Polysix Filter Problem

[pdub]

Hi

I have been having a problem with my Modypoly setup.

When I bring the filter cutoff down I hear what sounds like fast triangle modulation even with no modulation active.

I have set all CC controllers to zero and the Modypoly Triangle speed and depth has no control of the modulation. It also isn't related to the speed of the arp or internal MG.

I have reset the unit, re-flashed the firmware but nothing has helped.

Any help would be greatly appreciated.

Thanks!

[pdub]

So when I disconnect the orange CV option cable from R51 the problem goes away.

Any ideas why this would be happening?

Thanks

[tubbutec]

Hi there,

some Polysix seem to have this issue, most do not. It comes from improper filtering of the filter CV signal in the Polysix circuitry, maybe there are differences between various Polysix versions.

There is a simple fix to this though:

add a 1k resistor in series to the orange filter wire. And a 100nF cap to ground like so:

[pdub]

Thank you!

[bujbot1]

Sorry to revive an old thread but I was pulling my hair out trying to figure out why my filter sounded terrible after the ModyPoly install.

I should have come to muffwiggler. Thanks tubbutec for posting the solution to my issue and for making the ModyPoly!

[tubbutec]

Thank you very much for the report. We will now put this in the installation manual and add the components to the kits.