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?


celander
I suppose I should add the AGD is not made from any silly module whatsoever. Modules are made so guys that cant design digital can still make amps by creating an input section. Ive got no respect for modules in a box, unless I hear about some very innovative front and with some very interesting software they wrote.

(here comes a rant, youve been warned)
I must say something about this amp (not the guy) the top of the line Merrill at 36 K per box.. dont you guys think this kind of crap is ruining the industry ? Dosent Dan have an amp thats near $200K ? Give me a break.. Those are the designs of scared people that thier meal ticket is ending so kick some Dubai Sultans under the robe before they go. Cash grab before the grave type thing.. Because it is ending. HiFi the way youve known it is on its way out, and class D is coming whether you like it or not. Eventually EPA will stop the production of Class A as an energy waster, just wait and see..
Finally back top Merrills top of the line is it just me or is that 36K box made from plate aluminum screwed together with more plate in smaller pieces put on the sides, 2 squiggles put on those plates to distract design neophytes, a set of outriggers in chrome which serve no mechanical purpose (they are meant to keep tall things from tipping over) again, distract the folks that dont know design, then make it a weird color. To me this company has just exposed how little they know about aesthetic, or how strapped they are for cash to do proper aesthetic, but to have the Gall to price it at $32K ?? now you are going to make true lovers of high design blow off our industry. Look at the AGD, 1 inch thick billet walls with no seams, and a smoked underlit Lexan top with a freaking output stage in a KT88 envelope !! Say what ?? yes, he "ship in a bottled the complete output section into a empty KT88 tube and its pin correct for operation. This is an infinite number of iterations you can easily do yourself. You dont buy a new bigger amp, you buy an output tube with a digital GaN engine inside. Theres no way to blow these but lets say you invent one.. so what ? change the tube out to fix your blown amp. If you dont recognize innovation when it kicks you in the shorts then I can not help you. This amp is clearly something new. Nobody has ever seen anything close.  you want a plate aluminum amp screwed together for $36K as something new, I honestly don't think that's ever been done either.. which type of innovation do you respect ? Lets get priorities straight people !  Look at Jeff Rowlands amps, I dont really think the comparison is fair because he still uses silicon, but I respect his method. He represents the tried and true. he will let everyone else step on their noodle while he sits back and watches and calculates. He moves on well proven tech only. Partially from going to early on new tech in his earlier years. Older and wiser. His 535 are only $6K, crap, his 125 are $3K but still come out of a machined single block of aluminum. There is no better chassis ive ever seen than milled billet. I will keep most of my focus on GaN since I abide by the posters desires, but These GaN amps better my Class AB Rowland amps in the clarity and articulation of upper mids and highs on complex music and the bass is out of this world, yet there is one area the Rowlands dominate, and I will check this more, and thats the upper bass, lower mid area.. Male vocals for instance.. a little fuller in the body in that specific part of the freq range only. I imagine  tuning may fill this area of the AGD, but if I did not AB , I would be extremely happy with AGD  Merrill is the only other contender with GaN and Id be happy to compare. I honestly dont think manufacturers even care about these little squabbles

so theres my .2c
M
Eventually EPA will stop the production of Class A as an energy waster, just wait and see..

I'm pretty sure they'll want to ban bit coin mining long before they pay attention to the nearly extinct audio enthusiast.

Best,
E
But These GaN amps better my Class AB Rowland amps in the clarity and articulation of upper mids and highs on complex music and the bass is out of this world
I don’t condone dealers giving their "two bobs worth" on what sound better than what, especially if they sell the equipment, but this is a dealer that sells Rowland Research


The little thing that brings life, and I mean life in the way that you sense a human in the room with you. Normally this comes with borderline stridence. Never have I heard a top end so defined and smooth at the same time.
This is what Gan Class-D Technology is all about, getting the upper mids/highs right, that so many have questioned about, with today’s/yesterday’s Class-D technology.


I would be extremely happy with AGD, Merrill is the only other contender with GaN and Id be happy to compare.
You could probably add both GaN based Technics to that also, the SE-R1 and SU-G30

Cheers George
I',m back, after just completely putting the GaN amp at a disadvantage. Its 100W at 8Ohm and I put one amp each channel whereby I took the midrange driver lead from my outboard crossover and put a full .7 Maggie on it rather than going to the 3.7i panel. My purpose was to find the line of the AGD and I did of course. Whats nice it the channel just stops music, when you turn it down it comes back. So you will not damage the amp or speaker with this kind of protection so thats cool. I would say that the Vivace monos would be perfect with speakers 90db and above. The articulation and quickness would be very well matched.

By the way, I'm not a typical "dealer" per se.. Im a manufacturer, founder of Verastarr AudioFoil Cables. Thats my main thing but when my users want to buy ancillary equipment, I like to be ready to serve them without skipping a beat, so if no client is asking, I'm not advertising gear whatsoever, unless its used or demo, I'm moving out.
George, isnt the Technics like $30K or something ?
Anyways I'll go back to testing the GaN with something its own size to be fair.. So like a Rowland 125 actually at $3K.. seems off  but its the truth..

George, have you spent any time with Rowland amps ? Forget continuum, it seems to be a sore spot,(im sure there is more to that design we cant see and I'll share any info I get, plus If I needed to i could expose a myriad of other top level HEA companies using drek inside. Ive got to believe there is more to it because if youve ever met and spoken to Jeff, hes not the sheister , hustler type whatsoever, its quite the opposite. As a total kid/ newbie, I remember Jeff was the only HEA  Icon who looked me in the eye and listened to what I was saying. To this day he still does this for anyone that speaks with him, which shows great respect for his fellow human being. I also know Mark Levinson and God Bless him hes got a different way, 100% entertainment for me to watch, but Mark is from the streets of NYC, Jeff is up in the mountains.. so you catch my drift... You do however make an interesting point.. I will get to the bottom of it.  Meanwhile  I'm happy to ship one of Jeffs amps for you to try out in your rig, I am a real picky SOB and they are very well built and great sounding.
All the best.!
I',m back, after just completely putting the GaN amp at a disadvantage. Its 100W at 8Ohm and I put one amp each channel whereby I took the midrange driver lead from my outboard crossover and put a full .7 Maggie on it rather than going to the 3.7i panel. My purpose was to find the line of the AGD and I did of course. Whats nice it the channel just stops music, when you turn it down it comes back.



I have no idea what this paragraph means.