I’ll first say I have not heard them. But when considering new amps a few years ago I spoke on the phone with this guy. I thought it was a bit strange. A bit aggressive. What turned me off more was the "fanboy" type of customer base, as if these were the be-all end-all of amps, no other amp could touch these and you’ll never need another amp. Check out his forum page on that small-builder audio site. Ended up looking and buying elsewhere.
