e-licktronic Forum

The snappy pot seems to work fine. The amplitude of the envelope decreases when the pot is turned counterclockwise, which is expected.
The circuit between the white noise source (WN) and the junction of R185-D54 is a VCA. The white noise source is amplified by the envelope.

The waveforms shown in my snapshot do not seem to be correct but I am not sure what the expected waveforms/voltage are and how to trace back the issue.

A good night and I found the issue. Transistor Q48 was dead.

Unfortunately I still have an issue with the decay/envelope of the white noise of the snare drum.
The first part of the decay seems correct but a slight noise remains in the sound for some time.
The waveform measured at R184-R185-C52 point shows some offset or slow decay:


If I add a 1 Mohm resistor in parallel to C52, the issue is resolved.

Do you have an idea about the cause of the issue? Could it be a problem with C52/100nF capacitor?