Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???

Bel Canto.

singintheblues,

     The use of GaN semiconductors in class D amps, despite georgehifi's repeated claims to the contrary, currently have not been established as providing definitively superior sound quality to the technology and semiconductors employed in the better class D amps available on the market today (typically Field Effect Transistors referred to as FETs).

      As you learn more about how class D amplification actually works, you'll understand why reduced dead-time and higher switching frequencies have the theoretical potential to improve performance. 

      From my understanding, however, it seems that the GaN semiconductors reducing the dead-time has a greater potential of improving sound quality than higher switching frequencies do.  I believe this because faster semiconductors would reduce dead-time which would result in reduced distortion and likely better sound quality.

       The need for higher switching frequencies in class D amps is usually based on the theory that current frequencies are too low and cause sound anomalies in the human audible range of 20- 20,000 Hz.  Current class D switching frequencies are typically in the 400-600 KHz range with theory proponents claiming switching frequencies above about 1.5 MHz are required to ensure there are no sonic anomalies in the audible range.

     However, this theory has never been scientifically proven and there's virtually no evidence to support it.  Several class D amp designers. including the highly respected inventor of Hypex NCore Bruno Putzeys, have publicly stated there's no need for increasing the switching frequencies  above current levels. 

                  
     For some unknown reason, georgehifi has continued to disregard the lack of evidence and has remained one of the very few people still stubbornly clinging to this unsupported theory.  Perhaps, in the spirit of keeping an open mind, it will be discovered that only a select few individuals are capable of hearing these supposed sonic anomalies but that's a bit of a stretch.

     I'm a big fan of class D amps and have replaced all of my previous class AB amps with them.  The class D amps in my combo music and HT system (ClassD Audio and Emerald Physics stereo amps and D-Sonic mono blocks) are smaller, lighter, run cooler, use much less electricity and sound much better than my old amps in all important criteria I care about.  Highly recommended.

     I definitely don't think there's a need to wait for GaN semiconductor technology to 'trickle down'.  As I believe you've already discovered, good class D performs exceptionally well.  If you're not afflicted with hearing sonic anomalies either, why wait?  Perfection can be the enemy of the extremely good.
   
      As far as good class D suggestions for you, I'm willing to offer a few brands/models to consider but would prefer knowing more about your system, needs and budget first.  

Enjoy,
 Tim
     
      
        
 

I listened extensively to the LKV Research Verito-1 and it is an excellent integrated amp based on the Hypex NCore. LKV also offers a stand alone power amp. Check them out!
https://www.facebook.com/LkvResearch/?__tn__=kC-R&eid=ARCfxvDUlp14H2bLZxx5uQVzQ12n9M7a4g4ySnfkhI...

The use of GaN semiconductors in class D amps, currently have not been established as providing definitively superior sound quality to the technology and semiconductors employed in the better class D amps available on the market today (typically Field Effect Transistors referred to as FETs).

The GaN btw is a developed by the same guys that gave us the Power-Fet all those years ago, they sold the rights to it to the world.

Once the GaN of their’s becomes affordable (with mass production), so that Putzy can get them, I guarantee you he will use use them.
If your spend your money now on the present technology you may have an unsellable amp when the GaN technology takes off.

I definitely don’t think there’s a need to wait for GaN semiconductor technology to ’trickle down’. As I believe you’ve already discovered, good class D performs exceptionally well.

But it still does not compete with the best linear amps.

Hypex NCore Bruno Putzeys, have publicly stated there’s no need for increasing the switching frequencies above current levels.

Of course he does because he can't go any higher "yet", and there’s never any mention from him or you (not that that matters) of the output filter (that is the real problem) that has to rid the switching frequency from the audio band and the effects it has on the sound, right down to 3-5khz.

I am waiting for Ralph Karsten to finish his Class D amp. If anyone can build a great amp, it’s him.

He makes great tube OTL’s for a small sector that use speakers they are suited to.
The Class-D is just going to be a money spinner for him, he buys the modules does a small mod so it can be said to be better, throws in in a box, and there’s his beer money.

georgehifi,

     I stated the GaN technology will reduce dead-time and likely result in even better class D sound quality.  I believe this could be a significant step forward even though I have yet to hear an amp using them.  My main point being current good class D amps sound so great, why wait for perfection? 
     Class D amps utilizing current technology will not suddenly become worthless just because possibly even better class D amps are available.  How low current amps would drop in value relative to new GaN amps is likely to be a function of the actual sound quality and price variances between them.
     I do agree with you on the importance of the quality of the filters used in class D amps that removes the carrier switching frequency from the audio signal prior to amplification.  I believe improvements in these filters  probably has more potential to improve the quality of class D than raising the switching frequencies would have.  I was going to edit in some comments into my last post about the filters but realized my omission a bit too late.
       I don't perceive any sonic anomalies at all in any class D amp I own or have ever listened to.  Perhaps I'm just lucky or maybe it's just that no sonic anomalies in the audible range exist.
     I think not buying a current class D amp because the semiconductors are not yet perfected is akin to not buying a 427 Corvette in the 1960s because the fuel injection wasn't yet perfected.  In either case, you're just denying yourself the enjoyment of the extremely good due to a lack of perfection. 
    But experiencing the enjoyment of good class D is currently more important to me.  If I enjoy the sound of new class D amps utilizing GaN semiconductors or a higher switching frequencies more in the future, I'll probably buy a few if the price is reasonable.  I'll offer my current class D amps to both my sons at good prices.
     I'm also eager to see and hear Ralph's upcoming class D amp

Later,
 Tim