It’s the grounding, there is a cable from the pcb that goes to one of the screws on the bottom. You must screw it (so you don’t need a soldering iron). Mine is dead silent. It’s great.

Is the ps working? is it the right one?

Both are filters, but the flanger has way more notches. Phaser it’s more dramatic, so, I prefer it to make something rythmical, and I prefer flanging for more subtle things, arpegiated, and the flanger must be subtle, wide, slow, not very resonant (or feedbacked) and sound natural, not metallic.

if you need that, use the signal pad. it’s a volume attenuator

There are different tubes for diferent applications, in this case, they’re preamp tubes I think.

the filter creates mid frequencies based on the high and low eq settings

if it doesn’t feedbacks, and it doesn’t alter the overall tone, it’s fine to light up. If it’s permanently on (even when not playing/with guitar vol at 0) then back up on the feedback knob, and if it doesn’t work, then it has something wrong.

any schematic with offboard wiring and the dem’s schematics