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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
erik_squires
5,268 posts
 
The overshoot is a common cause of the hard edge found in a lot of solid-state equipment.


Not even apples and oranges, this is apples and couches.

What evidence or experience do you have that this particular issue is indicative of this audible problem in a linear amplifier?

Next, since these overshoots are at an even higher frequency than the switching speed, maybe by 10x as much. A 400kHz switching speed, with some ringing, would probably be in the 4 MHz range. Based on what experience do you attribute this particular issue to a particular sound quality in what exact Class D amp?

Because the last thing my Class Ds have is hardness, did I get lucky?

Best,
E
georgehifi's avatar
georgehifi
4,966 posts
 
mallard1
I was blown away and could not stop to listen these little things. I must say I was used to a Nelson Pass F5 Turbo (pure Class A) and I always were happy with the F5 but the GaNTubes have blown it away. In every aspect, especially the mid-highs they distribute so much... lets say 3D sound. I was just astonished about the difference to my F5. It feels like you can grap
every single instrument or singer in the room. Just fantastic! If someone has the chance to listen to the AGDs I can only recommend to take the time and do so, it will be a great experience.

And welcome to you.
This is a very eye opening review with comparison to a very highly regarded Pass amp.
If this type of review/comparison stays consistent with other reviews to come, looks like my boat anchors may go up for sale before the want/need drops out of the market for them.

PS: Good to see Merrill audio giving us info on his GaN Element range, and why GaN technology Class-D with it’s superior switching speed and dead time is going to finally bring Class-D into the hiend proper, with no question marks on the upper mids or highs.

Cheers George
georgehifi's avatar
georgehifi
4,966 posts
 

Because the last thing my Class Ds have is hardness, did I get lucky?
Only with your own hand.
Post removed 
celander's avatar
celander OP
1,036 posts
 
+1, Mike (OCD HiFi Guy) Powell, for his contributions here. Mike always impressed me as a straight shooter, no bs, kinda guy. I’m one of his clients, so call me biased. 
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