Hum from new Jolida 502B-Help

used a cheater plug-no more hum !!

I'm looking into the Humbuster, thanks for that tidbit. The amp is stovk, Jolida will provide pre-outs for a nominal fee. Hum is from both speakers, also the powered sub has it. Never noticed this till I installed the Jolida. Will the Humbuster help with a ground loop issue as you described?
Thanks Guys

Is yours a stock unit? I didn't think the 502b had pre-outs. Does the hum come from both speakers or just one side?

In another thread I explained how my small hum problem with my 302B when I moved the system upstairs was completely solved by the PS Audio Humbuster.

You likely have a DC voltage (aka ground loop) in your AC line that is making the 502's power transformer hum.