Alpha.

EDIT: Allparts seems to have the smooth-shaft version, with a pointer knob included:

http://www.allparts.com/EP-0920-000-6-position-Rotary-Switch_p_1345.html (http://www.allparts.com/EP-0920-000-6-position-Rotary-Switch_p_1345.html)


--------------

Power switch is DPDT, the one you reference should work fine, 20-amp is sufficiently over-spec! Just check the physical dimensions to make sure it won't crowd or interfere with anything else on your faceplate.  The power switches I bought are a little big and I barely got them to fit to my liking next to the stereo link and bypass mini-switches (in dan's cases)

You wanna switch both hot and neutral just in case the wall circuit you are plugging into has them reversed.  Check the mnats 1176 wiring guide for info on how to do it up right:

http://mnats.net/1176_reva-d_hairball_wiring_power.html (http://mnats.net/1176_reva-d_hairball_wiring_power.html)

(As he shows, the transformer leads go on the center/switching terminals - if you put the supply voltage on the switching terminals instead, you'd have live power on the unused terminals in the off position, which would constitute a shock hazard. )
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 05, 2014, 05:59:35 PM
With that ratio switch you suggested I guess it doesn't matter that it has 4-poles you could just solder the poles together to make a 2-pole 6 position switch with 2 decks for wiring the slam function. The pcb is set up for 2-pole on the ratio, so you would have to accommodate with a 4-pole switch. I assume you could solder the lugs together on a multi-pole switch to make a 2-pole. I going to get a quote from mouser first on the alpha. Thanks for the help.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on September 06, 2014, 03:17:21 PM
The Alpha switch from Mouser could be considered a 4-pole - 2 decks, 2 poles per deck.  The Allparts one looks like pretty much the same exact thing, so it should be fine to wire up as shown in Mako's rotary switch wiring guide.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 10, 2014, 05:25:33 PM
Bought the Allparts 6-position alpha switches. They are just like the 5-way that mako recommends with the extra position. Should work out great for the extra ratio. Thanks velo-hobo for helping me find the parts. I had to order a couple more things from mouser, but I believe I have every part to build my 2-1176 with various mods. I do want to hear from other members about stepped pots for input and output for better stereo tracking. I have been looking at the elma's. I would need to make a bridged t-pad attenuator for input, but I think 1db steps might be to much for input. Outputs could be more like 2db steps. It my be eaiser to just do stepped outputs and try to match input as best as possible with the variable t-pad's.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 11, 2014, 10:41:44 PM
Here is a diagram of the 2:1 ratio mod I came up with for the 6-position Alpha switch. If you are looking at the back of the pcb and pot it should be noted that to have the 2:1 next to the 4:1 instead of placing it after the slam position. The pot will have to be rotated one position clockwise relative to the pcb board to mimic Mako's Slam pictorial, as well as his jumper positions being soldered one position over clockwise http://mnats.net/1176_slam_mode_rotary.html. By shifting the pot one position relative to the ratio pcb board you effectively give you the 2:1 switch position full ccw next to the 4:1. As long as you make sure the wiper on the pot lines up with the position in the picture you should be fine.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on September 28, 2014, 02:50:03 PM
Completed build! Features 2:1 ratio, 130 hpf, capi bypass relay, link boards, and slo-mode ala 1176 ae, but with one exception instead of the 10 mS slow attack of the ae version, I used a cap for a 30 mS attack time. This will be comparable to the slowest attack setting of an ssl buss compressor.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on October 02, 2014, 07:14:35 PM
Slick, what are those CAPI relays zip-tied to?  I got them and realized they're meant to plug into another PCB (custom or otherwise intended for those) - doh, no provision for mounting to standoffs included.  I might 3D print some little brackets to hold them (have a makerbot at my work and would be a cool excuse to use it for something functional!)

Also, would love to see a close-up photos of your ratio switch assembly, but that might be hard now that they're in place!

