AHB2 Review - Kalman Rubinson, Stereophile
AHB2 - "A Real Breakthrough in Every Way"
"This compact, lightweight, cool-running, class-AB power amplifier is a real breakthrough in every way"
"When I unpacked the AHB2, I was impressed with its small size and weight: the non-rack-mount version is 11.04" wide by 3.84" high by 9.34" deep and weighs only 12.5 lbs. I was also impressed with a seriousness of design apparent in its features: The fully balanced AHB2 has, on its rear panel, only XLR jacks for signal input, plus a toggle switch that allows the user to select among three input-sensitivity levels. For output, the Benchmark amp offers a choice of traditional multiway connectors or a stereo pair of Neutrik NL4 sockets. A third Neutrik NL4 is provided for use when the amp is in bridged mode, which is selected with a second toggle switch."
"These features, along with the detailed manual and specs included with the amp, suggest that the AHB2's target market is the audio professional or the recording studio."
"... it was probably the AHB2's low noise level that revealed to me much more apparent low-level detail in already-familiar recordings. I qualify that statement with apparent because, after hearing the AHB2 uncover previously unheard subtle details, I found I could now hear them when I returned to my other amps. I suspect that, being newly informed of their existence, my ear/brain could more easily extract those details from the output provided all along by my other amplifiers. This made a much greater impression on me than any subjective awareness of a lower noise floor, per se."
"These surprising and delicious details were evident from the bass up through the midrange and extreme treble, which nonetheless remained silky and diaphanous."
"In addition to quantity of soundstage detail, the AHB2 was also "large" in power output. It was clear that this 100Wpc (into 8 ohms) stereo amp had all the power needed to drive with aplomb my Bowers & Wilkins 800 Diamond speakers to any reasonable level. At an SPL of 90dB, the B&Ws are of neither particularly high nor low efficiency, but JA has told us what makes them difficult to drive: ... there are current-hungry combinations of 4 ohms and –52° electrical phase angle at 62Hz and 5.3 ohms and –39° phase angle at 8.6kHz."
"That seemed to present no problem for the AHB2... I had to push the AHB2 to unreasonable and personally uncomfortable volume levels to get the least blink from one of its Clip LEDs"
"At first, I thought the AHB2 sounded less bright, and less full in the bass, than the other amps I had on hand, but after only a few days of listening I began to accept that it sounded more "right" than any of them. Now the treble wasn't so much un-bright as smoother and unaccented. The bass had all requisite extension and detail (see above), but seemed to be more naturally balanced with the rest of the audio band."
"As time passed and I listened more, I grew to love the AHB2's sound, and undertook the rewarding effort of listening through it to as many different recordings as I could. It was a great pleasure, as old friends, some already mentioned, smiled anew. Yes, I could hear the differences between the different amplifiers, and that's the point. This compact, lightweight, cool-running, class-AB power amp is a real breakthrough in every way."
- Kalman Rubinson, Stereophile
Also in Reviews
AHB2 Review - Constantine Soo, Dagogo
"The AHB2 bridgeable stereo amplifier ... was the topic of a recent discussion between American electrostatic panel speaker manufacturer Sound Lab’s president, Dr. Roger West, and me."
"In our discussion, he related his highly positive experience in driving even his largest, $55k Majestic 945 panels with the $7,000 pair of Benchmark Media AHB2 monoblocks, along with the $3,050 LA4 Preamplifier and factory XLR cables."
"Dr. West described the AHB2 as a class AB design using “feed-forward distortion reduction [thus removing] any possibility of pushing the margin of safety of a standard feedback loop, used in most amplifiers, into an unstable oscillatory mode.”"
"He further shared with me that “this is of most concern on powerful musical transients. The distortion of the amplifier in the balanced mode is astonishingly low even at just below the clipping level of 380 watts.”"
"The prospect of the AHB2’s specified distortion level of 0.00015% or lower when at full volume is comical at first glance, but upon actual audition the impact of the achievement is very audible from medium-high listening levels and upward."
"It was unlike any other sub-$20,000 amplifier I have auditioned."
"My audition of the Benchmark Media AHB2 amplifiers underscores the reason Dr. West is so taken by it, and confirms the design is best described as a watershed moment in the high-end audio industry."
- Constantine Soo, Dagogo
DAC3 Review - Jerry Del Colliano
"Benchmark is a stalwart brand in pro audio, but has carved out a very respectable niche in the audiophile world with their diminutive but powerful components."
"The audiophile world sometimes looks to the professional audio world for enlightenment, especially on the digital side of things, and Benchmark Media is one of the companies that we put high on a pedestal."
"They are hardcore digital engineers freezing their asses off in upstate New York as they come up with some pretty innovative ways to get your varied digital sources sounding as much like the master tape as possible. Thank you for your service, gentlemen."
"If you really want to hear what your music sounds like in today’s streaming-driven world, this might just be the DAC that you need to test out."
- Jerry Del Colliano, Future Audiophile
DAC3 & AHB2 - System Review, Trevor Butler, The-Ear.net
"I began with the DAC3 HGC and AHB2 powering the glorious Morel Avyra 633 three-way floorstanders."
"This pairing created a full-bodied sound which brought the recording to life."
"Notable from the off was the bass from the DAC3 HGC and AHB2."
"Wow! It was deep, tight and conveyed a real feeling that the electronics were in charge of the transducers."
"Involuntary foot-tapping confirmed the timing ability and the overall presentation was spot-on, the Benchmark electronics created a fluent sound across a vivid soundstage; performers evident both tonally and spatially in an easy-to-believe presentation that brought the performance close."
"The Benchmark’s ability to retrieve deep-down detail and display it so well across the soundstage, with accurate positioning and convincing layering, made for a glorious re-creation of the recordings."
"To my mind the AHB2 is an amplifier with no obvious characteristics of its own: the level of transparency is sublime."
"Above all, the improved transient response performance stood out in a presentation that was not only lively but incredibly fast and revealing. The attack and decay displayed was awesome and not something I expect at this price point."
"The Benchmark DAC3 HGC and AHB2 are cracking products, sonically superior to a lot that’s available and well priced."
"They are superbly designed and built to an extremely high standard."
- Trevor Butler, the-ear.net