Competitive class D amp suggestions

Perhaps what we need is an amp with variable second and third harmonic controls, so that we can dial in the exact mix that we prefer.  

This can be done with digital signal processing, or something similar. I think its a good idea - that is I think what Nelson Pass used on test subjects to reach his optimal tweaking of included harmonics.

I don't know how difficult it would be to realistically implement in an analogue amp intended for home use.. Probably would be expensive - just a wild guess.

@mglik, the Berning Quadrature Z are $33k list. I'm not one of those people that feels the higher the cost the better the sound. While the Berning amps are quite good, and I respect David Berning as an innovative audio engineer, I'd never pay $33k for them. Too much out there at a fraction of the cost that is a better value in my opinion. So yes, the Atma-Sphere Class D were right there with them, so much so that I packed the Berning Quadratures up today to get them ready for sale, to be followed by the Atma-Sphere M-60s. I am keeping the Atma-Sphere Class D, as well as my Music Reference OTL-1, RM-10, and RM-9 SE amps.

I am very sad that Ralph’s Class D is designed only for Nth America and Canada (and perhaps a few others) electricity supply, otherwise I’d be placing my order.

@noske We recently documented that our noise emissions meet EU directives; we always had intention of selling overseas.

The interesting thing from the March Audio review/test is that although the distortion is very low, the remaining distortion is mostly 2nd and 3rd.  The question  becomes "although it has great bass and an extended top end, is it musical"...or is possible that the distortion possibly too low for optimal musicality?

I have just realized that i don't really know which order harmonics  THD measures. My rough  believe now is that if it is high for 2nd and 3rd order harmonics then its fine (i found the article from your latest link particularly useful and well argumented).

I have a suspicion that since Tommy was an admirer of Nelson Pass, he got the 2nd and 3rd harmonics where he wanted them while driving total distortion low.

We will now never know that... I suggest  this can be a best way to deal with the distortions! Such an SS amp could also sound like a tube amp. 

I just recalled the third degree polynomial from the article. Not sure but it might be the case that THD takes a mere weighted sum of gain, the second and third degree harmonics. More refined parameter would measure the distortion of the gain, second and third order harmonics separately.