"The AHB2 makes use of THX Corporation's Achromatic Audio Amplifier (AAA) technology, in which a low-power feed-forward amplifier drives a low-bias class-AB output section, the latter energized by a system of class-H power-supply rails that deliver power in response to demand - resulting in an extremely efficient amplifier capable of robust power output."
"More apparent low-level detail" - KR
"In his listening tests, Kalman Rubinson discovered 'much more apparent low-level detail in already-familiar recordings' - a characteristic he credited to the Benchmark's evident noiselessness - and a tonal balance that 'sounded more right' than any of the other amps on hand."
"An extraordinary amplifier" - JA
In measuring the AHB2 and attempting to confirm its specified very high signal/noise ratio, John Atkinson observed nonlinearities in his testing equipment that 'Haven't affected the measured performance of other amplifiers I've tested, but they were detectable with the AHB2's very low intrinsic distortion and noise.' His conclusion: 'an extraordinary amplifier.'"
"Kalman Rubinson's last word: 'bargain'"
Stereophile rates recommended components by placing them in one of 6 classes; A, B, C, D, E, and K. Of these, the highest rating is "Class A". Benchmark shares this small and elite class with amplifiers costing 10 to 20 times more than the AHB2.
"Best attainable sound for a component of is kind, almost without practical considerations; 'the least musical compromise.' A Class A system is one for which you don't have to make a leap of faith to believe that you're hearing the real thing."
Jim Austin wrote, "The DAC3 was all about depths, in several respects . . . I heard deeper into the music."
The concise conclusion to John Atkinson's Measurements sidebar: "All I can say is 'Wow!'"
In a Follow-Up, Jim Austin wrote of using the Benchmark processor with the same company's AHB2 power amp—a combination of high source output voltage and modest amplifier gain that he describes as "optimal for minimizing noise and distortion"—and reported hearing "richer and more interesting" reproduction of very subtle details.
- Stereophile Magazine
"The benchmark combination offers a full range of equipment that can hardly be topped, leaves nothing to be desired in terms of sound, and meets professional requirements without any ifs or buts."
"The HPA4 has the HIFIMan one hundred percent under control, eliciting neutral timbres, tons of spatial information and crisp dynamics."
"I connected everything the household had to offer in terms of speakers - Spendor S3 / 5, Ayon Seagull / c, Quad ESL57. It goes without saying that the American coped with the dynamic boxes with ease. But even the quads, which have some meanness on the part of their impedance, did not pose a challenge for the amp."
"There are many things that come into play when putting together a hi-fi system, one of which is synergy."
"After the arrival of the Benchmark Media Systems AHB2, I immediately thought of the matching HPA4 that colleagues Jaap and Yung were very pleased with."
"The key question, of course, was whether the HPA4 would really provide an audible improvement."
"Well you bet! The synergy between preamp and power amplifier is nothing short of magical, not to mention the DAC3 B that I got from importer Helios for the occasion."
"Not only a few curtains disappear, the whole window is gone."
- Geoffrey Vanhouwaert, Alpha-Audio