whine

[vvv]

In some of my builds I sometimes get distant whine when used with a 9v supply. Sometimes it disappears by replugging the DC plug. In some builds it whines with some power supplys ja not with others. Wiggling the wires inside pedal makes no difference. Could that be because I put DC jack next to input jack in my builds? Would it be better to have the DC jack in other side of the box (top)? Or is it just because of bad and cheap components? Or a grounding problem?

[Nocentelli]

Or a grounding problem?

Possibly, or more likely not enough power filtering and a poorly filtered 9v DC adaptor. Ideally, one should use +9v -> 100r series resistor -> 100u electro cap to ground -> power to board. If that doesn't solve it, the problem has another cause.

[vvv]

Or a grounding problem?

Possibly, or more likely not enough power filtering and a poorly filtered 9v DC adaptor. Ideally, one should use +9v -> 100r series resistor -> 100u electro cap to ground -> power to board. If that doesn't solve it, the problem has another cause.

Could that be even a tiny separate box with dc in&out and that resistor + cap inside so you could easily test out different pedals and see if they get silent? Or even leave it on pedalboard to silent all whining pedals?