Class D is just Dandy!

GaN transisitors don’t cost any more than mosfets. People are charging more for GaN amps because it is the latest buzzword and they are first out so they gouge you. The EPC GaN fet recommended by EPC for audio use costs $1.05 each at 100 quantity. Hardly expensive. At the most 4 per channel....so that is $9.

GaN amps will be available from China for a few hundred dollars.....I have no doubt. However, they have to design the circuit from the ground up.....so will take a little while to come. The big manufacturers are slow and conservative (Hypex, IcePower, Pascal, etc.). It takes a sledgehammer to get these guys to try something new and then it takes years for them to develop it. It will be just small companies for awhile with GaN amps.....but hopefully, the big guys will get on board. TI and Infineon, etc. make class D amp chips as well. Maybe they will be first to come out with a GaN version......then you will see things like this:

https://www.alibaba.com/product-detail/IRS2092S-Mono-Channel-Digital-Amplifier-Class_62169638554.html?spm=a2700.pc_countrysearch.main07.99.3d202a3c3TR7hg

The above is an Infineon class d driver and some IRF mosfets.....cheap enough for you? Maybe the 2092 can drive GaNs? Fun stuff ahead.

Personally, I think it's a horrible thing to price out a product based on component costs.

I think everyone would be horrified if we did this consistently across audio.

There's more to a high frequency design than the cost of the transistors. PCB layout must be done meticulously, and test failures common, so R&D matters.

Still, having said that, Class-D amplifiers are quite good already. Better than some Class A amps, worse than some Class A/B.

If there are actually audible benefits to GaN based amplifiers I look forward to hearing them.

If there are actually audible benefits to GaN based amplifiers I look forward to hearing them.

There should be. GaNFETs are generally faster than MOSFETs (although MOSFETs aren't done by any means) and so the use of GaNFETs means you can run the amp with less dead time. Whether a designer takes advantage of this fact is another matter but generally speaking GaNFET amps should sound better as they have less distortion on that account.

Whether a designer takes advantage of this fact is another matter but generally speaking GaNFET amps should sound better as they have less distortion on that account.

@atmasphere

As you are well aware, I’m kind of touching on an issue of specmanship that that affects us with all amps. Can we hear "better" when you go from 0.01% distortion to 0.001%? I know distortion can be reduced, which technically means more fidelity to the input signal. What I don’t know is that this alone is audibility, let alone desirable.

Like Tube amps, or Pass (who makes it clear this is his goal) the distortion profile may have more to do with euphonic capability than merely lower distortion.