Okay played around with my VCAs a little bit more and found the Doepfer 130-2 VCAs are creating a pretty loud clicking sound when being on volume control duty. Out of plaits is connected to the VCA and CV is connected to an LFO (doesnt matter which waveform). Is that normal or am I doing something wrong ?
-- 9xpad
If the issue isn't limited to one waveform (and one that has a hard leading edge!), then my bet is that you could be overloading one of the inputs...and since it's a "click" on the output, my bet is that the culprit is the CV input. Try this: set up a VERY SLOW triangle LFO, then feed that to the CVs. At the same time, also connect an oscilloscope to watch the LFO cycling through the waveform. My bet is that once the LFO reaches the maximum voltage limits, the "click" appears. Also, set the scope so that you can read the voltage on the Y axis, and you'll have a good indication of what's really happening and at what voltage level it occurs.
This click could also be the result of some DC offset voltage getting into the LFO waveform and pushing it well beyond the operational limit of the CV inputs. Remember: if you have a +5/-5 volt cycle, inputting an offset will make that +whatever voltage the offset is. Jam in an offset of +10VDC, and suddenly your high value on the mod signal is peaking at a really unacceptable +15V. If the LFO has an offset control, that should be at ZERO when generating bipolar modulation signals.