Mechanical Hum from Class A Amplifier Clayton

That is a shame, though I can not blame you, I know what a hassle it can become. As I posted earlier, I gave up on my M-100 monoblock amps too for transformer hum. These are great sounding amps when the music was playing, but that constant hum during quiet passages eventually drove me to sell them.

Many folks don't have issues with these amps, so they just seem to be very sensitive towards the electrical lines, which is very unusual for solid state designs. I've had issues like this before with tube equipment, but outside of Clayton Audio, I have never had issues like this from solid state designs.

No matter what I did, the noise and distortion is always present. The fact that the midrange and upper frequency was very distorted during higher spl levels drove me to think something is seriously not right. Both Monos had noise which I find it way above normal use. Yes my Speakers are all sensitive but this is no excuse. a Very well built amp should not make too much noise. This sort of noise was not your average hiss. It was a multiple frequency buzzing noise with background hiss. Something I have never heard. It is a shame as the amps have potential but a loss of just under 3000 dollars in all shipping and agents, Tax, Duty and clearance at 2 ports just really too it too far. I was hoping the second time round they were shipped back to me it will be fixed yet it felt like nothing was changed. Wilson is a nice person, its a shame that my units turned out to be like this. Guess it was not for me and I cant run the risk of taking another chance.

Dragon:
Don't overlook the CODA 15.0 amp. I can't say enough good about it. Tons of juice and NO hum or vibration. You can always get 2 of them and bridge into a dual-mono configuration. That is the amp I use with my Purity Audio Design preamp, and it is superb.

Yes but the coda is only 100 watts into Class A

Yep, and it will knock your socks off. But only if you listen to it. If you are really concerned about wattage, either bridge it in mono (as I had suggested) or try the Model 33.0. Legacy has told you how good they are, I am sure.