Polysex VCA ENV Problem

[Anonymous]

Hi

I just finished installing the Polysex in my already Modypoly equipped P6. Everything works great and sound awesome but the ENV no longer controls the VCA. The Gate / EG switch has no effect and the synth is always in gate mode.

Any ideas what I could have done wrong?

Thanks!

[Anonymous]

When I first powered it up I blew a fuse and realized that pins 4 (-V) and 5 (GND) of IC16 were shorted. I fixed that and replaced the fuses and it powered up fine. I wonder if IC16 is the problem?

EG works as expected on the filter, spread and pitch.

Thanks!

[Anonymous]

The problem has gone away. I’m not sure exactly why but after examining the Polysix schematic and realizing that the VCA ENV signals don’t go to IC16 I probed around the ENV outputs at R218 to check voltages an soon after the VCA started working correctly. I can only think there must be a bad connection at one of the tap points for the ENV to go to the Polysex board. For now it’s working!

The mod is amazing. It really adds another depth to this synth.

Thanks!

[tubbutec]

Happy it is working now, hope the problem does not occur again.

[Anonymous]

Hey!

Well I screwed it back together and it worked for a little while but then it cam back. ENV alawys works for filter and Polysex so it seems it must be something at the VCA / Gate switch or at R218. Would you agree?

Thanks!

[Anonymous]

Ok it’s working again now. I’m pretty sure I figured out the problem. There’s a small via hole under the top of the first R218 and it was being shorted by the extra solder connecting the new ENV line to the Polysex board.

[Author]

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