"I believe it is the purest sounding and lowest noise amplifier in my experience."
"Is the AHB2 the “perfect amplifier?” The truth is that it could be when paired synergistically with certain components and speakers."
"What is perhaps most impressive about the AHB2 is its very natural presentation of brass horns, piano and percussion in general."
"The Benchmark AHB2 is a powerful and efficient amplifier with prodigious low levels of noise and distortion. The fact that it is also very musical and non-fatiguing, courtesy of THX’s patented AAA™ technology, is the icing on the cake. Benchmark Media and THX have a lot to be proud of for the development and implementation of the new technology the AHB2 represents."
"The AHB2 provides deep, impactful, and articulate bass, a very musical and transparent midrange, and ultra-clean high frequency reproduction."
"In addition to the AHB2’s impressive bass performance, the midrange sounds extremely pure and clear, not only on vocals, but on many other midrange instruments such as brass horns, woodwinds, piano, and strings of all kinds. But it isn’t merely the stunning clarity of the Benchmark amp that lets one know it’s very special, it is the musicality and authenticity one hears from his or her favorite recordings."
"I very much enjoyed my time evaluating the Benchmark AHB2 amplifier and can heartily recommend it to those seeking one of the lowest distortion and lowest noise amplifiers on the planet—one that is very musically transparent and easy on the ears to boot."
- Frank Alles, Stereo Times
"It’s ... been a while since I have been this excited about an audio product."
"Audeze LCD-2C, Quad Era-1, Brainwavz Alara, Sennheiser HD650 ..."
"It’s the first time when I have heard the headphones mentioned above to their full potential. In the first minute my jaw dropped ..."
"From my perspective this is the best headphone amplifier I have ever heard. It’s no competition really."
"It’s not cheap, I can give you that. Is it worth it? That is up to each and every one of you, but if you really want the best amplifier out there, an end game amplifier…this is it."
- Dan-Alexandru Gheorghe, HeadMania.org
"The HPA4 combined with the Benchmark AHB2 power amplifier ranks as the quietest rig I've heard (or not heard). Even with the gain up to full with no signal, there is no hiss, hum, or buzz, even when I placed my ears within a in inch of the drivers on 89 dB sensitive loudspeakers."
"As a headphone amplifier, the HPA4 was first rate. Whether it was my most power-hungry headphones, which currently are the new Abyss Diana Phi, or my most sensitive IERs, such as the Empire Ears Phantoms, there was no added noise or lack of adequate gain."
"The Benchmark HPA4 exhibits virtually no noise, whether employed as a stereo preamp or headphone amplifier, and his highly transparent, with no audible colorations."
"If you are looking for a preamplifier/headphone amplifier that you can live with happily for a long time, you should consider the Benchmark HPA4 at the top of your must-audition list."
- Steven Stone, HomeTheaterReview.com
"Today, is a very special day for me, since I believe I am hearing the best overall performance out of my headphones."
"The distance performance-wise between HPA4 and my second-best headphone amp is Night and Day!"
"This headphone amplifier and line pre-amplifier receives my highest recommendation and scores the highest rank in my book."
"It spoiled me so much, that for the past 3 days I’m waking up at 5 A.M. so I can listen, tap my feet and head-bang just a little bit more. I for one, started saving for one, I’m sorry but I can’t go back to regular amps."
"Without a doubt Benchmark HPA4 is an end-game, top of the line headphone amp – it’s The One to rule them All."
- Sandu Vitalie, SoundNews.net