Review: Benchmark AHB2 Power Amplifier

It came as the perfect pairing for the matching DAC3 digital converter and pre. A full loom of Benchmark cabling with correlating connectors even accompanied the review sample. Everything stocked, locked and loaded in proper working order as a complete package ready for any pair of speakers.

The AHB2 power amp is usually demo’d with a pair of the Benchmark’s own stand mount SMS1, so in the lab we went straight to the TAD Micro-Evolution One’s in for review from MoFi Distribution. Linked up with the included Benchmark brand wiring, the entire package felt physically sturdy and very well connected, even compared to the wide array of other cable companies that have made their way through AH HQ. The big play from Benchmark has always been more from the professional monitoring side than audiophile roots, but the company has managed to straddle the chasm that spreads between production and consumption with tight packages and well-measuring gear. Even as forums claims of “one of the best measuring DACs out right now” trickle around the internet for the DAC3, so does John Atkinson’s bench test for the AHB2 with high marks for both clarity and dynamic range – pushing the limits of the measuring capabilities of his Audio Precision system. Indeed, real world playback corresponded in turn with both these assumptions. Of course power concerns tug closely to the feature set of any amplifier so prospective buyers can rest assured for most non-extreme systems at 100W into 8 ohms in stereo mode and 380W in bridged mono. For those extreme conisuires, consider two units a capable contender. Website claims even tout capablities to handle stereo loads as low as 1.4 to full output.

The topology and overall design hopes to touch on a new direction for more traditional audiophile ways. A “bipolar class AB output stage” is married with class H (hence “AHB2”) and some THX-AAA Technology (Achromatic Audio Amplifier) and makes claims of superior performance to the high-end fav, class A. In any case, heat dissipation didn’t run amuck with the AHB2 and its small form factor felt distinctly class D, even as the sound quality securely set it self apart from some of the more negativity stereotypes of the more entry-level class of amplification. Indeed the temperature coming off the dual-sided heat sinks wasn’t unbearable and the compact footprint is only extended further than the DAC3 via those metal dissipators. Its a tick more practical than full-size casework, and harkens back to some of Wyred4Sound’s mono elaborations. The faceplate design does allow for a longer rack-mounted version for those interested. The back panel offers up a whole host of connections including balanced in, standard speaker binding posts, NL2 2-pole speaker connections, 12v trigger but no SE inputs – just something to keep in mind in case your coming from that space on your pre. There is also a 3-step sensitivity switch and one toggle for mono mode.

While I try not to spend too much time in the comment section of any site or social media network, one angry Facebook patron recently decided to convey his opinion that any review of an amplifier is a complete farse, quoting the descriptor of “silky highs” as the crux for his disbelief. I understand his perspective, amp reviews are not the easiest to communicate. So while I intentionally shy away from silky anythings in this review, let me start with the most identifiable positive trait (there are many) of the AHB2, and that is low end control. Tightness, accuracy and punch. The polar opposite of saggy, cloudy and mushy. This is what you can expect from the amplifier. The extra pushy power rating doesn’t hurt matters, but a whimpy low end was never encountered with any speaker pairing we had on hand. The same cannot be said for our in-house Rega Brio-R Integrated, which loses a bit control with harder-to-drive transducers. The supremely firm bedrock laid in that region made for good listening with the 3-way TADs, even moreso considering the total size of each component. Treble regions are extremely acute. The stellar imaging of the ME1 was only further enhanced by the AHB2 treatment, allowing for razor sharp focus with no hard edge or unnatural splash. Overall the influence is much like the DAC3, transparent and analytical. This combination fared well in balance with Zu’s full-range budget Omen (although not quite as resolving) and doubled down with punch and precision with the 3-way Elac Uni-Fi bookshelf as well.

Adding the tube-based Woo WA33 acting as a pre amp brought along some additional timbral density, and hinted at perhaps a relevant combination for others who fancy more richness over straight one-for-one digital transparency. The sound of the amplifier is true to source and one that takes many queues from the production world of balance and monitoring. There isn’t much (if anything) added into the sound, so those with heavy preferences might salt to taste moreso than your audiophile-targeted component.

The AHB2 has power in spades, especially with two units running in mono mode. The low end tightness and thrust is just where it should be, and pass though information is the name of the game. A single amp in stereo will suffice for most normal situations, and was in full control of all sonic responsibilities with every pair of loudspeakers we threw at it. The Benchmark amp is another great solution for hifi that doesn’t take up too much space on the rack, and complements the company’s own DAC3 well, for an audiophile sandwich that will rock the house (or sooth the baby to sleep).

More info: https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier