Polivoks issue [solved]

Having some trouble with a Polivoks - most everything works OK, except there is no change in response to cutoff/resonance control. I have enabled PVK in settings, saved, and verified on many recycles that it’s on. I have verified good connections between the filter and control board, and have reflowed all joints on the control board for fun! I’ve got approximately 0 - 5V at pins F/Q with changes in cutoff/resonance. Changing from BPF/LPF, overdrive, FM, etc all seem to have zero effect on audio. Would appreciate any pointers - thanks in advance.

Perhaps worth noting that I self sourced (a year ago…) and the only parts I recall not being directly from the BOM was a change to a Newhaven OLED, which seems to be working fine with the pads for the current limiting resistor shorted.

Could you post pictures of both sides of the boards?

Might have found it…

Great what was it?

A missing solder joint somewhere around the connectors of both boards? :slight_smile:

I’m a bit ashamed (on two counts) to admit that I noticed the problem as I was uploading images from Christmas mass…and it was as easy as a missing LT1054. Spent too much damn time looking for bridges/debris/cold joints, and not enough time making sure that I’d populated all the sockets! Shiftr - thanks for the help! Forced me to put fresh eyes on it.