It sounds like you have a ground loop. This is usually caused by different devices using different grounding schemes.

In the USA some amps allow you to "Lift The Ground".

By plugging it in further and further away you're weaking the ground conflict (not a good solution).

You might be able add a device that isolates the ground.

Some people force the conflicting component to be ungrounded (by disconnecting it) which is not always the safest thing to do.

This is often why consumer devices elect to have no ground and build them "double insulated".

I don't know what the powersupply upgrade involved but if it added a ground that may point to the issue.

Just like an "argument" it takes TWO to disagree smile

Was the factory power supply universal (i.e. could it handle 220v?) Was it grounded? By the looks of images some look grounded and others do not and looks like it was universal. Personally I would have stuck with the factory power supply assuming it would work for you.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
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