High end Class D amps?

Technics GaNFET: Dry, sterile, boring. Burned it in for over a month. The cheap integrated unit.

I don’t claim to know all the Technics GaNFET units, but I am not aware of a "cheap" integrated unit and considering you are using relatively "cheap" Odyssey Stratos, I am not sure what you consider cheap. Even a new Cherry is a fair amount more money than a standard configuration Stratos. Do you mean the G700 which I don’t think uses GaN. SU-G30? .... that is $4,000.

I don’t have the engineering chops to add much to this discussion, and neither do I have a dog in this. It would seem to me that much of this difference of opinion might be about the theoretical possibilities vs.actual consumer available units that have actually been measured to offer those theoretical possibilities. My limited experience with Class D amps suggest quite a bit of difference between competing units, and though to this point none have convinced me to switch from standard ss amplification, I am truly excited by the potential of Class D (or whatever variation therein) amplification.

It was the SU-G30. I bought one used for $2500 if I recall. I meant cheap in relation to the other Technics GaNFETs. The Stratos was picked up as a "filler" amp until I get get something better like a Mark Levinson, Esoteric, etc., but they worked so well with the ProAcs that I haven't been in a terrible rush to move on.

I think I stated earlier in this thread that I used to own a pair of Nord Hypex NC500 monoblocks. There was a lot to like about them, and I think they delivered compelling performance for the price, but were not as engaging as I was looking for in the system I had at the time. But they convinced me that class D holds a lot of promise. 

In the past year, I've had a lot of fun building DIY electronics (two pairs of monoblock amps and a preamp so far), so I've decided to try building a class D amp as my next project. I like monoblock amps for a number of reasons, so this project will be another pair of amps. I'm using the Purifi modules, and using a high-current linear power supply (1500VA) for each amp, and leaving room in the chassis to experiment with different input buffers. 

This probably wouldn't be cost effective for a commercial product, but that's what's fun about DIY. 

I'm going to use the Neurochrome buffer to start, but I've already started designing a buffer with a single-ended class A output that I'll try for round two. I've got a few other ideas in the works for other input buffers as well, so I can hear for myself how they affect the sound. 

I hope to be playing music with the Neurochrome buffer by the end of the month. 

jaytor I think I stated earlier in this thread that I used to own a pair of Nord Hypex NC500 monoblocks.
In the past year, I’ve had a lot of fun building DIY electronics (two pairs of monoblock amps and a preamp so far), so I’ve decided to try building a class D amp as my next project. I like monoblock amps for a number of reasons, so this project will be another pair of amps. I’m using the Purifi modules, and using a high-current linear power supply (1500VA) for each amp

Interesting as this is what I have with a monoblock pair of NC500 modules.

Which impressed me and are in the Belcanto Ref 600M’s for class-D driven into a two way with Rahl ribbon, a very easy benign 6ohm load.

So these NC500 module (which btw are the ones in the Belcanto Ref 600M’s) are also in monoblocks but using big linear supplies and fed direct to their balanced input their input via the MSB R2R Discrete’s balanced variable 10ohm output so no need for any input buffer board. These sound even better than the BC Ref 600M’s. On those Rahl based two ways.

On the main system these NC500 mono’s have great bass/mid bass (very low bass is still bettered by my big ME bi-polar linear monoblocks with more weight substance to it) same as this amp but set 30w bias and no Class-A switchablity.
https://ibb.co/QnYhmzL
https://ibb.co/zb8vCgR
Upper bass is the equal of the ME’s as is the lower mids (male voice). And then this is where the bigger difference starts, there seems to be a disconnect in the upper mids and highs from the bass with the NC500’s like they are two different amps doing bass and mid/highs.
I’m putting it down to the switching frequencies output filters phase shift that reaches down to 1khz!!!! as can be seen in the phase shift plot in the graph of Class-D’s https://ibb.co/NC7sC8T which in this case is still -25 degrees at 1.5khz!!! and -75 at 10khz!!!!!!!

And this is why $$$$$ Technics with the GaN based, linear supply, SE-R1 I believe have the answer by increasing the switching frequency 3 x’s to 1.5mhz so then the filter can also be raised by the same amount and hence the phase shift goes up by 3 as well out of the audio band.

Cheers George