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
