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

Yes, really bad measurements usually correlate to poor sound.  However, most all Class D amps measure fine (low distortion, high damping factor).  This is my point.  You were asking the person whether they were going to measure the amps (all Class D).  This is what I was responding to.  Almost all Class D amps measure pretty darn good.  The Ncore amps measure better than most but are now taking a sonic back seat to the new IceEdge modules that measure great, but not as great as Ncore.  Another words, the measurements have nothing to do with the sound in this case......in fact, the cheaper Ncore NC400 measures slightly better than the expensive NC1200 but everyone says the 1200 sounds better.

Some tube and solid state amps and some zero feedback amps measure poorly......and usually this has a sonic result.  However, even some not so great measuring amps (Dartzeel and DAgostino, for instance) have a reputation for great sound in many ways. 

The new Relentless amp from Dan does away with the not so great measurements.  He uses over one hundred output devices to get low output impedance and super matches the front end so he can achieve low distortion numbers without feedback.  I am sure it sounds outrageous.....at a quarter of a million dollars, it should.  Dan makes his own output binding posts out of big hunks of brass......brass?!?!?!?!  Brass is very sonically lossy.  Why not Tellurium copper, or pure copper or PCOCC copper or silver or whatever.....but brass?  You pay $250,000 for amps and they have veiled output connectors.....yikes!  However, even the input connectors are $5 brass Neutrik connectors.  How much better would the amp sound with my binding post bypass system and some better sounding xlr input jacks?.......noticeably!.....and it would not measure any different.

All the tweaks and mods I have done to the IceEdge module do not make it measure any different......but the aural distortion has gone down tons.  You must listen.  Measurements can tell you very little of the actual sound.  Two amps that measure the same can sound worlds different.....so the measurements have no correlation to the sound.......they don't tell you how it sounds! 

Just changing the fuse, footers, shelving and power cord on an amp can give incredibly different sound.....none of which shows up on a distortion test.  This is just the beginning....there are tons of things one can do to lower the aural distortion in an amp that have nothing to do with measurements.....this is how it always was and always will be. 

Measurements are fine.  It is good to have good measurements (I certainly prefer better measurements)......but it does not tell you how it sounds.

You cannot read the distortion measurements posted on some Stereophile review and know how an amp will sound.  All amps with decent specs will sound different.  You could have an amp with really high damping factor and it sounds not so great in the bass.  You could have an amp with really wide bandwidth and the highs are not worth writing home about.  Every single thing in an amp will add its sound.  One super bad resistor or whatever and BAM!.....there goes the transparency.  Here is an interesting fact.  Heatsinks ring.....yup.  If you take your fingernail and scape it across your heatsinks and if they ring then you are adding that sound to the amp.  Many people have tried damping their heatsinks on my suggestion and all of them are amazed at the sonic benefit......less "transistor sound".....he he....or should we say less "ringing heatsink sound".  Again.....not measureable.....but certainly audible.

I am not against measurements.  They can show you if you have a serious problem.......and some distortion artifacts (predominance of even or odd order, for instance) can be audible.  But obsessing about measurements?  Not in this house!  I want goosebumps.......I don't listen to a distortion meter!

I am not against measurements.
First you say "Measurements mean very little"

But obsessing about measurements?
No ones obsessing as you say, it's fact they are important for good synergy between components. 

I don't listen to a distortion meter!
And now your just being ridiculous, because you have nothing to say

And what have you to say? Come on, you just like to be right and argue and have the last word. I try to inform. I think my post is very informative. I think it will help people. There is probably someone right now damping their heatsinks and getting better sound.  Will your post help people?

There is probably someone right now damping their heatsinks and getting better sound.

 That one smacks of snake oil. And you say  "Measurements mean very little"  really!!!! 
Hi,

Let me be very clear because for some reason there are certain people on these forums that love to argue and scrutinize every single word you say. We do not measure any equipment but what we do is directly A/B products against each other in 6 very different systems. The only thing each system has in common is the cabling.

The question was asked " anyone listened to or own any of these amps" and the answer is yes, someone has actually listened, owned and A/B some of these amplifiers. The main reason we do not give our results is because we do not want to get into disagreements with people that have not done the exact same A/B testing or people that just come on these forums to argue. Truth is we are just a group of guys having fun and I intend on keeping it that way because that is really what audio should be, FUN!