GaN-based Class D power amps

OK, I didn't want to weigh in because I get hot under the collar with knowitalls that have never owned nor listened to that of which they speak. So I will in usual style speak about ONLY things that Ive listened to in MY RIG in MY HOME. anyone else is just bumping their gums from boredom. or guessing, speculating, fantasizing, or otherwise just stroking.
I make it my business to speak from first hand experience, anything else regarding ones opinion of the efficacy of any given product is not welcome in HiFi as far as I’m concerned. Time to change the playing field, and make forums something respectful and honorable. Unless you wish to kill the industry which is very much the way it looks. Newcomers read crap like this and run away from us. so gather up sit down and listen.

I have 4 AGD monoblocks as we speak, because I biamp. I also have 2 Jeff Rowland 625 S2’s because they are a top level class AB reference, I have 2 Jeff Rowland 535 amplifiers since they represent the first class D to fool me into thinking I was listening to Class AB. these can be bridged for 900WpC. Next week I will receive a tweak from Jeff that catapults them to new levels once bridged.

So I speak from experience and furthermore I Prove myself by making videos and recording the differences in sonic so you guys can hear for yourself. OCD Hi Fi Guy on youtube. There you wiill find the veteran industry guy that is paid by no advertiser, and owns my company, so I say it the way it is.
So to give Ceelander what he asked for in the first place, I will share my experience with these amps.

The AGD GaN amp is unlike anything Ive heard so far in HiFi. It literally took me aback whereby I had to relax and calm myself to wrap my head around what I was hearing. Complex music at high volume with the most articulate top end ive ever heard. This means things that normally can be a touch smeared are now perfectly discreet all in their own place, to me this is an indication of stunning speed and accuracy. I played torture test pieces that normally hurt, that were so clear without edge it bewildered me. This is something I did not think was possible. I love defined leading edge in my playback. It is the very thing that brings clear 3 dimensional rendered images into my soundstage. 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. (speakers are heavily modified Magnepan 3,7i with custom sub towers on channel 2 crossed at around 90 with a 12)Bass.. let me be a New Yorker for a second.. You can friggin fuggedaboudit.
Tight and tonally correct, musical even. Mids clear and liquid to the point that I got nervous about my beloved Rowland Model 12 .. when I first tried the AGD’s I had 4 Rowland model 12 monos. I got so unnerved by AGD, I sold them and bought a brand new pair of 625S2, the amp that in Jeffs words when asked replied "Ive taken Class AB as far as I can take it" even if I beat these amps out I’ll keep them as my example of AB at its highest.

im starting to get freaked out because this is getting very long and ive erased full pages like this so I’ll post and start a second

Cheers
Mike Powell

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

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.!

We are testing different input impedance values for the best result in all situations. .Once the final number is settled on I’ll let you know..

@ George, you know that there is a customer base out there that will not buy basic box components. There are also designers with design aspirations beyond rudimentary boxes of bent steel sheet metal. Being that I am a manufacturer and dealer I have plenty of buyers that do not buy anything that looks like a sheet metal box .So there is nothing wrong with a pretty box at a premium price. You must absolutely hate fine art. You know that Rembrandt is just antique canvas and old wood framed up with a few pence of oil and pigment. Levis jeans are $50 and they are the same dang thing as a Chinese pair of denim jeans for $15. As an importer of the best Chinese audio product currently being made in many peoples opinion, I can tell you this. Chinese tune product differently than America and Europe. You can have a dead nuts clone from China of a DartZeel and it will not sound the same. Plus there is this thing called pride of ownership. and some of us have it. Ive spent a good amount of my career trying to find the Chinese equivalent to the world class or even semi world class, and Ive not been able to find it. Look, the same things piss me off that piss you off. For me though it has to be more blatant, Like a $36K Mono with a chassis cobbled together using everyday, off the shelf parts. again, we could pick anything apart we want to as a waste of money. So some people want $2K Monos with a basic box from China, others want something with similar parts but made in USA and produced inside a piece of functional art. Neither one is wrong,.So please lets not vilify those that value different features than we do. These forums have a very bad reputation for crap talking bordering slander that ends up crippling this place for use as intended which is to be a place where new audiophiles can come and feel welcomed. As well as where manufacturers and dealers  can interfece with the potential buyers without fear of damaging allegations or otherwise generally negative comments about us. Its why I rarely come here. We already fight the stigma of the 1980s stereo salesman, lets not keep that crap alive, I say we snuff it here and now. We will all come down for a walkabout with our favorite Cobber and sit around the campfire eating Barramundi, OK ? .

Is there a possibility some of us like beautiful chassis without being douchebags ?

LOL< great, because I am a big fan of nice chassis work since it is rather scarce.  Now thats 2 about the rack in the center. Ive got a rack to the ceiling dead center of the front wall.  This is because my rig is also my showroom. So at any given time I have a bunch of different gear different types of circuits or classes of audio so I can demonstrate for people. Personally I would love an empty room with nothing but 2 speakers, everything hidden. I do not like a cluttered look for myself personally. At one point just for the heck of it I will go ahead and move that rack because it's on wheels and if it's not night and day different it's gonna stay there. The thing is speakers are 5 feet in front of the rack so there's nothing in between the speakers furthermore I like my image to come forward from the baffles as well as go back. I do not like the typical audiophile sonic that just only goes back.