Stereo 1176 support - Mnats/Hairball

[tonycamp]

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!

 

[tonycamp]

back view

 

[DaveHilltop]

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

 

[100WChris]

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

 

[DaveHilltop]

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

 

[100WChris]

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

 

[mrerdat]

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)



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.

 

[DaveHilltop]

Mrerdat,
  Thanks very much for the diagram !  It's a nice reference and a great help . Regards, Dave

 

[Axelerator]

..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

 

[eparg]

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!

 

[tonycamp]

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 ;D

 

[mrerdat]

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:



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.

 

[mltamisin]

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?

 

[mrerdat]

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.

 

[mrerdat]

BTW if anyone is wondering, the knobs I used for my build were part number 5164-1510AH 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 

 

[eparg]

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:



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!

 

[tonycamp]

BTW if anyone is wondering, the knobs I used for my build were part number 5164-1510AH 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 

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

 

[mrerdat]

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! 

 

[eparg]

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?

 

[dandeurloo]

There was another member doing true bypass boards with a built in psu.  That is what I put in mine.