Stereo 1176 support - Mnats/Hairball

[dandeurloo]

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

 

[rdp42089]

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?

 

[weiss]

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!

 

[Potato Cakes]

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

 

[Potato Cakes]

The Stereo link board hiding.

 

[Potato Cakes]

The bypass boards.

 

[Potato Cakes]

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....

 

[Nyquist]

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 




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

Circuit mod from gearslutzs

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

Cheers!

 

[midwayfair]

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.

 

[Nyquist]

Thanks a heap Midwayfair. I'm going to give the mod a crack as per the schematic and report back.

cheers!

 

[Nyquist]

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

 

[Mikolaj]

What does the bypass/compressor switch do on the collective cases face plate?

 

[Bobby Baird]

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.

 

[Bobby Baird]

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.

 

[TimKoza]

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.

 

[Bobby Baird]

This may help make a link with alligator clips and test.

 

[Bobby Baird]

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?

 

[Bobby Baird]

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.

 

[JerryPbury]

Anybody doing true bypass boards for 1176’s? Or have a schematic or Gerber files? I am finishing up a Stereo 1176 that I started about 14 years ago using Mnats G1176 boards

Thanks!

Jerry

 

[Clbraddock]

Hi all, this is my first post to groupdiy. Hopefully, this is the right thread to post my question in. If not my apologies.

I am working on a pair of hairball 1176D compressors. I already completed one which is working great on its own. I am building the second one right now. I ordered the 4 matching transistors from hairball (I believe it is Q1 and Q11 on each unit) so those should be matched. Reading some of the threads here, however, now Im worried if I need to match other components. Can anyone provide me a list of components that need to be matched between the units? I will be using them with active link. I realize this thread is more about stereo 1176s in one rack unit, but I figure the component matching would still be the same.

Thanks!!