"It’s ... been a while since I have been this excited about an audio product."
"I do have a good queue of products that deserve a review here, especially in the headphone department: Audeze LCD-2C, Quad Era-1, Brainwavz Alara. Hopefully I will get some time for them as well. However, in the meanwhile I am using them to test this wonderful wonderful headphone amplifier."
"I like the touchscreen and the implementation. It’s fast and easy to get used to."
"It’s the first time when I have heard the headphones mentioned above to their full potential. In the first minute my jaw dropped ..."
"This is the fastest and the most controlled bass I have ever heard. It goes deep, it’s organic when it needs to be, but it doesn’t linger at all. It’s controlled by an iron fist. The punch is really really fun and strong."
"The midrange is really pure and lively. The instruments and voices have vibrating, lively and pure textures."
"The treble is really extended, very detailed and sparkly. It doesn’t have any touch of brightness, but it does brighten up the place in a good way if you know what I mean."
"The level of detail is amazing on HPA4. I seem to discover other sounds in some songs that I did not notice before."
"The voices are incredibly pure and textured. Depending on the artist and the song, the voice can sound incredibly pure, stammeringly clean and extended, but also guttural/throaty in other cases."
"When you talk about natural sound, about emotion in this domain it usually means that the audio component adds some coloration that give a more natural tonality, more weight to the sound, more present voices, less harshness, etc. In this case the emotion comes from the purity of the sound from the fact that HPA4 completely removes itself from the system."
"From my perspective this is the best headphone amplifier I have ever heard. It’s no competition really."
"It’s not cheap, I can give you that. Is it worth it? That is up to each and every one of you, but if you really want the best amplifier out there, an end game amplifier…this is it."
"I ended up visiting this room more than any other room at the show. I couldn’t help myself; I had to keep coming back for more!"
- Drew Gagliano, TheAudioBeatnik.com
"The HPA4 combined with the Benchmark AHB2 power amplifier ranks as the quietest rig I've heard (or not heard). Even with the gain up to full with no signal, there is no hiss, hum, or buzz, even when I placed my ears within a in inch of the drivers on 89 dB sensitive loudspeakers."
"As a headphone amplifier, the HPA4 was first rate. Whether it was my most power-hungry headphones, which currently are the new Abyss Diana Phi, or my most sensitive IERs, such as the Empire Ears Phantoms, there was no added noise or lack of adequate gain."
"The Benchmark HPA4 exhibits virtually no noise, whether employed as a stereo preamp or headphone amplifier, and his highly transparent, with no audible colorations."
"If you are looking for a preamplifier/headphone amplifier that you can live with happily for a long time, you should consider the Benchmark HPA4 at the top of your must-audition list."
- Steven Stone, HomeTheaterReview.com
"Today, is a very special day for me, since I believe I am hearing the best overall performance out of my headphones."
"The distance performance-wise between HPA4 and my second-best headphone amp is Night and Day!"
"This headphone amplifier and line pre-amplifier receives my highest recommendation and scores the highest rank in my book."
"It spoiled me so much, that for the past 3 days I’m waking up at 5 A.M. so I can listen, tap my feet and head-bang just a little bit more. I for one, started saving for one, I’m sorry but I can’t go back to regular amps."
"Without a doubt Benchmark HPA4 is an end-game, top of the line headphone amp – it’s The One to rule them All."
- Sandu Vitalie, SoundNews.net