I generally agree with Gary here but I don't agree with ungrounding any amp.

Some amps are all metal, non double insulated with high voltage near the cage and are designed to be grounded. It won't blow up ungrounding it. I also agree folks do it all the time. But that does not make it right, or safe. I think it's less probable of something going wrong and potentially hurting someone to lift the ground on the Oppo instead (and loose the "noise dump" feature).And Gary agrees that's an option too.

If it still hums (lifting the Oppo ground) I personally think the issue is with the Oppo, but we won't know that until Mark tries it.

- Fiddler (IMHO)

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