"The sonic results of all the time and effort spent refining this circuit and developing this design are nothing short of extraordinary! Bass is rendered with exceptional detail and speed, and brother can it go deep! In fact, I can't think of another amplifier (or pair of monos) I've experienced for under about $6000 that can do what the AHB2 can do with the bandwidth below 100 Hz. It has jaw dropping, chest-thumping impact while still being able to render remarkably accurate and refined pitch definition. In many ways, its bass performance reminded me of my time with the $65,000 WAVAC MD-805 Mk II monos, which rendered some of the most engaging bass I've yet heard."
"Midrange is simply captivating, rich in both musical resolve and harmonic texture. It affords an exceptionally well-balanced mixture of both tonal truth and emotional expression. Instrumental voices are provided the body and bloom needed to complete the "live" illusion, recording permitting, and are related with the proper texture and tonal color, if ever so slightly to the dryer side of natural."
"Treble is extended, airy, and resolute. Once again, I'm hard pressed to think of an amplifier for less than twice as much as the AHB2 that can even begin to compare, let alone match, this amps performance with the spectrum above 2.5 kHz. This extended and replete high frequency performance bestows a sense of ease and relaxed enchantment to well-recorded materials previously unheard of in this price point."
"One of the areas where the AHB2 really shines is in its ability to render the space between and the sense of both the space occupied by, and the interrelationships of instrumental positions and locations. Instruments and vocalists occupy an uncannily realistic sense of size and locale. I was left speechless more often than I cared to count by this engaging and enchanting ability."
"Benchmark's AHB2 amplifier is a truly breakthrough, innovative design."
- Greg Weaver, Enjoy the Music.com
"RMAF 2018 was really good, with significant numbers of attendees, and more new-product introductions than I remembered ever seeing there."
"Led by engineer John Siau and based in Syracuse, New York, Benchmark Media Systems has built a sterling reputation for making compact, well-engineered, moderately priced electronics that challenge the state of the art, both on the test bench and in the listening room."
"What I took notice of were the specifications: total harmonic distortion of less than 0.00006%, and a signal/noise ratio exceeding 135dB from 20Hz to 20kHz."
"If those claims are true, and there’s no reason to believe they aren’t -- Benchmark gear has always performed as specified on the test bench -- the LA4 should be about as transparent-sounding a line-stage as you can find at any price."
- Doug Schneider, SoundStage! Hi-Fi
"Benchmark describes its product as a 'reference Stereo Headphone Amplifier and Reference Line Amplifier with Relay Gain and Input Control', which should give you some idea of what's going on here, but only hints at the fact that this is actually two completely separate products packed into one relatively compact unit."
"The headphone section is powered by a power amp from THX, employing the same AAA (Achromatic Audio Amplifier) technology first used by the company in its AHB2."
"Benchmark's line amplifier uses relays for input selection, gain control and muting while four independent 256-step attenuators ... feed the the headphone ... and preamp outputs."
"As PM notes in his Lab Report, this design gives the HPA4 not only outstanding performance, but also rather impressive - to say the least - signal delivery."
"All of a track or two should do the trick, as whether with revealing headphones ... or used as a preamp, the HPA4 simply drops jaws with the sheer impact, openness and vivacity of the way it plays music."
"It was one of those real 'performer in the room' experiences and I was instantly transported back to the time I spent monitoring the recording as it was being made ..."
- Andrew Everard, Hi-Fi News, November 2018