I have a slightly different idea for the ratio scheme, will post photos once I get it put together.  Been very busy with work and other stuff so not making much progress on my builds at the moment.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 02, 2014, 08:13:22 PM
I bought these for the relays http://www.mouser.com/Search/ProductDetail.aspx?R=PP1S-S10-Xvirtualkey64400000virtualkey644-PP1S-S10-X. Buy 4 and screw 2 together for each set of relays to make a relay holder, and then bolt to case. Remember when you bypass input to output on the first relay the second one is to take the output transformer out of circuit so you don't have loading when in bypass on the output. First relay as follows: input xlr goes to "O" pins. "A" pins goes to t-pad, and "B" pin goes to output xlr. For the second relay take the red and blue wire from the output transformer and wire to "O" pins.  "A" pins will go to output xlr, and the B pins will be empty, so in bypass the transformer will be out of circuit. Here's some photos of ratio switch. It's IMPORTANT you slide the M.Nat's slam wiring scheme down one position are else you will be left with 2:1 clockwise after slam. Check out my picture above of the ratio layout and you will see what positions goes with which ratio as you turn the rotary switch. It took me a night to wrap my head around it, but it works great. What I did was turn the rotary switch to the furthest clockwise position which will be your slam position you will need to bridge those decks as in M.Nat's pictorial and the 4:1 decks. Leaving 2:1 out of loop like I did or you could wire the 2:1 in the slam loop there's no rules, but it sounds like slam to me how I set it up. Here's some photos.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 02, 2014, 08:24:54 PM
See how you have to turn the whole switch over one position to address the new 2:1 position relative to the pcb.  Instead of straight up and down as in M.Nat's rotary wiring guide. I have both 5-way and 6-way switches an the extra position on the 6-way is clockwise instead of counterclockwise relative to the 5-way switch. So to compensate you must turn the whole 6-way switch relative to the pcb board to achieve 2:1 @ the counterclockwise position. Here's a photo of the slo-mode switch. With caps on the attack switch you will have to bridge the c27 .022uF position on rotary pcb.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: velo-hobo on October 02, 2014, 08:49:15 PM
Thanks for that - didn't realize I needed a pair of relays for each channel, but makes sense to take the OT out of circuit too.  I'll need to buy some more from Jeff.

Still might make some 3D printed brackets but we'll see.  I haven't gotten to thinking about layout yet, just been stuffing all my boards and gathering parts for my mods.  I'm building 3 stereo units so probably a good idea to move slowly.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 13, 2014, 01:02:16 PM
I had a better idea of how you could use the capi relays with the headers mounted on some vector board and just solder some flying leads or connect the header underneath the vector board to some barrier strip terminals to connect your shielded balanced wire to. This approach might be more elegant than brackets.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Janalex on October 16, 2014, 08:29:09 AM
Hi all,

My first post on the forum. I'm going to build one of these units and am about to order the parts. Has anyone compiled a complete bom for this project?  I was going to start by ordering the stereo bundle kit from hairball,  case from collective cases, 2 mouser rev d carts, a pair of meter and ratio boards, and pair of mnats rev d boards. We were going to build the power supply on each board instead of the dual supply. I think this only leaves the rotary  switches and all the pots to add to the mouser kart... Can you please confirm the part numbers for all the pots and rotary switched as well as the knobs?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 18, 2014, 10:25:06 AM
Hi, Janalex

Welcome to the forum, first off there are a few things on the mono bom provided by hairball that are not added for a stereo build, such as switches and rotary knobs, power indicator lamp, lamp bulbs, transistor socket's, shrink wrap, wire if you don't have it, and lamp and led resistors. First, I would like to ask you, do you intend to run the 2-1176 stock or do you intend to hot rod-it. This will determine the parts one will need. I strongly recommend reading through this thread to get a grasp of options available. Do you intend to link them, or run them dual mono? Why not have one power supply? Have you used mouser before? Is this your fist diy project? Do you have this http://mnats.net/files/1176LN_REVD_V2.2_DOC.pdf?
Any how you are going to need a power switch which is pretty important that's not listed on the mono bom. Dan's case is pretty narrow between 2: link, and bypass dpdt switches that leaves a bit of room for the power switch. I had to go into the c&k datasheets to figure out the one that would fit. You will need to learn how to decipher component datasheets and the parts # schemes. Are else you will end up buying a part that won't fit. It's is very important to double check yourself. Don't assume someone's bom will cover your build or fit your front panel. It's better to be safe than sorry.

Mouser's site is down for maintenance right now, but you will need 2- Alpha 4-pole 3-position rotary switch for meters. 2- Alpha 2-pole 5-position double deck rotary switch for ratio. 2- Output control pot's 250k audio taper. 2- 25k attack pots. 2- 5m release pots.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Potato Cakes on November 29, 2014, 10:25:12 PM

One thing I think that made the biggest difference with my build was to remove the stereo link boards and replace it with a 600r output termination switch.  I was able to get my 2 channels close enough that the few times I would use link will be fine without the link boards.  The matching was pretty close!  But the added benefit of being able to switch the 600r in and out was huge (both channels on a stereo switch).  That is one a number of you guys may want to try or heck its DIY just add a few holes and have both link and the 600r's on the outputs.

Dan, do you have the model number for the termination switch and the stereo switch you used?

Thanks!

