GaN FET Amps vs. Traditional Class D Amps


I'm trying to get a better understanding of GaN FET amplifier technology. Whenever I see a write up on GaN FET based amplifiers they are always compared against class A or class A/B amps. What I'm more interested in is how they compare to the current generation of 'traditional' class D designed amplifiers, both technically and sonically. Can anyone explain it to me?

 

Thank you.

mcraghead

You guys may be right but I remain scarred by my dive into Bruno Putzeys’ NC1200 amps that replaced a pair of pretty good sounding Class A monos and which, at the end of the day, simply didn’t sound real to me.  All of the most satisfying (long-term) amplifiers I have owned were big Class AB amps. 

The OP said:

“Whenever I see a write up on GaN FET based amplifiers they are always compared against class A or class A/B amps.”

I suspect that is a marketing thing as they desperately want to say, “these amps sound as good or better than Class A!”

Regarding GanFET, it seems the concept received more publicity before the amplifiers actually began production and they are now sort of, just another Class D amp. Maybe I need to look harder but based on the reviews I have seen and user posts, my impression is that they are good, to maybe better than good (in the right set-up), but not necessarily as great as the pre-release hype would have had us believe.  However, I admittedly haven’t had a set in my system, partially because I need more than 100 wpc.

There is probably some truth to your comments about better power supplies, as shown by the Theta Digital Prometheus, Class D (Putzeys’ NC1200 modules) monoblocks designed by David Reich with a big-ass linear power supply (review link) .Larry Greenhill raved over them in Stereophile and John Atkinson said,

“The measured performance of Theta Digital’s Prometheus is superb, even for an amplifiers with a class-D output stage.”

 

@mitch2 

I suspect that is a marketing thing as they desperately want to say, “these amps sound as good or better than Class A!”

I think its worth it to compare if you can! I ran class A triode OTLs which my class D amps replaced and I've not looked back. So not just class A, but triode as well...

@atmasphere - If I could get by with 100 wpc, I would give them a try but with my speakers at 86dB sensitivity and 4 ohms nominal - 3 ohms min, it just wouldn’t work.  The 400wpc NC1200s drove them fine and while those amps were quiet, warm’ish, had pretty good tone, and were solid in the lower frequencies, they also sounded overdamped, homogenized in the upper frequencies, and overall a bit dry. They just didn’t display the level of expression or allow the emotional engagement that I heard from my Clayton M300s, Lamm M1.2s, or my current SMc Audio monos, or even from the Cary CAD-500MB monos I currently use for my outdoor system.

@mitch2 Our class Ds clip at 250 Watts into 4 Ohms FWIW. We rate them at 200 Watts. 

Post removed