Timchen, The Claytons run at true Class A and have a peek curent of 150amps on the 70's and 200amps on the 100's. My speakers are the ATCSCM50's, in the past I have run many amps on these speakers, amps like Krell KSA-250 and KMA-100 mono bloc's, Accuphase P-360 and P-300, Crown Macro Reference, Bat VK-500 and the Bat VK-60's mono bloc's and a few Adcoms as well as a PS Audio 250. All the above amps did some things right and failed in other areas. My main concern was wanting the slam of the bottom end with the joy of a undistorted mids and highs at high volumes. I was still on the hunt for the right combo when I came across a pair of the Claytons M-70's and did alot of checking up on them before I bought them. As soon as I turned them on and let the music flow, something inside me clicked, I knew I found what I was looking for. The more I played them, the more they did things right. I'm not trying to make this sound like a review for I'm far from being any type of High End Audio Reviwer, but if you can get a demo of these and run them on your ATCSCM20's I feel you will have that part of your music chain complete. Also you may want to note that when one of the many reviews were done on the amps, they did in fact team the amps up with a pair of ATC's. I will try to find the reviews on the amps and send you the links.