"There’s a new actor in the high end audio amplification field – THX. The company is a technology spin-off from Lucasfilm, which originated the Star Wars movie series."
"THX has patented a novel amplifier design, THX AAA Technology(TM) and Benchmark Media Systems has turned it into a new power amplifier – AHB2. The design is called Achromatic Audio Amplifier. Achromatic may mean colorless or neutral or without modulation. The AHB2 is an attack on current amplifier design. It’s basically an AB amp with a class H power rail arrangement."
"A low power Class A correction amplifier ... runs in parallel with the regular AB amplifier ... and corrects ... non-linearity in the transition stage."
"The AHB2 is a class AB amp – but could easily be mistaken for a class D with its very compact dimensions. The small size is made possible by the compact switching power supply."
"The AHB2 has a resonant zero-voltage switching power supply. The switching is carried out at frequencies well above the audio band to reduce any audible artifacts from the power supply. Switching power supplies are much more efficient, and smaller, than linear transformer based supplies."
"The AHB2 power supply is regulated and very efficient in combination with the H Class rails. Benchmark claims that there is no sagging in internal voltage during high loads or when line voltage dips."
"The amplifier has a spectacular frequency response of 0.4 Hz to 200 kHz. This means that the AHB2 will amplify the high frequencies present on high res digital files."
"So is there a sound signature to the AHB2? Since THX calls it Achromatic we can assume that they were not aiming for a warm and sweet tubey sound – and this is not what it delivers. The sound is indeed neutral and exact without being sterile or clinical. Colorless? Not really. The amp will send through the sound palette of the source component and disc/file without stripping any color away."
"The Benchmark AHB2 is a solid foundation for an audio system. It is very quiet with extremely low distortion."
"The AHB2 is so good it will immediately expose weaknesses in your system. It requires a very good pre-amp ... which should output a balanced signal."
"Medals to everyone and a rebel princess to the AAA Technology inventor!"
LA4 - Receives Stereophile's Highest "Class A" Rating for Preamplifiers
"Benchmark's usual approach to design is to out-spec the competition, and so it is here. Like other Benchmark equipment he has tested, the affordable LA4 challenged the resolution of John Atkinson's test instruments, with'superb'channel separation,'extremely low noise, and virtually no power-supply-related spuriae.'"
"Benchmark's LA4 is the widest-bandwidth, widest-dynamic-range, lowest-noise, lowest-distortion preamplifier I have encountered."- John Atkinson
"In his listening room, Kalman Rubinson compared the LA4 to a cable—and couldn't hear any difference. He concludes,'the LA4 is probably the most transparent and revealing audio component I've ever used. It does not seem to leave any fingerprints on the sound.'"
"The DAC3 B is a stripped- down, lower-priced version of the DAC3 HGC, which omits the headphone amplifier, balanced and unbalanced analog inputs, volume, mute, and polarity controls."- Stereophile
"The DAC3 was all about depths, in several respects...I heard deeper into the music."
"All I can say is Wow!"
- John Atkinson
"In a Follow-Up, JCA wrote of using the Benchmark processor with the same company's AHB2 power amp—a combination of high source output voltage and modest amplifier gain that he describes as 'optimal for minimizing noise and distortion' —and reported hearing 'richer and more interesting' reproduction of very subtle details."