MXR bass octave deluxe randomness

[LukeFRC]

I picked up a secondhand broken pedal kit off someone, and he chucked in a faulty mxr bass overdrive deluxe for free.

Basically the thing doesn’t seem to be filtering the signal going into the detector- so there’s a constant noise coming out when the bass is plugged in but muted. Roll off the volume on the bass and it goes - so lack of LPF on the signal?

What would cause that?
- trace here https://www.freestompboxes.org/viewtopic.php?t=30057#top

 

[LukeFRC]

So it seems that the it's high end content coming from the bass, that's inaudible until an octaver brings it down into the audible range...

looking at the circuit ... green is a buffer of some kind? - which then goes into the two octave circuits and the envelope follower/frequency divider bit.


The odd thing is if I touch the circuit with an Allen key (so ground it via me?) at either of the yellow spots the noise goes. Caps don't show as open.

 

[LukeFRC]

sorry to ask here, it's not a pedalpPCB pcb but the combined knowledge of this forum might help!