Maddening HUMMMM


In an attempt to get rid of a very loud speaker hum from my tube monoblocks, I've done everything I can possilbly think of, including the following;
Changed out Interconnects, the pre amp, and the speaker cables and the speakers. I've pluged each amp into a Lightspeed A/C filter, and then gotten rid of the filter and plugged directly into the wall w/o the filter. I've plugged the amps, via a 10 gauge extension cord into different wall outlets, including one dedicated outlet. Cheater plugs, then no cheater plugs, then different combos of cheater plugs or not. I disconnected the pre and had just the speakers cables to the speakers. I tired a different speaker. I've gotten up at 4 AM and turned off each circuit at the panel, then listened again. I even tried a different amp. I've lifted the cables off the carpeted floor. Using tape and assorted other devices, I've made certain that now power cords are anywhere near the ICs or speaker cables. All Components are on rack with carpet piercing spikes. NOTHING I DO ELIMINATES THE HUM.

This all started about six weeks ago when I rearranged my room and hooked up my system on the other side of the room. No hums before. Now the mega hum. This is no small noise. This is loud enough to hear in the next room. HELP ME, PLEASE, OR PUT ME OUT OF MY MISERY!!!!! Thanks for any advice you might offer. I've tried everything I can think of. Kolledog
kolledog
Also a "ground loop" will cause hum. Buy an inexpensive gounding plug(adapter) and break off the ground terminal. Plug your power purifier into that(it will float the ground), and see if it helps alleviate the problem. Some equipment reverses AC phase from others, and can cause 60 cycle hum(like your TV perhaps). Many pro sound amps have two "on" positions(one reversed phase from the other) for this very reason. I've lost count of the times I've eliminated massive hum by flipping a plug over the years(harder to do now that everything is polarized).
Years ago I sold an amp to a guy. It hummed. It never hummed in my system;ever. Flourescent lamps in his laundry room were the problem.---Got any; anywhere in the house or garage??
Are you getting physical hum from the monoblocks? They may be vibrating a little more since moving or being put on a new surface? Tighten up the transformer screws...
Get some cheater plugs from the local hardware store for about 25 cents each and try lifting the ground on various components until you figure it out. I agree with folks above though it's probably your tv/cable box. Good luck!