"The AHB2 easily outperforms the DIY Hypex NC400 I had tested before which used to be the best amp I had tested."
"THD+N versus output level looks far cleaner than anything I have tested before."
"Intermodulation distortion versus power level shows the same story of clean power."
"Usually when we test switching amplifiers we see all kind of "interesting" things in their outputs above hearing range. The AHB2 is a classic configuration albeit, with a switching power supply so all is well and clean here."
"Down 0.3 dB at 20 kHz. -3 dB down at 200 kHz!! Since this is not a switching amplifier, there is no filter there allowing the bandwidth to go to 200 kHz and beyond."
"We have 185 watts of power at incredibly low distortion of 0.00016%, besting the company specifications."
"500 watts into 4 ohm! Stunning 0.00026% distortion at 500 watts!!"
"As usual, I start with my 5 watt output test using 4 ohm load... I hope your jaw is on the floor just like mine was when I saw this picture emerge! 113 dB THD+N[at 5 W] in a power amplifier?Are you kidding me?"
"Look at the harmonic distortion. The worst case spike is below -130 dB! This is insanely good. Of course this type of SINAD (signal and noise ratio) crowns the Benchmark AHB2 as the best I have ever tested."
"Separating the noise from THD, we see that it is noise that we are measuring as THD+N, rather than distortion. Noise dominates (more benign than distortion)."
"There are a set of LEDs that show the status of the amplifier. They are driven by an FPGA (field programmable digital logic) that monitors all aspects of the amplifier and shuts down the unit if stressed. It did so very quickly and efficiently in my testing. Usually this is done with purely analog or maybe a small microprocessor. As such, the coverage of scenarios that could damage the amplifier is much less complete than using the approach Benchmark is using in AHB2."
"Bridged mode using same 4 ohm load ... you get 500 watts of stunningly clean power. Protection circuits shut the unit down after that, so it is quite safe to try. With a THD essentially matching the non-bridged mode, there is no reason to be afraid of trying this."
"... the FPGA protection mode kicks in and essentially shuts the amplifier down past the limit. You get absolutely distortion-less and noiseless performance until there is no more."
"There is a switch for selecting stereo or mono bridged output. The latter quadruples the amount of power available."
"In use the AHB2 stays very cool for a power amplifier when it is idling, outputting little power which was a nice surprise."
"Being a proper company of course the AHB2 comes with full set of regulatory/safety/emissions certifications which is super important with power amplifiers given the high voltages and currents running around in them."
"It goes without saying that the Benchmark AHB2 breaks new ground with respect to performance of power amplifiers."
"Using it, you can be assured that any distortion that you hear is from other sources (speaker, source, content, etc.). This is what I look for in high-end audio: absolutely the best performance so no second guessing is involved. You buy once, and you are happy forever!"
"All of this comes from a company that is a model of transparency with proper and accurate measurements of their products on their site. And importantly, volunteering to have that data shown to be correct by independent sources such as us."
"Needless to say, the Benchmark AHB2 gets my strongest recommendation."
- Amir Majidimehr (@amirm) - AudioScienceReview.com
"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
"It’s ... been a while since I have been this excited about an audio product."
"Audeze LCD-2C, Quad Era-1, Brainwavz Alara, Sennheiser HD650 ..."
"It’s the first time when I have heard the headphones mentioned above to their full potential. In the first minute my jaw dropped ..."
"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."
- Dan-Alexandru Gheorghe, HeadMania.org
"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