Clayton Amp owners - do you have a hum?

Greetings ... I run Clayton Audio M70 monoblocks and have always been aware of what I assume to be a transformer hum. I recently moved the system to a new dedicated room, and now the monos each have their own dedicated 20 amp circuit, wired with 10-2 w/gr. MC cable, and VD duplexes. Previously, the amps were part of a "makeshift" 2 ch./Ht setup, and I always thought the hum was attributable to less than ideal house ac and equipment positioning. But unfortunately the hum has accompanied them to their new and better environs. The only thing I have tried to this point is to drop their grounds w/ cheater plugs, and I couldn't tell any difference. The hum does not emanate from the speakers, and it's weird to describe, but it is very hard to localize by placing one's ears right up to the amps - it's more of a background presence. It has been suggested that I try a BPT conditioner, but I really can't afford the price of admission at this time, and to be honest, I really thought the dedicated power lines would have eliminated it. I have used Shunyata Black Mambas on the amps from the start- come to think of it, I've never even tried the stock pc's - probably would make sense to do so, for a reference point (duh!) So, just wondering if if any other Clayton owners have experienced the same? Thanks...
I auditioned some of the clayton monos several years ago and experienced the same thing in my system. Never did find out what it was because I did not purchase them. They sounded wondeful otherwise
Sounds like a ground loop hum. Break the ground in one of the amps. If there isn't a switch on the amp for it just replace the power cord with one that doesn't have a grounding prong.
You may have DC offset on your ac lines which is causing your tranformers to hum. Go to and key in dc offset you will get further explanations on this problem, PS Audio has a Humbuster which removes dc on ac lines, Krell Amps have a humbuster circuit in their amps which removes the dc voltage.
Thank you for your replies, gentlemen - I appreciate the input:

Ehoehn - Interesting! I can't help but wonder if the hum is an idiosyncracy of the Clayton design, perhaps in their earlier renditions such as mine. Hopefully some other Clayton owners will respond and either support or refute this idea. I need to contact Mr. Shen at Clayton for his advice.

Jazzdude - suffice it to say I'm still on the steep part of the curve w/ this hobby (affliction :-) but have read enough posts here on the forum to initially conclude that I was dealing with a gound loop problem. As stated, I have lifted the grounds on the amps, but I'm sure I need to do more investigation in this area. As an aside, I also possess the Sim W5, and have heard it paired w/ the Thiels CS 2.3's in a friend's system - very nice indeed. I bet the addition of the Supratek has really placed your system's sound in the "way sweet" category! The W5 currently resides in its shipping box, awaiting duty as the mains workhorse in our HT sytem, once reassembled. I need to get off my duff, and substitute it into the 2 ch room in order to get another take on the AC delivery. However, I wonder if different components can simply respond differently to the power issue - dumb question I'm sure.

Jejell - DC offset, hmm - I've seen the term before but that's about it. I intend to do my homework over at AA - thanks for that suggestion! I have read a bit on the humbuster, but was hoping I wouldn't have to add anything between the wall and the amps. Less is more, as they say ... but maybe not.

Thanks again, guys ... regards, Tom
Tburn - Sorry that I had missed the part about the you lifting the ground already. Did you try it in only one amp at time, though? I mention this because I had Bryston 7B-ST monoblocks in the house for an extended audition once. And I encountered that that ground loop problem. It was fixed by lifting the ground in one of the amps and leaving the other grounded.

Thanks for the compliment on the system. It has a fullness and liquidity unlike any other that I have heard.