As with every other Acoustic Research amplifier, the REF160M features KT150 valves (they can be seen through the chassis’ transparent faceplate) which have a claimed 3,000-hour life. Owners can monitor this claim thanks to the amplifier’s built-in valve usage meter.
The power supply stage uses a new transformer, and Audio Research engineers have created a new audio circuit with shorter signal paths and fewer components than in previous designs. It also features a circuit board (previously reserved for use in the brand’s preamplifiers) designed to lower the noise floor.
A proprietary auto-bias circuit that’s compatible with multiple valve types in addition to the KT150 works to maintain their bias while also adjusting for tube wear. And a cover with an integrated fan has been incorporated to cool the heat generated by four KT150 and 6H30 driver valves.
It’s also the first Audio Research amplifier switchable between ultralinear and triode modes (via a front panel button) - this allows owners to experiment with the different topologies in their system. It can offer 150 watts in ultralinear, and 75 watts in triode.
Unusually for Audio Research’s Reference-line amplifiers, the REF160M includes RCA inputs in addition to balanced XLRs inputs.
Two years in development, the brand’s latest monoblock power amplifier will be available in July (in black or silver finishes), priced £28,998 a pair.