"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."
"Unlike most headphone amps able to do double duty as a preamp, this one doesn't split its output ... but actually has discrete amplifier sections for the two functions."
"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."
"I played a new Channel Classics recording, pianist Anna Fedorova's Four Fantasies [CCS 41318; DSD 256], and was instantly struck by the way it sprang to life, with every element of the playing, and the size of the Steinway in a credible concert-hall acoustic, readily on display."
"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 in the Eindhoven Muziekgebouw back in July."
"The HPA4 can certainly rock out, it prodigious capability when it comes to output levels meaning it can five as much as your phones can take."
"Its beauty is that it sets no limits on your system: any failings audible will need to be looked for elsewhere."
"I'm asking because clearly Benchmark is a highly regarded company here, and plenty of ASR members own Benchmark amplification/DACs. We know they are top of the heap in terms of measured performance, outdoing plenty of the competition in terms of typical distortion measurements."
- @MattHooper, AudioScienceReview.com
AHB2, LA4, DAC3
Subtle aesthetics? Check.
Unobtrusive size? Check.
Solid build? Check.
Made in America? Check.
Best in class? Check.
Superior performance proven by Amir? Check.
Superior customer service? Check (and not just in audio world; best customer service I have experienced from any company, anywhere, ever).
Expensive? For me, yes. Limit of my budget, but buy once cry once.
"The afternoon before the start of the show I ran into John Siau of Benchmark Media Systems. He says to me quietly, “make sure you stop in our room, we have a surprise!” With curiosity suitably piqued, Co-Editor Jim Clements and I paid a visit ..."
"The results were pretty astonishing. A stable, enveloping stereo image that was devoid of any distortion whatsoever."
- Carlo Lo Raso, Secrets of Home Theater and High Fidelity
"Sound was extremely well-integrated and controlled, and the bass memorable."
"The Note received signal through the introductory version of the company's Liquid Cables. Each cable contains 27,000 wires. The company's introductory Elephant memory player joined Benchmark Media's AHB2 power amps, DAC3 B D/A processor, and interconnects."
"With the aid of a forthcoming DEQX HDP4 processor that's due in the fall, the system sounded super on a 16/44.1 file of the famed rendition of Copland's Fanfare for the Common Man, recorded by Eiji Oue and the Minnesota Orchestra for Reference Recordings."