Benchmark Debuts High Dynamic-Range Amplifier
The Benchmark AHB2 amplifier, named in honor of the company's founder, Allen H. Burdick, who passed away just before the show, has a dynamic range claimed to approach 130dB, and outputs 100Wpc into 8 ohms, 170Wpc into 4 ohms and can be bridge to produce 340W into 8 ohms. THD+noise is said to be <108dB relative to full output at 1kHz. John Siau explained that the THX modules are operated in a mode that gave the lowest noise and distortion rather than the maximum efficiency I wrote about in 2012. A key to the low THD is the use of 0.01%-tolerance resistors at critical points in the circuit. A switching power supply is used, Siau feeling that this was optimal because all the power-supply spuriae will be out-of-band and therefore more readily filtered. It also means that the ubiquitous 60Hz magnetic interference from conventional supplies, which you can often find in my amplifier reviews and is picked up by ferrous parts in the circuit, is absent.
The AHB2 is made in the USA and will be available in December. It is shown below with the excellent Benchmark DAC2, which is scheduled to be reviewed in the February 2014 issue of the magazine. Price was still be decided; it is expected to be about $2500.