GaN-based Class D power amps


The use of GaN-based power transistor tech is now emerging for Class D audio power amplifiers. Seems appropriate to devote a forum thread to this topic. At least 3 companies have commercial class D amps in their books:

Merrill Audio, with their model Element 118 ($36k per monoblock, 400 W into 8 ohms, 800W into 4 ohms), Element 116 ($22k per monoblock, 300 W into 8 ohms, 600W into 4 ohms) and Element 114 (coming soon). 
https://merrillaudio.net

Review of Element 118 at this link:
http://www.enjoythemusic.com/superioraudio/equipment/1018/Merrill_Audio_Element_118_Monoblock_Amplif...

ADG Productions, with their Vivace Class D amp ($15k per monoblock pair, 100W into 4 ohms). (The designer emailed me indicating he has another product in the pipeline.)
http://agdproduction.com
Review of the Vivace Class D moniblocks at this link (warning: link might not work (1/11/2019)):
https://positive-feedback.com/reviews/hardware-reviews/agd-production-vivace-gantube-monoblock-ampli...

Technics SE-R1 Class D stereo amp ($17k per stereo amp, 150WPC into 8 ohms, 300WPC into 4 ohms) 
https://www.technics.com/us/products/r1/se-r1.html
Preliminary review of the Technics SE-R1 at this link:
https://www.stereophile.com/content/technics-se-r1-digital-amplifier
Technics also has a lower priced GaN-based class D integrated amp in their catalog:
https://www.technics.com/us/products/grand-class/stereo-integrated-amplifier-su-g700.html

Anyone listened to or own any of these amps?


PreviewAg insider logo xs@2xcelander
Once again the seminar lecture if you missed it.
From Electronics Foundations: Semiconductor Devices
[Lecturer] BJTs tend to have better, more linear gain characteristics…and can give you a lot higher voltage gain than MOSFETs.…They’re also able to handle higher output currents…and have a lower output impedance.…That gives BJTs a huge advantage over MOSFETs…for building amplifier circuits…that need to provide a significant amount of output power…and or drive loads that have low input impedance.…MOSFETs are going to have a harder time…driving a low impedance load…because they have a higher output impedance.…


And if you can’t understand that then in my book you and your maths are worthy of being ignored, end of story.

@georgehifi  Do you get why this passage you quoted is is completely irrelevant (i.e. has nothing to do with the conversation)??

I did not catch from your posts the brand of speakers you were using. Please remind me again?

@celander I’m using the Technics speakers SB-R1, as I said before I get a great deal from a very good friend who sadly went out of business... 
@morellihugo, Thanks for your reply, as I feared my query might get lost on all the banter back and forth with Audiogon's favorite Aussie contributor. Lol

I am not familiar with that speaker. I am glad you enjoy them. 
And when is Ralph's class D amp going to be released, regardless of transistor topology? Asking for a friend...