they syncing i meant is just to make sure, that your main oscillator starts at zero when the envelope opens the vca (or pitch envelope, for kicks usually necessary). but if you donāt even used envelopes then you just have a free running oscillator with fm from a square wave oscillator right? and that results in clicks? if so then i donāt know the answer to the problem, clicks shouldnāt occur this way. maybe itās the polarity of the modulation signal, the lfo is bipolar? the cv2 input wants unipolar signals i thinkā¦not sure, and not sure what happens if you feed it bipolar signals. so try to offset the lfo signal so it is above zero and then feed it into cv2, maybe that helps?