subwoofer 60Hz buzz

Thank you all for your posts.
I'm certain there's not an interconnect issue, because the buzz is there even when there's no interconnect at all.
It's also not the outlet, for everything else works OK in it and the subwoofer is buzzy in other outlets as well.
I'm leaning towards the power supply filtration capacitors.
Thanks again.

I had a hum from an 8 ft rca run, tried a shorter cable and rerouted away from ac cables. No problems now.

Sounds like a bad IC to me. Try a differant one.

I'm not an electrical expert but could it be the electrical outlet itself? Maybe it's cracked ever so slightly inside or maybe it saw a power surge while you were away on vacation and became slightly damaged. After all, most are low cost contractor grade outlets. Have you ever considered upgrading your electrical wall outlets to for example a PS Audio Power Port? I've upgraded all of mine to these Power Ports where I have my audio and HT systems plugged in. Sound is all crisp and crystal clear. These ports use hospital grade internals and sell for around $50.00 each. Another question: does your sub-woofer interconnect cable have a separate ground wire where you can connect the horseshoe clamp to a screw on the rear of your amp or receiver? I believe you could still get some buzzing even if the input is disconnected. Not 100% sure but could be. I have to subs and both use interconnects with a third ground wire (AQ brand)