AHB2 Technical Analysis - Robert E. Green, The Absolute Sound
AHB2 - "A Technical Tour de Force Without any Question"
"The Benchmark amplifier is quieter than any other amplifier I am aware of."
"It has noise of around 110 dB down relative to 1 watt, and since it has 100 watts of power, the signal-to-noise ratio that is relevant to resolution is around 130 dB. Not quite enough for 24 bits in theory—130 dB corresponds to 21.5 bits—but in practice enough for anything."
"Each bit gives one 6.02dB of dynamic range. So 130dB of dynamic range corresponds to between 21 and 22 bits. This means that the amplifier is very unlikely to be a limiting factor in terms of signal-to-noise ratio—or equivalently, resolution."
"Do you hear noise from your speakers when there is no signal present? If not, making your amplifier quieter will not make any difference."
"But if you have for instance very high sensitivity speakers so that one watt is going to correspond to a lot of sound (e.g., over 100 dB for Klipschorns), and you are not going to go beyond that one watt very often, then the quietness of the Benchmark, of noise being 110 dB down from one watt, may come into play more emphatically."
"Most amplifier manufacturers give noise down from full output level, typically something like 110 dB down. If an amp has 100 watts, that is 20 dB above one watt, then the amount by which noise is down from one watt is maybe only 90 dB. So with a speaker with 100 dB sensitivity will put out 10 dB of noise. K-horns usually hiss a little at you when they are not playing if they are fastened up to a turned-on amplifier."
"In any case, no matter what kind of speakers you have, you are going to find the Benchmark dead quiet."
"The Benchmark also has extremely low distortion—among the lowest around and surely far below known thresholds."
"The Benchmark can be used in bridged mode, to give 400 watts into 8 ohms (actually 380W is specified). That ought to be enough for most applications except in extremely large rooms."
"The Benchmark AHB2 amplifier is a technical tour de force without any question."
- Robert E. Green, The Absolute Sound, April 2016
Also in Reviews
Benchmark System Review - Ricky Dasler, Living Sound, New Zealand
"With over 40 years as an audiophile and more than half those years as a hi-fi retailer, I feel I’ve finally put together a stereo that ticks all my sonic boxes. Those being in order of priority, dynamics, scale, tonal accuracy, fatigue free resolution and soundstage."
"For the last 25 years I’ve been fortunate to have a dedicated listening room. I use acoustic treatments from Real Traps, Vicoustic and Primeacoustic."
"My Benchmark components consist of the DAC3 B (connected to a Naim NDS streamer), LA4 line amplifier and two AHB2 power amplifiers run in bridged mono mode. All cables are Benchmark too."
"The Benchmark gear in my system has brought what I have wanted in my list of sonic priorities as listed above and then some. They have delivered way beyond what I thought could be possible in my system in my room."
"I’m delighted and stunned daily as my vast music collection comes to life on a whole new level."
- Ricky Dasler, Living Sound, Nelson New Zealand.
Benchmark Converters at Abbey Road - Geoff Pesche
"What are the Latest Advancements in Mastering?"
"Geoff Pesche weighs in on how the mastering team at Abbey Road Studios achieve first-class results." - Mix with the Masters
"The biggest sonic improvement in mastering in the last 5 or 6 years is D/A and A/D converters and that's very very important - what you have at the front and the back of the chain."
"We use fairly new Benchmark converters front and back."
"Abbey Road like a uniformity between the rooms so all of the rooms have the same A/D and D/A conversion."
- Geoff Pesche, Mastering Engineer, Abbey Road Studios
DAC3 Review - Alan Sircom, hi-fi+
"A Damn Good, No-Frills Digital Converter"
"Benchmark Media Systems’ no-nonsense approach to all things audio is rare today."
"Uniformly Good"
"This is a DAC that’s uniformly good at everything. It resolves well, has good imaging properties."
"It makes a balanced, honest sound that allows you to sit and listen to music for hours. That is what makes Benchmark’s products consistently popular with audio engineers. You don’t want ‘bright’ if you sit at a mixing desk 10 hours a day. "
"Leave No Trace"
"It also has the latest version of Benchmark’s jitter attenuation system (UltraLock3) and doubles down on the digital demon with its multi-mode asynchronous USB system."
"Benchmark also uses the distortion compensation facilities built into the ESS chip to reduce second and third order distortion."
"The net result is a DAC that delivers lower distortion, lower noise, less passband ripple, faster signal switching and locking onto signals and a more linear frequency response."
"The Benchmark Media Systems DAC3 B is very much in the ‘leave no trace’ school of good audio."
- Alan Sircom, hi-fi+