I own an MC4 (2*500 + 2*250) and I love it! It stays powered up all the time and is always ready to play. It uses only a little bit of electricity at idle and puts out a lot when needed. Aside from all the practical reasons to own one the sound is excellent. I have compared it to a Spectral DMA-180 in my system and the Spectral was only a touch more detailed, just a touch. I beleive all the W4S amps use the ICE modules, and now all have the same input buffer. The input impedance of 64K is adequate for either passive or active preamps. Break-in is the usual 100 hours or so.
