"This is a review and detailed measurements of the Benchmark HPA4 headphone amplifier and preamplifier. The company was kind enough to loan me one for testing. It is a collaboration between Benchmark and THX to implement the "888" standard."
"Are your socks blown off as mine are? Second harmonic distortion is at an incredible -140 dB. That is insanely good. THD meter is running out of zeros to describe it as a percent!"
"Once we get to 1 volt, the IMD measurement floors at the same level as my analyzer. We cannot measure how good it is!"
"Crosstalk performance is beyond imagination: Worst case crosstalk is -123 dB at 20 kHz!!!"
"Perfect frequency response to 200 kHz!!! - It doesn't get more perfect than this."
"Perfect phase match to 200 kHz!!!"
"Using the 1/4 inch headphone jack ... distortion is ever so slightly above pre-amp mode but it is still exceptionally low at -138 to -140 dB. This is by far class leading as the THX AAA 789 could "only" muster -130 dB."
"The full dynamic range, 133 dB, is absolutely superb and bests the THX AAA 789's measurements by whopping 10 dB."
"Lower THD+N than THX 789 at all power levels. 445 milliwatts of power (exceptional). Distortion at max power = -113 dB!! Most important thing is the power level. The HPA4 sails past the THX AAA 789, providing almost half a watt of output or three times more."
"Lower THD+N than Massdrop THX. Max power = 3.5 watts (superb). Distortion = -112 dB at full power."
"Across incredible range of 110 dB of attenuation, you have perfect channel matching. There is a balance control anyway if you did need to adjust anything."
"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 (@Amirm), Audio Science Review
"There are many things that come into play when putting together a hi-fi system, one of which is synergy."
"After the arrival of the Benchmark Media Systems AHB2, I immediately thought of the matching HPA4 that colleagues Jaap and Yung were very pleased with."
"The key question, of course, was whether the HPA4 would really provide an audible improvement."
"Well you bet! The synergy between preamp and power amplifier is nothing short of magical, not to mention the DAC3 B that I got from importer Helios for the occasion."
"Not only a few curtains disappear, the whole window is gone."
- Geoffrey Vanhouwaert, Alpha-Audio
"The Benchmark AHB2 is a very fine sounding, easy to live with, zero-maintenance power amplifier that has enough power for most systems. If more power is needed, two amplifiers configured for mono can provide it. The decision to purchase the review sample and make the Benchmark AHB2 a new, long term reference took over a month of listening and comparisons."
"The outstanding musicality of the Benchmark AHB2 takes some time to convince the listener of its wholly musical presentation. This subtle excellence assures long term satisfaction."
-10 Audio, Perfect 10 Award
Alpha-Audio.net tested 10 DACs side-by-side. Only one received the "Alpha-Audio Approved" award. That DAC was the Benchmark DAC3.
"Are you looking for the best DAC (d/a converter) in the price range from 1500 euro to 2500 euro? That’s great! Because we’ve put ten beauties side by side. And we tested it live on camera for you."
"It was incredibly instructive to put so many converters side by side. We clearly hear differences - and the viewers could as well."
"One of the models we all agreed on is the benchmark DAC3. This is a delicious musical product. Virtually no coloring, nice stereo image and plenty of inputs."
DAC3 - Alpha-Audio Approved!