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

That's not a personal attack. That's a summary.

In your eyes.

Hello georgehifi,

     I can not only handle the truth, I respect it and have a habit of speaking it. Can you claim the same?
     It is true that you did post about the newer GaN technology a while ago and their potential beneficial potential for audio amps and I found it very interesting and promising.  Thank you.
     I have no issues with you touting the potential benefits of faster switching GaN transistors that would result in reduced dead-time and reduced distortion.  GaN transistor technology is a few years old and their potential for improved solid-state audio amp performance are well understood and mainly agreed upon.
      My main issue with you concerns your claim/theory that current class D carrier frequencies are too low and result in sonic shortcomings in the audible range. Unlike GaN technology, the potential benefits of higher switching frequencies for improved class D amp performance have not been researched and, therefore, are not well understood or agreed upon.  The truth is that It also has never been proven that current level switching frequencies are too low and result in any sonic shortcomings in the audible range.
     Yet, you seem to believe it's just a matter of opinion as to whether these sonic shortcomings exist in the audible range. I believe this has yet to be decided empirically.
      My take on this issue is a bit involved but not really complex.
      My reasoning is that,if your theory of sonic shortcomings in the audible range are someday proven to be  false, then that nicely explains why I and many other users of good class D amps have failed to hear them since they don't exist.
       If your theory of sonic shortcomings in the audible range are someday proven to be true, however, then that would verify their existence but present a whole new issue of why I and many other users of good class D amps are unable to discern these now proven sonic shortcomings. 
      I.can state with absolute certainty that I cannot discern any sonic shortcomings on any of my 3 good quality class D amps that all have switching frequencies in the 600 KHz range. 
     If your theory is someday proven to be true and sonic shortcomings actually do exist in the audible range due to the switchng frequency being too low, I'd be very concerned about why I wasn't able to discern these now proven sonic shortcomings.
     I'm now 60 and have never considered myself  to be a 'golden ears',  But I believe I still have good hearing, I'm able to discern the differences between various power cords and interconnect cables I've compared on my class D amps and think I'd be able to hear any sonic shortcomings on my system if they existed.
     After I initially read of your theory concerning the switching frequencies on class D amps being too low and being audible, I was a bit alarmed because I could not hear any sonic anomalies on my class D system.  So, I spent most of a Saturday listening to my system trying to detect any sonic shortcomings in the midrange and treble but failed to identify even a hint of any sonic anomalies.
     Ultimately, I had no choice but to conclude that no sonic shortcomings existed on my class D system.  The only other possible conclusion is that I, for some unknown reason, am incapable of perceiving these sonic shortcomings.  But I consider this a bit of stretch with the current lack of research supporting this premise.
       
    So, I'm going with the conclusion that these supposed class D sonic shortcomings don't actually exist until proven otherwise.  

 Tim

I threw my hat into the ring here quite a few pages back suggesting initially that the Anthem M1 be considered for audition as my personal experience is that I like far better than my very well received Parasound A51 Halo, which of course is Class A/AB depending on the output level.

However as with so many other forums online in various other areas of interest, they often degrade into nasty commentary.  I blame the lack of face to face interaction as I don't believe people would speak this way to someone's face in person (there is too much risk of getting punched).

Anyway, I keep it simple, I stop following any threads I don't find are productive any longer and I guess its time to do just that.

+1 Tim.


George has trouble making the case that a particular technical issue (i.e. dead time) results in a particular sonic aberration common to many Class D amplifiers.


As I may have mentioned, I’ve had a number of audiophiles in my home (when it was better acoustically than now) and no one said "wow, that’s a Class D amp!"


They may not have liked the sound stage, since I make pretty laid back speakers, but not a single person has ever stopped and gone "Woah, that dead time man, how can you stand it?" In my bedroom I use an NAD 3020 D and it is pretty fine sounding. No switching artifacts can be discerned. If you only believe in reviews, fine, go read them and tell me which published reviewer says they can tell its class D.


In fact, once at the end of watching a movie did of watching a movie did my invitees say "by the way, where are your amps?" All my fronts were Class D with a Parasound driving the Surrounds. The sound was seamless. No one heard a difference in noise, distortion or coloration. Room EQ was applied to the sub and center only.


From a practical experience, and listening with others, I am fairly confident of my experience. Class D is dandy. I also have no particular reason to push Class D to those who like tubes, mega Class A or SETs. Enjoy what you want to listen to, with friends and enjoy it. What I have problems with are heroic efforts being made to make people doubt their own experience with Class D. Damn, I wish I could afford a pair of CJ Premiere 12s, because those beat everything ever.


Like Tim, I look forward to new technology. Since I consider Class D being capable of exceptional performance when matched well, I can only hope modern tech makes it even better. But 300 links to discussions about distortion profiles in the 100kHz range are not going to convince me something is wrong with my hearing.

Best,


E

Fellows, this has been a very interesting thread and I even understand a lot of it, but I am reminded of two things:
1) Two ( or more ) cooks can start out to make the same meal and come up with very different products.  It doesn't mean that their food source was bad, but that they cook differently. Of course, if you start out with bad food, then it is harder to achieve a good meal.  Some cooks can do it, while others can not.
2) As more cooks become aware of a new food source, some one will improve on the way that source is used.  In the electronics word, this improvement can happen rapidly.  I hope no one makes fun of this analogy, as I think it is a good one, but improvement in the new Class D technology seems to be coming  fast.
FYI look at the latest issue of THE ABSOLUTE SOUND's cover story on the new and cheap NAD C328 Hybrid.  I predict that two years from now, most new under $1K amps will be Class D and many under $3K amps, as well.