[b.riesel]

Hi guys
I´m on my way to finish my first DIY CP 5176. I solders everything and starts the setup-process.
unfortunately, here something seems to be wrong.

I followed the setup process and at step 8, when I tried to adjust P5 nothing happens. So I started the checklist "In case your CP5176 doesn't work as expected"

At Step 2, I got 580mV DC on the Top Pin of L1 of the SK25. As far as I understand your Checklist, this seems to be to much.
The other Checkpoints are as they should. Maybe point D has a slightly bigger tolerance (-0,16 DCV instead of - 0,2 DCV).

Step 3 brings the following values:

TP1 = 0,07 V AC
TP2 = 0,34 V AC
L1 Top = 1,85 V AC

Step 4
The ratio-values are very closed to the ones, you describe.
TP6 values reach from -1,4 to - 5,4 VDC
TP5 value is 0

Can you give me an idea, what to do now?
thank you for your help!

[b.riesel]

now I did further attempts to setup the compressor.
now I could finish all the steps of the setup guide.
but there's one thing, which seems to be wrong.
With very little input and output gain, I immediately get a feedback in the signal.

I tried to reduce the volume in the FET bias setup with P6, but there also, the signal resonates very soon.
d you have some help for me?
thanks in advance

best regards
stefan

p.s. and is it really necessary, to connect the module with the first slot in the lunchbox and all the other modules disconnected?

[JPK]

At Step 2, I got 580mV DC on the Top Pin of L1 of the SK25
There is definitely an issue here. Probably in the DOA. With no input signal the DC volts should be lower.
Have you got another DOA to try in this position?

TP1 = 0,07 V AC
With P1 at max, TP1 should be just a little lower than your input voltage.

With very little input and output gain, I immediately get a feedback in the signal.
This is not very likely. Are you sure you don't make the feedback loop outside?

[b.riesel]

Hi Jean-Pierre
thank you so much for your replay.
I´m now back in my studio and checked the feedback-thing.
I don't know, what it was. Today it's gone.
I calibrated everything for a second time and checked it out with some musical signals.
Everything seems to be fine now and behaves as it should. Further more, the compressor sounds fantastic!

So what do you think? Should I replace the DOA?
Or should I care about the input voltage at TP1?

Today I ordered a some more stuff and also a separate DOA. So I could use it for the CP5176.
Best regards and thank you so much for this fantastic peace of gear and also this wonderful experience, building it. 
Stefan

[JPK]

So what do you think? Should I replace the DOA?
The easiest thing to do would be to try another DOA. If the issue remains then search in the circuit. If it's gone, search in the DOA.

Or should I care about the input voltage at TP1?
At least you should measure again:
With 1VAC at the input you should get 0.65VAC on TP1.