Paul
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: dandeurloo on November 30, 2014, 07:31:59 PM
I just used C&K 7000 series switches like the rest of them in my Stereo 1176 front panel.  The link below has a ton of options.

http://www.mouser.com/CK-Components/Electromechanical/Switches/Toggle-Switches/_/N-5g2j?P=1z0zl2x
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: rdp42089 on March 09, 2015, 10:13:39 PM
Mrerdat,

The diagram is very helpful.  Much appreciated!!!

I followed the wiring diagram but am getting 23.7 volts at R87 on both boards.  Did you by chance get the same voltages?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: weiss on March 14, 2015, 11:39:40 PM
On the collectivecases one the GR bypass is in the meter, so you need 3 positions in the meter switch and 5 positions (4,8,12,20,ALL) in the ratio one.
On the other case the GR bypass is actually in the ratio board (marked as position 1) so you are going to need a 3 pole 6 positions for the ratio and a 2 pole 2 positions for the meter
Okay I understand the visual differences on the Face Plate of the Two and how they would require different position amounts and where the change in positions between the two is due to bypass being on the ratio or meter switch - but is that not determined by the PCB / wiring rather? you say 3 Pole 6 positions but the board only fits 2 pole and 4 pole? - Is there a different way of wiring for different position amounts?

(4-pole - 2 pos (Meter) / 2pole- 6 pos. (Ratio) - [DIY Racked labeling])
(4 pol - 3 pos. (Meter) / 2pole - 5 pos (Ratio) - [Collective Cases labeling])

The latest and previous BOM on mnats page only calls for a 2 and 4 Pole Lorlin rotary switch - no positions mentioned
The original rev D BOM calls for a 4 Pole 3 Position / 2 Pole 6 Position - defined but ambiguous to the case labels.

Hello,
Can anyone explain this? I am building two 1176 Rev A as stereo unit. Seems like there are two different types of wiring.
My personal approach would include following settings for each channel: ratio switch with slam mode, attack switch without bypass mode (gr off), gr/vu switch (without bypass) and a separate bypass for each channel. do you guys think this will work?
or is it only possible to include the bypass mode on either the attack potentiometer or the meter switch? would i be needing a relay for a single bypass on each channel?

thanks for your answers!
weiss

PS: thank you mrerdat for the wiring diagram! ;)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Potato Cakes on October 09, 2015, 04:53:16 PM
Hello, everyone!

I just finished my stereo 1176. I had high hopes of keeping the wiring all sexy and neat, but after having to correct a number of mistakes, I kinda gave up on that goal and just focused on finishing it. I used Volker's HWBP boards for the bypass switch. The Stereo link boards are mounted under the main PCB's. For powering the meter LEDs, I tapped off R89 on the side facing the signal line amp section, which I found to be about 4.5V, which is perfect for these meter lights. One of the +30V test points were used to send power to the by pass boards with a 5W 100 ohm resistor in line at the switch, which put it just under 12V under the load of the relays, which is perfect for them. I swapped the Alpha output pot for a Bourns. The only I noticed is that in stereo link mode the VU tracking seems to be a bit off, and I saw somewhere Dan managed to correct this, but I didn't quite understand his methodology. Perhaps I'll reread it when there is time.

Hopefully I'll get to use this coming week.

Paul
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Potato Cakes on October 09, 2015, 04:53:47 PM
The Stereo link board hiding.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Potato Cakes on October 09, 2015, 04:55:33 PM
The bypass boards.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Potato Cakes on October 09, 2015, 04:57:16 PM
And the top.

Thinking about it now I might have laid it out a little differently, but for some reason I was obsessed with keeping everything away from the power transformer.

It still works great. Throw the top on it and never think about it again....
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Nyquist on June 20, 2016, 02:33:57 AM
Hey DIYer's. Well my dual 1176LN  is up and running. All went well with the build apart from mixing 2 resistors up grrrr.
 
Pics  :D
(https://s20.postimg.org/urkv75so9/11761.jpg) (https://postimg.org/image/urkv75so9/)
(https://s20.postimg.org/pvh8fgsix/11763.jpg) (https://postimg.org/image/pvh8fgsix/)
(https://s20.postimg.org/sbj1tball/11762.jpg) (https://postimg.org/image/sbj1tball/)

I also added the slo .022uf cap attack mod to the attack pot. It seemed not to really do much. Searching around the net I found a post on gearslutz relating to a "slo" mod. The poster used a 220k resistor rather than a capacitor to alter the attack time. post is here
mod.htmlhttps://www.gearslutz.com/board/geekslutz-forum/946616-1176-slow-attack-mod.html (https://www.gearslutz.com/board/geekslutz-forum/946616-1176-slow-attack-mod.html)

Circuit mod from gearslutzs
(https://www.gearslutz.com/board/attachments/geekslutz-forum/411134d1407396063-1176-slow-attack-mod-1176-slow-schematic.jpg)

Can anyone shed any light as to which slo mod is correct?

