"This THX-888 amplifier is driven by a Benchmark line amplifier that features relay gain control, relay input selection and relay muting. The gain control has a whopping 256 steps in impressive 0.5 dB increments so that you can get exactly the volume that you want to hear!"
"You get a brilliant Touch Screen that in the end provides easy access to the plethora of features and settings on the amplifier. Everything from balance control, input level offset selection, personalized input names, screen dimming, remote control and function-locking are only a touch or two away with the intuitive user interface. Throw in an optional remote control, and you really get everything you’d ever need with a dedicated headphone amplifier."
"The HPA4 is 100% analog and is driven by an upstream D/A converter (DAC). The THX-888 can easily deliver high voltage into low-sensitivity high impedance headphones and it can conversely deliver high current into low impedance headphones. It easily drove all of the headphones I had on hand from my 300 ohm Sennheiser HD800S, to my 32 ohm Grado PS2000e and power hungry Abyss AB-1266 Phi TC orthomagnetic headphones. Heck, it was also dead silent on lower gain with all of my in-ear monitors too like the Grade GR10e IEMs. It literally is both a jack of all trades and master of all!"
"I plugged in the HD800S headphones and quickly selected Holly Cole’s “Collection Vol. 1”. This collection of classic Holly Cole songs is one of my favorite “go to” albums."
"The tonality of the piano in “Trust in Me” was simply “life-like”. The tonality and detail of Holly’s piano playing was as if I was transported to a jazz club with Holly paying in front of me. Her vocals were seductive, transparent and perfectly portrayed. The HPA4 amplifier offered an incredibly close look into this recording with the ability to mine out the smallest details that other amplifiers would seem to gloss over."
"Since the HPA4 arrived, I have rediscovered so many of my favorite works all over again with improved detail retrieval dynamics and transparency that it’s hard to pull myself away!"
"It drove my power hungry Abyss Phi TC headphones with complete authority, but it was still dead silent and nimble enough to amplify my easy to drive Focal Utopia headphones."
"Rarely have I come across such a wonderfully revealing amplifier that can drive many different types of headphones so darn well! The solid build construction and various controls make the $2,995 price tag seem a bit low based on the other headphone amplifiers in this market space."
- Peter Pialis, Headphone.guru
November 6, 2019
"Benchmark Media Systems’ LA4 preamplifier presented an utterly realistic reproduction of what was contained on each recording I played through it -- and weak recordings stood out more than usual. The LA4’s clean, analytical abilities are unmatched by any similarly priced preamplifier I know of. The LA4’s touchscreen brings it up to date with current user interfaces, and permits functions, such as balance control and muting at the device."
"If you want a preamp that editorializes, look elsewhere."
"If, like me, you value a high-resolution, totally neutral musical performance, add a Benchmark LA4 to your system, particularly if you already own a Benchmark DAC."
- Erich Wetzel, SoundStage! Hi-Fi
"You’ll have a tough time finding a cleaner, quieter, more transparent line amplifier and headphone amplifier anywhere, at any price. I found it to be a new reference. Once I heard it, I could not live without it, so I purchased the review sample. The HPA4 deserves my highest recommendation."
"The HPA4 is the latest product from Benchmark Media Systems, an upstate New York audio manufacturer. Benchmark calls it a headphone amplifier, but it’s really two products in one, combining the LA4 Line Amplifier introduced in 2018, with a headphone amplifier. It is also based on the same THX Achromatic Audio Amplifier technology used in Benchmark’s acclaimed AHB2 power amplifier."
- Gary Galo, Audioxpress.com
"Going into this test, based on measuring previous Benchmark products, I expected excellent performance. The benchmark HPA4 shattered even that high bar."
"It brings such a high performance to the table that leaves no doubt whatsoever about its transparency. No stone has been left unturned to optimize audio performance of this device. Even obscure measurements like ultrasonic interchannel phase shift is nailed."
"And then we have tons of power without messing with balanced cables and such. Plug in any headphone and you are in heaven."
"The preamp performance is even higher still, breaking and shattering any expectation one would have in a lab instrument let alone a consumer hi-fi."
"It goes without saying that the Benchmark HPA4 garners my strongest recommendation for a headphone amplifier and preamplifier. It doesn't get better than this folks."
- Amir Majidimehr, Audio Science Review