Building the AHB2 Power Amplifier - The Poor Audiophile Interviews John Siau
AHB2 - John Siau Explains what's Inside Benchmark's Unique Amplifier
In a recent interview by The Poor Audiophile, John Siau, Vice President of Benchmark Media Systems, explains some of the innovations in Benchmark's revolutionary AHB2 power amplifier.
"John is a long-time audiophile. In fact, it was his love of music and audio that originally inspired his interest in electronics and prompted him to pursue a degree in electrical engineering at Syracuse University."
"“Benchmark is not new to power amplifiers,” John told me. “For almost 30 years Benchmark sold the DA-101 audio distribution amplifiers for studio use. These were small 35 W card-mounted power amplifiers with a 150 kHz bandwidth, a 130 dB SNR and very low THD+N. These cards were designed to distribute line-level audio signals, but they were capable of driving speakers. Because of their outstanding performance, we often used these cards to drive monitors in our own listening room.”"
"That long experience with the DA-101 gave Benchmark some ideas for the next generation amplifier. As John mentioned, the team at Benchmark wanted to build an amplifier to bring out the potential performance of their DAC2 products. Benchmark wanted a high power, passively-cooled power amplifier that equaled or exceeded the performance of the DA-101. It was at that point that Benchmark knew that the current technology and existing topologies by themselves wouldn't be sufficient for their needs."
"“As we examined this task, it became clear that we would not reach our goals if we designed a conventional power amplifier,” John said. “We realized that we needed to look at some unique solutions. We were very focused on eliminating crossover distortion in the output stage because we felt that this was one of the most important factors in the sonic performance of the amplifier. We began experimenting with ...”"
Additional Reading:
The AHB2 - A Radical Approach to Audio Power Amplification - John Siau
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+