Question… and you may need to point me somewhere better to ask
i have a schalltechnik Vong Filterung pedal I built sounds great, utterly silent in use
i have a sushi box London Underground and a similar diy valve pedal, 200v plate voltage - sounds great and both pretty silent in use.
put them together, in any order and there’s a high pitched whine. Separate power units and still happens.
what’s going on and how can I bug fix?
if I stick another preamp buffer between I can partially, but not totally filter it out.
I thought I was impedance but it happens either way around.