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MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by CGMix on January 26, 2026, 04:50:50 PM »

So in that photo I have a vocal running through and if you look at the knobs, all of them are down. But the signal is still getting slammed. I can faintly hear the source even with the output down. The signal is distorted as well. But again, this is not a constant issue. Sometimes it slams the signal, and sometimes it operates normally.

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MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by JPK on January 26, 2026, 09:40:55 AM »

I am not sure I understand well.
Do you have a sudden excess of input gain? Does it looks like a bad contact? How does it ends? Please explain more.

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CP5176 FET compressor / Re: No sound CP5176

« Last post by JPK on January 26, 2026, 09:32:16 AM »

That looks very much like your issue.
One of the phase is not connected.
It can also explain the low levels.

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MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by CGMix on January 24, 2026, 11:19:45 PM »

Here is a shot

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MU524 Vari-Mu Tube Compressor / Re: Initial AC voltage jump

« Last post by CGMix on January 24, 2026, 07:08:51 PM »

I wanted to jump back on this thread real quick and ask about another jump. This same unit will jump up in input after using it for several minutes. The meter will peg right and distort. So when it does this I can turn the input and output all the way down and still faintly hear it. But then last night I used it for a couple of hours and it never had an issue. 🤷🏼 I swapped slots on the rack to double check as well

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CP5176 FET compressor / Re: No sound CP5176

« Last post by Stam on January 24, 2026, 11:13:15 AM »

Hi again!

Maybe I have found the problem.

When I connect the compressor direct from an electronically balanced micpre XLR output and out from the compressor with an XLR to the soundcard the bass response seems okey. When I connect it through my patchbays backside in normalled mode (which should be balanced) the bass is lacking again. It looks like the problem is in the patchbay.

The compressor is probebly okey now. I’ll get back to you if I suspect that there is a problem that actually has to do with the compressor.

Thank you for your patience and support!
Mats

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CP5176 FET compressor / Re: No sound CP5176

« Last post by JPK on January 23, 2026, 05:10:16 PM »

I am running short of ideas. 
Do you want to send it to us for a check? Contact me at jpk@soundskulptor.com

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CP5176 FET compressor / Re: No sound CP5176

« Last post by Stam on January 23, 2026, 10:18:29 AM »

If I have the compressor vertical as it should sit in the 500 rack the input transformer got it´s marking upwards.
The relay got the line downwards. The resistance goes from 0 to 1.785K on TP1 when turning the P1 pot from min to max.

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CP5176 FET compressor / Re: No sound CP5176

« Last post by JPK on January 23, 2026, 09:47:41 AM »

The values are correct.
Check that the input transformer is inserted the right way around, with the markings facing upwards.
Check that the relay is inserted the right way around, with the white line down.
Check that the resistance between TP1 and ground goes from 0 to 1k6 when turning P1.

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CP5176 FET compressor / Re: No sound CP5176

« Last post by Stam on January 22, 2026, 08:14:27 PM »

Ok, I see ...


Between edge connector fingers 8 & 10 I get 2.16 Kohm