The Reference 80S stereo amplifier continues Audio Research’s latest design effort in creating a vacuum-tube amplifier that not only redefines ultimate music reproduction, but does it in an incredibly beautiful package.

The 80S was created with as much spirited authority as we can pack into a compact circuit with 2 KT150 tubes per channel for music lovers who want Reference-level performance at the lowest possible barrier to entry.

Like every Reference amplifier before it, the 80S is a fully-balanced differential design, delivering the highest performance and lowest distortion. A four-layer circuit board is used to provide a separate ground plane, better circuit layout, and fewer noise-inducing point-to-point connections.

Music is projected against a quiet, jet-black background—like looking at the stars out in the country, removed from light pollution. It is magical and enveloping. The finest details are heard, with rich harmonics, incisive bass, and full dynamic contrasts, showcased with the ambience of the original acoustic space.

Outwardly, the 80S shares the same dimensions as the 160M. A single shallow whisper fan is built into the bottom plate. Flexibility is built-in, too, with XLR and SE inputs, 4-8-16 ohm output taps, 12V input and output triggers, RS232 input, tube hour meter, switchable fan speeds, and defeatable auto-off function.

The feature set is the same as the 160S, including a proprietary auto-bias circuit that adjusts for not only tube age, but for powerline voltage swings. There is fusing of the output tubes for safety and stability, single-ended and balanced inputs for flexibility, switchable Triode/Pentode operation – distinguished from the Triode/Ultralinear modes in the 160 models – to accommodate loudspeakers and personal preference, output tube monitoring, and inclusion of an hour meter. This is a tube amplifier that does not require fiddling and is meant to be enjoyed. The built-in 12V trigger turns the 80S on or off when connected to a modern preamp.

Built by hand, from the ground-up in our Maple Grove, Minnesota facility, the 80S can fool you into feeling you are in the presence of the musical performance. Whatever your reference speakers may be, whether they are from Wilson, Magnepan, Vandersteen, Focal, Sonus faber, B&W, or countless others: the Reference 80S will elevate their performance to a new plateau.