"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 don't think it is sterile sounding at all ... it is very neutral."
"In the studio, neutral, flat and detailed are on the top of my list."
"The HPA4 is speeding up my work, helping me make better decisions."
- Ken Jacobsen, Ken Jacobsen Music
"It has already been noted in previous reviews that the professional market often offers products that may also be of interest to the 'ordinary' consumer. In Japan in particular, home systems often consist of a mix of consumer equipment and (vintage) professional items."
"Benchmark was founded in 1983 and started building professional audio equipment."
"The goal, from the outset, is to build sound-transparent equipment of the highest quality. The employees are musicians, audiophiles and audio technicians. So sound quality is top notch."
"The HPA4 and LA4 are preamplifiers and largely identical. The HPA4 also has a built-in headphone amplifier."
"The Benchmark HPA4 and LA4 preamps deliver a very high quality neutral and transparent signal."
"Developed from a professional focus on sound reproduction, they bring the essence of the recording closer to the listener."
- Ruud Jonker, FWD Magazine, fwd.nl
"Before I dig into the sound of the LA4 it is important to know that it employs a wide bandwidth design. The LA4’s bandwidth is specified at 0.2 Hz to 500 kHz."
"Most of the wide bandwidth designs I have heard exhibit ... a purity in tone with superb timing and speed ... the LA4 proved to be no exception."
"The Benchmark LA4 yielded a change that was quickly apparent in several areas. Notably were; bass, upper midrange, treble, low-level listening, and the ability to distinguish the colorations of other components that were contributing to my overall sound."
"Acoustic guitar, piano, and harmonica among many other instruments are presented with speed, clarity, and coherency that made them sound more “present” in the room and less like a recording."
"The Benchmark LA4 is simply the most transparent, least colored, and most revealing component I have had in my system to date. I look forward to it joining my stable of reference components."
- Ken Redmond, The Audio Beatnik