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

Heatsinks are required, even for Gan devices switching at lower speeds
If you ran this thing under heavy conditions, it would fail

And yes Gan devices have their own heat pad underneath which is sweated to the ground plane of the PCB. But that will be in every case that they are used in, your not going to twist it any other way.!!!! https://ibb.co/jTWd9nx

I tend to believe the manufacture of the board, EPC and it’s designer Steve Colino, who stated only heatsinking is required on these GaN devices if the switching frequency is raised. Not by what you say.

And from Merrill Audio who use the higher switching speed

" Internally the Element 118 Power Amplifier Monoblock PCB boards are manufactured to the highest excellence available and further engineered for sustaining a most stable temperature distribution. Using 8 pounds of pure copper per monoblock, the highly refined heat distribution system maintains a steady temperature environment on the PCB boards, a condition absolutely essential for linear operation."

I've ordered 4 Class D amps today to add to my listening list. I'm looking forward to stripping them down and tuning them up.

Have a Liston to the new Nord Acoustic class D amps with the REV D boards your forget about hearing anything else they sound amazing, you can also tailor the sound to suit your personal choice by changing the op amps, the op amps are all very cheap, its called op amp rolling.

And from Merrill Audio who use the higher switching speed

" Internally the Element 118 Power Amplifier Monoblock PCB boards are manufactured to the highest excellence available and further engineered for sustaining a most stable temperature distribution. Using 8 pounds of pure copper per monoblock, the highly refined heat distribution system maintains a steady temperature environment on the PCB boards, a condition absolutely essential for linear operation."

George, looks like you made my point.

I tend to believe the manufacture of the board, EPC and it’s designer Steve Colino, who stated only heatsinking is required on these GaN devices if the switching frequency is raised. Not by what you say.

Well you're not likely  to be designing a class D amp anytime soon, so its no worries for you. For those that **do** design such amps, the idea of no heatsinks is scary to say the least, and the prudent designer that knows the amp is going to see some thermal abuse in the home will add heatsinks. To not do so is to court disaster- If it turns out that a model is overheating, the boards in the unit will have to be redesigned and that sort of thing can put a company under really fast.

George, looks like you made my point.

As Steve Colino of GaN (EPC) has said below, there is no need for any heatsink on the GaN transistors if they are used at todays switching speed. Only if you use the option to raise that switching speed to gain the extra sound quality, then there is the need for a heat sink to be mounted to the GaN transistors, as in the Merrill and Technics case.
Once again you twist things, "it’s not a good look" if you try to put s**t on this new technology while your trying to release your own Class-D amps.

Excerpts from Steve Colino’s email to me.

V.P., Strategic Technical Sales

EPC (Efficient Power Conversion Corporation)

"EPC9106 GaN FET we were able to get outstanding sound quality in the amplifier without heatsinking.
Our GaN FETs will give an even higher performance difference compared to MOSFETs in both sound quality and efficiency at 1.536 MHz switching speed.
The eGaNAMO2016 is a GaN FET amplifier platform that is capable of delivering a very high performance 200 W into an 8 Ω speaker load (400 W into 4 Ω) [8]. Its 96% system efficiency without requiring a heatsink.
You can take the value in sound quality and eliminating heatsink assembly costs while delivering your customers increased efficiency is a smaller form factor."

https://www.digikey.com/product-detail/en/epc/EPC9106/917-1090-ND/5036827

" THERMAL CONSIDERATIONS With this high efficiency, the EPC9106 design allows for the complete removal of any classical or historical heat sink requirement. This elimination of the heat sink also reduces the potential contribution to radiated EMI/EMC emissions.