Gallium Nitride Class D Amplifiers

[JFRMusic]

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?

 

[Republicoftexas69]

Overlooked the Gold Note PA-10 That is also well reviewed and GaN. The monoblocks will set you back $4000.00
TECHNICAL SPECIFICATIONS

MAIN FEATURES
POWER OUTPUT

75W@ 8Ω and 150W @ 4Ω per channel, 600W @ 4Ω per channel in mono (BTL)

FREQUENCY RESPONSE

10Hz-30kHz at +/-1dB

TOTAL HARMONIC DISTORTION (THD)

0,05%

DAMPING FACTOR

high (250) or low (25)

 

[Bones13]

I chose Atma-Sphere ”Class D” monoblocks ($5,400 for the pair IIRC) they were designed, and built, by a veteran in the OTL tube amp arena. Ralph designed a novel circuit, and fronted it with a standard linear power supply. The amps are 12-14 pounds each, and accept RCA and XLR inputs. There are no 12v trigger circuits, but the power button is in the front. They were available with silver, gold, or black front plates back when I got mine.

These do not have any digital glare, nor mushy tube signature. Coming from DIY firstwatt Class A amps, the Class D amps are just a tad on the warm side of neutral.

They run cool and quiet, no thump at start up or shut down. I love mine.

 

[Socrates428]

I've owned many excellent Class A SS and tube amps, plus the Benchmark amp. I've also heard the AGDmkII at length and Atma-Spheres at shows. The GAN amps are very nice, although underpowered for my speaker needs. I'm hoping for higher-powered variants soon.

Until then...I bought Hypex Nilai monoblocks as a summer heat/electricity saver in place of my space heater amps, yet am dumbfounded by how great these little amps sound. I very much did NOT like any of the prior Hypex amps, and the Nilai sounds nothing like them to me. The Nilai seems to combine the detail and clarity of the benchmark with the power and ease of flow of big Class A amps. It is grainless and controlled, with great sound staging and utter blackness around instruments/performers.

The Nilai, as with the GAN amps, is not at all thin, yet nor are they as dense/round/bloomy/liquid as tubes, but really nothing but tubes really ever is in my experience (it's a lovely distortion/coloration in the right dose and for the right types of music, no question, which is why I keep tubes in the system and spare tube amps at the ready when the mood hits). The Nilai lets upstream changes more clearly show through while having a tremendous yet seemingly effortless grip over the speakers from top to bottom, which is something I've only heard the very best tube amps do (i.e., VAC Statement).

Just another contender to consider in the next-gen amp camp.

 

[JFRMusic]

Yes I did consider number of these newer Class D amps but once I heard the new Accuphase P-4600 amp I bought it. It's slightly on the warm side of neutral, very detailed with a clean smooth high end and a wide and deep soundstage. It really is one of the most beautiful sounding amps I've heard. Not solid state sounding and not as warm as tubes.It's somewhere in between. You really have to hear it to appreciate it. It's on order and I hope to receive it by end of April. It does weigh 66 lbs but my dealer is going to deliver it and set it up for me. I have no plans of moving it in the near future.

 

[Republicoftexas69]

Yes I did consider number of these newer Class D amps but once I heard the new Accuphase P-4600 amp I bought it. It's slightly on the warm side of neutral, very detailed with a clean smooth high end and a wide and deep soundstage. It really is one of the most beautiful sounding amps I've heard. Not solid state sounding and not as warm as tubes.It's somewhere in between. You really have to hear it to appreciate it. It's on order and I hope to receive it by end of April. It does weigh 66 lbs but my dealer is going to deliver it and set it up for me. I have no plans of moving it in the near future.

Good for you. I hope you enjoy it. I have my X200 on Butcher Block amps stand with wheels. Makes it easy to move around and switch out in other systems in my house.