Hello,
I have an issue with my CP4500. It worked perfectly after assembling it myself and I've used it successfully for a couple of months. Then after a recording session on location I re-connected the CP4500 to my audio interface (antelope orion studio), but I made a mistake by connecting the outputs of the CP4500 to outputs of my interface and inputs to inputs (all line level). That seemed to have triggered some kind of loop, (I remember a loud noise) so I assume it got quite a hot signal into the circuit. I cannot remember exactly what happened, because it was a combination of hardware and software routing that got messed up.
In any case, the 2nd channel has a much lower output now. I did some measurements and the results below are the steps that are different from what is expected. Channel 1 is working without issues, but I assume something is damaged on channel 2. Could you help out?
Step 2.3 // 3VAC input on channel 2, threshold +15, make-up gain 0:
TP6 = 322 mV
TP7 = 380 mV
TP8 = 322 mV
TP9 = 13.2 mV
VDC pin 1 U16 = 0V
Step 2.4 // 3VAC input on channel 2, threshold -15, make-up gain 20:
TP6 = 322 mV
TP7 = 105 mV
TP8 = 322 mV
TP9 = 39.7 mV
VDC pin 1 U16 = 67.4 mV
all the best,
Arjan