HPA4 - Lab Report - Paul Miller, Hi-Fi News

October 09, 2018

HPA4 - Lab Report - Paul Miller, Hi-Fi News

Benchmark HPA4 - Internal View

"Here's a brand that's aptly named - its products providing a 'benchmark' technical performance. The HPA4 is no exception with its relay-switched stepwise volume attenuator calibrated in 0.5 dB steps over a 'useable' 105 dB range."

"Distortion and noise are vanishingly low."

"The frequency response is ruler flat (+/- 0.01) dB from 1 Hz - 100 kHz."

"The[line output] source impedance is a sensible 30 Ohms and the maximum output a huge 22 V."

"Via the headphone amp, the maximum voltage is 11.2 V and ... the maximum power output is a substantial 4.4W/25ohm and 7.7W/8ohm."

"So, not only will the HPA4 drive the toughest headphone loads but its ... insignificant -102 dBV (8uV) residual noise also ensures exceptionally quiet backgrounds when listening with the most sensitive headphones/earbuds."

"Distortion is broadly unaffected by loading."

"The source impedance is a low <0.6 Ohms up to 10 kHz, increasing to 0.78 Ohms at 20 kHz."

- Paul Miller, Hi-Fi News

Read the entire article from the November 2018 issue →



Also in Reviews

AHB2 - Lab Report - Amirm,  Audio Science Review
AHB2 - Lab Report - Amirm, Audio Science Review

May 30, 2019

"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."

Signal to Noise Ratio:

(unweighted, 22.5 kHz BW)

  • Ch1: 130.286 dB

  • Ch2: 130.180 dB

Frequency Response:

  • -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."

Stereo Power into 4 Ohms:

"We have 185 watts of power at incredibly low distortion of 0.00016%, besting the company specifications."

Bridged Mono Power into 4 Ohms:

"500 watts into 4 ohm! Stunning 0.00026% distortion at 500 watts!!"

"It goes without saying that the Benchmark AHB2 breaks new ground ... gets my strongest recommendation."

- Amir Majidimehr - AudioScienceReview.com

Read More
AHB2 and HPA4 Review - Ulrike Schwarz, Anderson Audio NY
AHB2 and HPA4 Review - Ulrike Schwarz, Anderson Audio NY

May 29, 2019

"The AHB2 power amps ... are fantastic."

"I use them as mono blocks due to my power hungry speakers."

"I hear clarity, precision and an openness in the treble that I haven't heard in my speakers before."

"The HPA4 line and headphone preamp and the power amps are made for each other..."

- Ulrike Schwarz, Anderson Audio NY

Read More
AHB2 & Marting Logan ESL 11A - Axpona 2019 - The Audio Beatnik
AHB2 & Marting Logan ESL 11A - Axpona 2019 - The Audio Beatnik

May 29, 2019

197 Rooms - Benchmark Room makes a "top 3" list

"The effortless and free-flowing nature of the Martin Logans paired up nicely with the transparent AHB2 amplifiers."

"The tonality and realism of the instruments were spectacular. An alto saxophone sounded as if it was in the room with me, and the pitch and timbre of both male and female vocals were absolutely spot-on. It was clear that nothing in this system was getting in the way of the music."

"Their room had a remarkable degree of transparency that made every listener feel closer to the music."

- Drew Gagliano, TheAudioBeatnik.com

Read More