Unrestricted Dynamics: Reviewing the Benchmark LA4 Preamp and AHB2 Power Amp

Measurements speak for themselves at Benchmark Media Systems, a company that takes pride in the impeccable measured performance numbers of their products. Their engineers are confident that when you listen to music with the Benchmark LA4 preamp ($2,599) and the Benchmark AHB2 power amplifier ($2,999) you’ll immediately understand why measurements matter.

With roots in the broadcast and professional recording industries, Benchmark designs and engineers their equipment with a “measurements first” mentality. In mission-critical environments where a flat frequency response is not just expected but required, it’s imperative that the equipment doesn’t impart any of its own sonic character on the source material.

This accurate reproduction enables recording engineers and producers to showcase their creative talents. Benchmark aims to give you the same experience musicians and engineers have in their studios when they play a recording they have just mastered; pure sonic perfection.   

A Perfect Combination

One look at the LA4 preamp alongside the AHB2 power amp will tell you that they were made for each other. The synergy between the two products is obvious at first glance and it was confirmed during my first listen. The LA4 is a straightforward line-level preamp with four analog inputs, two analog outputs, and a summed mono output for a powered subwoofer. A relay stepped attenuator that uses gold precision-matched relays controls the volume level. From top to bottom, the design of the LA4 was meant to do one thing; preserve the sonic integrity of the material that passes through it.

The Benchmark AHB2 is more than a quiet amplifier – it’s a silent one. When powered on, it exudes no noise whatsoever from its chassis, nor is there any hiss from the connected speakers. You can literally put your ear an inch away from the tweeter, and all you will hear is complete silence. When listening, this subterranean noise floor allows your music to emerge from pure nothingness. You’ll be able to hear more from your favorite high-resolution recordings, and that’s a fact.

Rather than boring you with specifications that you can find in the user manuals, I’m going to focus on exactly what I experienced when I connected these two pieces of equipment together and took a close listen.

Listening with Benchmark

Prior to reviewing these Benchmark components, I had heard the company’s products powering some of my favorite-sounding rooms at several audio shows. Based on what I’d heard at these shows, I was eager to hear how this equipment could perform in my own listening room. With my expectations high and my excitement palpable, I put the LA4 and AHB2 into my system connected to the Triangle Comete EZ speakers (reviewed here) and an Aurender A100 Network Music Server (reviewed here) streaming the Tidal and Qobuz music services.

Two words immediately came to mind — unrestricted dynamics. As much as I thought I was mentally prepared for what I would hear, in reality, I wasn’t. I was shocked at the effortless dynamic swings that I heard from some of my favorite classical and jazz performances. I was also stunned by how certain sounds seemed to leap instantaneously out of the speakers and truly startle me. I had previously used the Comete EZ speakers with three other amplifiers, and I didn’t notice this explosive sensation. It was a genuine “you don’t know what you’re missing until you hear it” moment for me.

Design Goals and House Sound

I understood Benchmark’s design goals and house sound (or lack thereof) in my first ten minutes listening. Over the next several weeks that I spent listening with the LA4 and AHB2, I realized that in addition to the impeccable technical performance there was something else beneath the surface. It was the same unmistakable feeling that I also got inside the rooms using Benchmark products at audio shows.

Listening to the Benchmark gear in my own room, I felt an immediate and gratifying emotional connection to the music I was hearing. This unmistakable feeling was unique for me, and it was repeatable.

The LA4 and AHB2 tear down so many of the usual walls that come between the listener and the music. Without those walls, I was drawn fully and completely into what I was hearing. Since the preamp and amp didn’t have a sonic signature of their own, it meant that I could hear more of the source. The LA4 and AHB2’s specifications meet or exceed the measurements of most DACs. This allows all of the musical information upstream to reach the speakers.

As an audiophile, I strive to hear the soul, energy, and emotion contained within the music. My goal with this hobby is to enjoy that multi-faceted experience every time I listen. Pure transparency and unrestricted insight into my music is now affordable!

Hearing a Speaker’s Voice

I listened to several pairs of speakers with the Benchmark components, and I quickly realized that they allowed me to hear the speaker’s true voice. They showed both the strengths and the shortcomings without any coloration or influence. Here are some of the standout speaker pairings.

Triangle Comete EZ: This was one of my favorite pairings. I never had the desire to turn down the volume. The sound stayed crisp and composed even into 90+db levels, without a hint of harshness from the tweeters. They effortlessly scaled from big to small, and this made for a fun and dynamic listen, especially with well-recorded classical music.

PMC twenty.22: My reference monitor’s core strengths could truly shine with the LA4 and AHB2. Most notably, the PMC’s expansive and airy treble reproduction was prominently showcased. The jet-black background and spacious soundstage made it easy to hear every tiny detail. When distant sounds emerged from outside the speaker’s boundaries and wrapped around my head, it was spooky and ethereal.

Epos K1i: The Epos speakers showed off what’s possible when you pair up an inexpensive speaker with quality components upstream. The sound was three dimensional and not at all localized to the speakers. They had a precise center-locked image, with vocals coming from the area directly between the two speakers. The AHB2 kept a vice-like grip on the woofers and kicked out tight, satisfying bass. What stunning performance from a $400 pair of speakers!

Conclusion

Once I heard the Benchmark LA4 preamp and AHB2 power amplifier, I thought, “This could be my last preamp and amplifier purchase, ever.” As I lived with them and dove into my favorite music, I was continuously impressed by their flawless performance. Every time I listened to music, it was an introspective and emotional journey.

If you value transparency and accuracy, the LA4 and AHB2 will perform beyond your highest expectations. For $5,598, there may be no better way to get closer to the music.

Retail:
Benchmark LA4 preamp ($2,599)
Benchmark AHB2 power amplifier ($2,999)