[BUILD] 1176LN Rev D DIY

[dustbro]

Could this mean Q14 is faulty or more likely something downstream from Q14-E? I wish I knew enough about transistors to work it out.

They are quite easy to blow up. I'd swap it out and see what happens.

 

[Hyder]

Thanks, that's what I thought.

Hello, First time poster so I hope I am doing this correct. I am Building a REV D and the BOM calls for a .022/100/5 Wima film cap located on the attack pot (C27).
Well Mouser sent me a.022/250/10 Wima Polypropylene Film Cap instead.
Is this a problem? All the pics. I see it looks like a ceramic cap or something.
Thanks,
Chuck

No problem.
Capacitance is the same. Yours has a higher voltage rating and 10% margin instead of 5%.

 

[Mixmaster-Nate]

Hi Everyone,

I've just finished my Mnats Rev D and plugged it in.

Everything is working fine, and the unit operates normally & sounds great compared to a genuine 1176D I have, except two points.

During Gain Reduction/Meter tracking stage of the calibration process (video 3), I encountered an issue;

1. I zeroed the R71, no signal, meter in GR. All good.

2. Meter back to VU, input & output knobs at 50%
- attack to 'Off'
- feed it 1kHz @ 0.775v
- adjusted output knob so meter reads 0dB
- attack to 'on' and output drops to -7dB
- now here is the issue - if I turn the input knob clockwise it does the opposite of what the video says. I turn it down (instead of up) the VU goes to -10dB as the video describes.  Switching between attack ON/OFF and adjusting the knobs I eventually run out of 'knob' before I achieve the desired result...

The 2nd issue is;
- with the meter on GR mode, when I push 'all' the ratio buttons in, the VU pegs hard right and the only way to get it back is to turn the input knob up more....huh?

It's as if the input circuit has something backwards, yet the input works perfectly when passing audio just like it should - however I can not calibrate as mentioned or use 'all' buttons in mode.

I throw it over a kick drum or vocal however and it sounds and works beautifully just as my genuine 1176 does.

Any thoughts?

Thanks in advance.  ;D

 

[ilfungo]

is normal with all the buttons in the meter does so
the compressor goes in unexpected ways ....
No problem

 

[Alistair]

From memory the video is worded in a way you can interpret backwards.
It's been a little while since I calibrated mine, but I remember thinking exactly the same thing as you, and thinking something was wrong.  Try and follow the instructions regardless of whether you think you're doing the wrong thing, and just make tiny incremental changes and keep switching back and forth to see the overall effect.
You end up turning the input up, so that when you switch back the output is on +2 instead of zero.  Then you switch flick back and it's on -8.  So you turn it up, so when you switch back it's on +1 now.  So you turn the output down again, and when you flick it back over, it now reads -10.
Does that make sense?  You're actually really adjusting the opposite mode of what you can see with the controls.

 

[canidoit]

Sidechain link using the Hairball/Mnats/PurpleAudio stereo link kit by lifting R205. Needs a second switch to chose from stereo link, sidechain link in addition to a link switch. About to try it and see if it works...
(interesting note: the MC77 does a sidechain link by making balanced send/returns... but by using the buffer on the stereo link board, it should be *ok* to send unbalanced? i.e. noise cannot go backwards into the output pot & audio signal)

Anyone had any success adding an external sidechain to this 1176 build and is there a simple way of adding an external sidechain to the 1176 like a PCB and wiring diagram? I know Hairball has one for stereo linking.

Does anyone have a part number on the pot they used in replacement of the blue trimmer for zero adjustment on the front panel for purusha's case?

I just checked my r12 is 920r as written on the PCB board and noticed the problems people were talking about in regards to how it performed so I would like to replace that.

 

[Ayman59]

Hi all,

I need your lights!!!

I just finished a 1176 rev.D unit during the week-end then I tried to calibrate my unit.
I succefully adjusted the Q Bias and I calibrated the discrete meter circuit...

Now on the third step of this process I'm having troubles to get the 0dB > -10dB > 0dB > -10dB readings...
In fact I can't get the 0 -10dB readings by adjusting input and output pots... I'm facing the wall with the ouput pot fully CW and I have small amount of GR on the VU when I turn on and off the attack pot...

Do you guys have any idea on this problem???

Thank you in advance 

 

[XeNoMoRpH]

Did you disable the gain reduction with grounding pad 22?

I edited AXT Systems' calibration guide and added some notes that I found useful for calibrating my Rev J. You can find it on my blog here: http://www.xenoworld.org/?page_id=214

I'm not sure if it applies 100% to the Rev D.

 

[Ayman59]

Thx for your response. Very nice blog!!! Wonderfull tutorial... I will try it.

Yes I disabled GR with the attack pot turned fully CCW (Hairball kit).

I will try to replace the VU VCA... it's like vu meter can't display gain reduction when I'm compressing. The needle stays on 0dB!!!

 

[Ayman59]

I think I will spend a long time searching for the VCA !!!!!!!!  :-\
Dummy post... sorry I still had the SB4000 in mind when I wrote.

 

[college101]

Hey guys--quick question...do the capacitors for C19 and C20 have to be polarized? I ordered some caps, and they are not polarized...wondering if this will cause any problems?  thanks  College101

 

[college101]

Guys..the only reason I am asking is because the schematic shows c19 and c20 as polarized capacitors, and the caps that most people are ordering from mouser, the tant ones, are non-polarized...

 

[TijuanaKez]

Those tant caps are polarized, it's hard to see on the tiny ones but there is a little + above one of the pins.

 

[pietro_moog]

hi guys.
i'm looking for a good heatsink with a clip for the VR, from mouser.
do you have a suggestion?

 

[college101]

Ahh..I was guessing that they were, but info I was finding on the net, was that they were not polarized... I actually just installed some electrolytic caps in place of them...

 

[Majestic12]

Where can I find some information about the wireing of the 1167 Rev G. ? Don't know what to put into the search engine to get usable results.

 

[s2udio]

1167 Rev G. ?

Maybe 1176 G ?

 

[Majestic12]

The only things I find are for the Gyraf version.

Is there a Rev G thread at all?

 

[s2udio]

http://www.groupdiy.com/index.php?topic=646.0
What more do you need ?

 

[uzak33]

i startet to build the 1176 rev D from Hairball with Mnats Rev D Board and all items from Mouser.

Are there pictures from a finished PCB + Ratio Board any where? So i can refer to that.

Many thanks for your help.