Gallium Nitride GaN Class D Amplifiers


In my recent research for a possible upgrade to my current amp (Benchmark (AHB2) I was reading about the new higher end design for Class D. I'm very interested in learning more about these new GaN(Gallium Nitride) designs. Three companies are offering some very well reviewed products and they are not going crazy with Watts per channel:

Orchard Audio offers a 250 watt Amp

AGD a 100 watt

Atmos-Phere also a 100 watt

What's interesting  is while Orchard is a new company AGD and Atmos-Phere have been around a while producing high end Tube amps. In almost every review it is noted how these newer designs sound like Class A or Tubes with all the benefits of Solid State. One reviewer couldn't go back to his tube amps after extended listening to the Orchard. No wonder AGD and Atmos-Phere are getting into this technology. It's very exciting as these amps are highly efficient turning over 90% of the power they draw into sound compared to about 78% with A/B designs and I believe even significantly lower for Class A. They run cool and usually weigh between 10-28lbs. I plan to do more investigation. Small size and light weight with decent power is very attractive. There are also mono block offerings for more power if needed. These are not cheap Class D products. They are well designed and constructed.

Orchard Audio's base model is around $2700and their Dual mono version with larger power supplies is $5500.

Both AGD and Atoms-Phere are $5000

Mono blocks for each are about twice the cost.

Has anyone had any experience, demos, etc ., with these types of GaN Class D amps?

 

jfrmusic
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I play the Technics SUG 700-2 which is around $3,000. It looks and sounds great I can't imagine anything sounding better.

Technics SU-G700M2 integrated amplifier | Stereophile.com

I don't represent Orchard, to make sure that's clear. I recently pulled the trigger on Orchard's Starkrimson Ultra 2.0 DIY kit with dual power supplies. So it is technically the DMC. It was a breeze to build and the questions that did come up, Leo was there to help and he is a pleasure to deal with. It is refreshing to be able to speak with the designer behind the equipment like Orchard, Rogue, Southerland, to name a few. There was a question earlier about being balanced, they are , but he has an adapter available if you choose to go that route. I am driving it with a Rogue RH5 preamp with Telefunken NOS 12au7 tubes and Martin Logan XT F100 speakers. Soundstage is deep wide and tall, separation between instruments and vocals very impressive for half the cost of the competition. And no sub needed.

GaN FETs are for high frequency (>500 kHz) switching circuits and are not really meant to be run in saturation with a Q point.  They have low parasitics, but that only applies at high frequencies, not audio.  Using them is more marketing than any intentional advantage over a MOSFET.  There are too many other factors involved to attribute sound quality strictly to the output devices.