Cheers!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: midwayfair on June 20, 2016, 10:54:40 AM
Can anyone shed any light as to which slo mod is correct?

This should probably be its own thread since it doesn't have anything to do with the stereo link, but here goes:

The second is, I assume, similar to the way it's done on one of the newer UA versions (based on the way someone described that version to me on Reddit). The 220K resistor puts the attack up to probably about 7ms, and then turning the pot gives you another 1mS or so to play with, giving the sense that the pot is disabled.

The one on the right ... I'm not really sure what that's supposed to do even though I've seen it elsewhere. That capacitor forms a high pass filter with the attack pot's taper resistor; when the pot is at full (longest release) that cap is shorted and does nothing. There's another capacitor that you could change out that goes from the intersection of the attack and decay pots to ground (it's to the left of the schematic cutout). It would also affect the decay so you might not want to change that. [nb I had a thread not too long ago where I was asking about the attack though and I couldn't get the official numbers to work out on the time constants given the value of the attack pot and that capacitor.]

I ended up just using a 250KA attack pot in my build. Except for some change in taper, the original's settings are in the first half of the pot and the longer settings are in the second half.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Nyquist on June 21, 2016, 02:47:33 AM
Thanks a heap Midwayfair. I'm going to give the mod a crack as per the schematic and report back.

cheers!
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Nyquist on June 21, 2016, 09:56:14 PM
So I tried the slo mod as per the schematic in my previous post. Just to confirm it does work and works well. As I have a dual 1176 rotary version the attack pot bypass switch is not utilised. I wired the 220K resistor in using the attack pot switch and I now have a slo mode which behaves much the same as the 1176AE version. I calculated the slo attack mode to be approx 8 milliseconds.

Increasing the value of the resistor would increase the attack times.
Or option 2 for a longer variable attack time you could use a 250K pot maybe something like this would work well http://au.mouser.com/ProductDetail/Alpha-Taiwan/RV24AF-10-15R1-B250K-3/?qs=sGAEpiMZZMtC25l1F4XBUzpDXwZPOA8qZj6wk6EWIf4%3d (http://au.mouser.com/ProductDetail/Alpha-Taiwan/RV24AF-10-15R1-B250K-3/?qs=sGAEpiMZZMtC25l1F4XBUzpDXwZPOA8qZj6wk6EWIf4%3d)

 :)
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Mikolaj on January 10, 2018, 12:10:55 PM
What does the bypass/compressor switch do on the collective cases face plate?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 06, 2019, 05:12:06 PM
Just got around to altering the onset of compression by adding the 1 M trimmers on the ratio boards. Only took me 5 years to get to. I happen to stumble upon this page http://mnats.net/rotary_switch_pcb_ropt1.html and it reminded me of the early onset of compression on my compressor. I added the 1 M trimmer. It reduced the gain quite a bit on the output as well.  Just carefully cut trace with razor blade. This will allow for a bit warmer sound as well because you can drive the input transformer a bit more.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on October 07, 2019, 02:42:12 PM
Also swapped out the 3.6k resistor for a trimmer on the meter board to get better meter accuracy on the +4 setting. Everything works great now.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: TimKoza on January 09, 2020, 08:13:13 PM
Hello,

Pulling my hair out... Looking through all the posts but not finding what I'm looking for.

Wiring a stereo 1176 with rotary switches for the ratio and meter select. Using Lorlin rotary switches. Seems everything is working but how do you wire the Lorlin switches for the SLAM / Nuke position? See diagrams for the Alpha open frame switches but nothing about Lorlin.

Any help would be great.

Thanks!

Tim.

Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on January 17, 2020, 01:16:28 AM
This may help make a link with alligator clips and test.
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on January 17, 2020, 01:30:38 AM
Hello,

Pulling my hair out... Looking through all the posts but not finding what I'm looking for.

Wiring a stereo 1176 with rotary switches for the ratio and meter select. Using Lorlin rotary switches. Seems everything is working but how do you wire the Lorlin switches for the SLAM / Nuke position? See diagrams for the Alpha open frame switches but nothing about Lorlin.

Any help would be great.

Thanks!

Tim.

Do you have a 2pole 5 way switch in there?
Title: Re: Stereo 1176 support - Mnats/Hairball
Post by: Bobby Baird on January 17, 2020, 01:33:12 AM
If you swap for alpha which are cheap to get. You should get the 2 pole 6 way so you can add the 2:1 mod.