Experience with Simaudio Moon North amps

I have the SIM audio 861 and comparing it to the 761 everything is just that much better the separation, air and space between the instruments decay of the echo, the voice sounds more human and I think my estimation was wrong now that I've had it for a while I think it's even more than 25% better than the 761, because of the MDCA circuitry this is the only amp that I know of that has no local or global feedback and I believe that this amp will beat amps in the 40 to $60,000 range from any other company It's that good. Lookout Boulder and Gryphon.

Zuesman that is great! Happy you love the 861 so much. I’m also smiling b/c that implies, by your calculations, the 761 beats amps in the 0.75 x 60,000 = 45,000 range ( it’s about 75% as good as the 861). I have never heard a 45k amp, much less had the opportunity to directly compare such amps in my specific system, so I can’t comment, but I can say the 761 is phenomenal across the board and has beautiful synergy with ATC. I also found that the 761 responds well with a DPS 4.1 power cable. Happy tunes!

Since we are talking about the synergy between the preamp and the moon amp, I'll share my experience. I heard the moon audio 761 paired with macintosh's flagship preamp C12000. 

It sounded incredible. It was open, rich, fluid like. It really was a surreal experience. It was so good. I bought the C12000 preamp and I'm gearing up to get the 861. 

So, the Moon 400M's are not in the same ballpark then? A step down perhaps.

I ran the 761 for a month and returned it.  IMHO, it had an upper mid-range frequency emphasis that made it lively but much less warmer than the 760A.  I preferred the 760A sound paired with a Mola Mola preamp. The presence of the 761 makes sound stand out and feel more real or "present" in the mix but definitely colors the overall sound, and not in a good way IMHO.  I'd recommend an old 760A over the 761.