Benchmark AHB2 or Class D (GaN FET)

The Benchmark AHB2 seems to be a different twist on linear Class AB amplifier design.  This amp uses a different approach to distortion cancellation that gets around some of the problems of using large amounts of negative feedback.  It uses a THX patented technology (under license) called AAA.  This amp has been around for several years. It gets rave reviews, so I am surprised that the technology is not in more widespread use.

I am interested in why this approach is not more widely used.

Also, how would this amplifier compare to the newest Class D technology, which uses GaN FETs and much higher switching frequencies.  (GaN Class D amplifiers which are price-competitive with the AHB2 are the LSA Voyager and Peachtree).  

At a higher price point would be Atma-Sphere Class D monoblocks and the AGD Tempo.

I would appreciate hearing the forum members' opinions on the AHB2 technology vs the latest Class D amps.




Gold Note PA-10 GaN FET class A/D power amplifiers and they are truly balanced and are bridgeable. Reviews are all positive and I have auditioned these with both tube and SS preamplifiers and they are Italian marvels. Outstanding value and sound. 


I have owned the AHB2 stereo and monos. I love the crystal-clear sound of the AHB2. It is actually my favorite sounding amp. However, I sold them to get am amp with much more power, CODA #16. Overall, I like the CODA #16 better.

Here is a great description of how the AHB2 sounds. Totally agree with this post.

(2) Review and Measurements of Benchmark AHB2 Amp | Page 5 | Audio Science Review (ASR) Forum

Currently, I also own a modded Peachtree GAN1 "amp". The mods took it to spectacular levels. However, it is a PIA to use. So, I am going to use the GAN1 for headphones and get another amp for the Yamaha NS5000 speakers. The GAN1 is currently driving the NS5000 and it sounds very good. Just a PIA to use.

If you do not have a very hard to drive speaker, then you may like the AHB2. I am thinking about it for the NS5000.


I owned an AHB2 for about 7 months and I just sold it about a month ago. I used it for headphones and I tried it on my speakers as well.  It was ok but not my cup of tea so that was the reason I sold it.  It was quiet and it provided a black background but it was never engaging.  I tried it with 2 tube preamps, McIntosh C2600 and Linear Tube Audio reference Microzotl preamp, and one solid state preamp, Holo Serene KTE.  For headphones, I like my 4 dedicated headphone amps better (Woo WA23, Auris Nirvana, Enleum 23R and Holo Bliss KTE).  For my Klipsch Cornwall IV speakers, I like my First Watt F7 much better.  I didn't try the AHB2 on my other speakers, Harbeth M40.1 or Sterling Broadcast LS3/6.

If I were in the market for a 100w/Ch solid state amp, I would strongly consider the Atmasphere class D mono blocks that I heard at Axpona.   I've never liked class D amps in the past but those mono blocks sounded great on the Fritz speakers. 

Because an amp uses GaNfets does not mean it is the cat's meow.  The Purifi module and now the sonically better and more powerful HIGH POWERED Purifi modules sound really great......and also Hypex has released its Nilai amps and preamps (available as DIY or assembled).  This is Hypex's best sounding module.....even better than the just released NCX500.  And these Purifi amps and Nilai amps are under $2K for a stereo amp ($1379 for a Nilai stereo amp kit....super easy to build) and just over 2K for mono blocks (over 200 watts a channel into 8 ohms).....less than half of Atmasphere.  And you can have them modded, as well, for even better sound.  Check out VTV Audio.....they sell them both.....along with the all digital amp:....the VTV D300 (300 watts a channel0 stereo amp....what I am using right now).  Orchard Audio also makes great class D amps that do use Gan fets....starting at $2650 for a basic stereo amp....

I don’t see any mention of GaNfets being used in the Gold Note P10.......can you show me where it states that? In the ASR review it mentions Mosfets.

Here is some info on the latest Hypex designs: