Archive of the former Yahoo!Groups mailing list: Yamaha CS80

Hi guys,

I have a question about the CSY-1 transplant I am finishing off. I've been meaning to finally put the lid on this for a year or so now... so I've revisited it. I 'extracted' the synth part from an old CSY-1 organ amd made a cabinet for it so what I have here is basically a three and a half octave SY-1.

It's all working great considering what it has been through...!

Apart that is, from one thing. The filter resonance slider doesn't seem to do much. It does affect the sound but only with an apparent slight volume level difference when I move the control. The frequency slider works fine.

My question is - is this most likely to be the potted low pass VFC unit? On the schematic there doesn't seem a lot around there... just some resistors and one cap, a 4.7mfd which I have change, but it made no difference. Are there any parts of the circuit other than the potted assembly, that I could look at regarding lack of resonance..?

Any help/pointers much appreciated.
Cheers,
TOM