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

The benchmark is top notch.  Nothing wrong with the others using GaN but hard to call a clear “upgrade”.  Depends on the specific amp not what transistor technology used and what you prefer mostly.  Atmasphere and AGD are popular with tube amp lovers otherwise.    GaN has advantages but alone does not guarantee “better” at least based on objective measures alone. 

A friend of mine brought over a set of AGD monoblocks to try in my system for an afternoon. They performed extremely well for their cost (?$8K). Natural sounding and dynamic. I was comparing them against my Audio Research Reference 160m monoblocks. With the rest of the system being Audio Research Reference, the substitution was not a huge difference in sound quality. The AGD did not render the treble as well.. but for the price great deal. I would probably identified more differences if I had them in my system for much longer… but they did a good showing for themselves.

The reason I mention that the rest of my system did not change is that if you substitute one component of a carefull crafted synergistic system and substitute one component, it can often maintain its character. But switch two or three and the whole can fall apart.

@jfrmusic, the dual mono stereo (DMC) unit is $4000, not $5500.

I do sell ultra monoblocks as well that are more expensive and can be configured to be $5500.

Reach out with any questions.

@tvad 

 

Since you have had direct experiences with these two amps I would be very interested in more specifics of the SQ and character of the Atmosphere and AGD amps. .Did you auction the AGD Tempo or the mono blocks?

@mapman 

From the many reviews theses amps may provide a more Class A / Tube like sound character which would be attractive to me.

I had demo of Atmasphere Class D followed by Atmasphere tube amps at CAF 2022. The two sounded more similar than different so that is a good omen for the tube amp camp.

i also heard AGD at another Audiogoners house who also ran Linear Tube Audio amplifier. LTA is a tube amp that does tubes in a way that resembles very good SS or Class D amps in general. Very good sound but more towards the tonally neutral side. Atmasphere amps have just a bit more touch of tube like “PRAT” which many audiophiles will find very desirable and harder to find outside of actual Tube gear.

 

@jfrmusic of course the speakers matter a lot as well. Did you mention what speakers you are running? Thanks.