REF-2 MkII

About the REF-2 MkII

The Audio Research Reference Two Mk II is a large, single-box, fully balanced vacuum-tube preamplifier measuring 19"W x 7"H x 15.5"D and weighing 31 pounds. It features a sophisticated internal layout with four separate circuit boards isolated to reduce interference and allow modular upgrades. The preamp uses six 6H30 triode tubes along with a 5AR4 and 6L6GC in the power supply, with an estimated tube life of 4000 hours. It offers a frequency response from 0.5Hz to 60kHz, distortion less than 0.015%, and noise 100dB below 2V RMS balanced output. The gain control is a spring-loaded two-way switch with 125 increments, and the balance control operates similarly with fewer increments. Front panel controls include input and record selectors, power on/off, mute, phase switches, and a switch to select balanced or single-ended inputs per source. The preamp supports eight inputs (balanced and single-ended), two main outputs, and a record output. It includes a remote control duplicating most front-panel functions. The Reference Two Mk II is highly regarded for its musicality, clarity, imaging, and dynamics, making it a benchmark in high-end tube preamplifiers.