I am currently using the HM-2 Cult pcb for a chainsaw build but using the Buff n Blend circuit to help make it more controllable in the live setting. Everything seems to work well and the pedal sounds great with exception of a high pitched hum that becomes audible when the HM-2 is dimed (as god intended it) regardless if the circuit is engaged or not. When the circuit is engaged the hum gets louder. I’ve compared it to other chainsaw pedals I have and none of them exhibit the same hum. Allegedly this circuit is supposed to be a 1:1 of the original Japanese HM-2 so maybe it’s a unique issue to that circuit but hearing the hum when the pedal should be in bypass leads me to believe my error exists on the Buff n Blend.
I’ve re-flowed most, if not all of the joints on both boards to no avail. any and all help would be greatly appreciated.