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?



I have both a LSA Voyager 350 GaN amp and a EVS 1200 IcePower 1200AS1s. Both are dual mono in a single chassis. Both are excellent, and as good as any of the many amps I owned over the decades be they tube or SS. Sadly, the EVS is no longer made, but the Voyager is and it's a real bargain (MSRP ~$2700), AND, Ric Schultz modifies them


I owned the AGD Gran Vivace and they were spectacular. I had an Aesthetix Calypso linestage (tube) preamp in the chain and it was the best sound I've had in my room to date, save for one aspect - low end (reverb). Back to this in a second... what set AGD apart from the others is that they purchased all of the GaN modules that were designed for audio applications whereas all others only had access to modules for other purposes. I do not know if this has changed, but it seemed to be a true story a year or so ago. Back to where GaN fell short for me -

Enya "O Come, O Come, Emmanuel" - Opening deep synthesizer and second, John Rutter: "Pie Jesu" around the 1:02 minute mark. Both are Qobuz. What is missing? Power and emotion. My question is, why? I do not think other amps are embellishing the sense of power and scale. I am wondering what it means that GaN is not accomplishing the same? Is it more accurate? Controlling the drivers too well? 

I have had Audion MK 3’s for a few weeks now. It is the most educating experience I have ever had with a component. The difference that different cabling makes is much more apparent than it used to be. Moving around different brand cables within the component mix results in some quite unexpected advantageous relationships which were not so clearly audible in previous set ups. These modifications extend throughout the component mix.

The amps also very quickly educate you about what treatment the listening space requires. "Room nodes" are now distinctly audible to me across the spectrum. Bass nodes in particular are now more obvious as to where they are in the room and where treatment should focus.

With these amps volume can be turned up higher without bleeding the music or wearing the listener out. I feel that I have been learning more things about musical reproduction in general.

Interesting, @izjjzi. I have the stereo AGD and feel the same about the bass. The sound is as good as anything I’ve had but the bass is light compared to others...or is it more truthful? I think it’s tad light but everything else about it is spectacular. Alberto, the owner/designer, sometimes chimes in around here as does Ralph at Atma-sphere. Maybe that’s how they sound so good everywhere else in the spectrum. SET’s often have the same issue, but I thought that was due to power. The AGD’s can handle difficult loads like Maggies and Quads.