After two years of development, the new Reference 160M (REF160M) Monoblock power amplifier is unlike any other amplifier you’ve ever heard in terms of construction, appearance, and sound, yet it is unmistakably an Audio Research product. It features a refined audio topology with fewer, better components in the signal path compared to previous designs, switchable ultra-linear/transistor operation, proprietary automatic biasing, output tube monitoring and protection, an advanced power meter, and much more. Audio Research amplifiers have never offered this level of functionality before.

Audio Research designers aimed to create a new aesthetic that complements the REF6 preamp’s appearance, while also incorporating the GhostMeter™, which displays the illuminated KT150 vacuum tubes. While the GhostMeter™ allows you to see the output tubes, it also features an innovative dual-layer construction and unique etched markings, forming an integrated power meter. The power meter’s output level markings are illuminated by concealed LEDs with adjustable brightness. The REF160M includes an etched cover with an integrated fan to cool the heat generated by the four (4) KT150 output tubes and two (2) 6H30 driver tubes. Solid-state power conditioning was chosen for improved efficiency, stability, and reliability

Understandably, the best path is the shortest path. Audio research engineers have created a new audio circuit topology with the shortest signal path and the fewest components. These components are not only the best, but many are custom-designed for audio research. A special 4-layer circuit board combines these premium components, reducing noise floor to unprecedented levels and incorporating designs previously reserved for our preamplifiers. The result is a new benchmark for musicality in every sound quality standard.

REF160M also features a proprietary automatic bias circuit that, in addition to the supplied KT150, can be used with various types of vacuum tubes, including the 6550, KT88, and KT120, and operates continuously to maintain precise bias of the output tube while also adjusting for tube wear. No further checking or adjustment of the bias is required.

The new REF160M represents a breakthrough in sound, aesthetics, and operation, and is available in a natural (silver) or black finish.

Electronic Specifications

Power output

140 watts continuously from 20Hz to 20kHz.
Total harmonic distortion at 1kHz is typically 1% at 140 watts and less than 0.04% at 1 watt. (Note that actual power output depends on line voltage and “conditions,” i.e., if the power line has high distortion, maximum power will be adversely affected, although this is not significant from a listening perspective.)

Power bandwidth

(-3dB point) 5Hz to 70kHz.

Frequency response

(1 watt-hour is the -3 dB point) 0.5 Hz to 110 kHz.

Input sensitivity

2.4V RMS balanced rated output. (8 ohms, 25.5 dB gain).

Input impedance

200 k ohms balance.

Output polarity

Non-inverting. Balanced input pin 2+ (IEC-268).

Output taps

16 ohms, 8 ohms, 4 ohms.

Output adjustment

The open-circuit load is approximately 0.6 dB 16 OHM (damping coefficient is approximately 14).

Overall negative feedback

14dB slew rate: 13 volts/microsecond; rise time: 2.0 ms

Power requirements

105-130VAC 60Hz (210-250VAC 50Hz) Rated output 400 watts, maximum 700 watts, 260 watts “idle”, 1 watt when off.

TUBES

2 pairs of KT150 (power output V1-4); 2 6H30 (gain stage V5 and V6).

SIZE

Width 17.25 inches (43.8 cm)
Height 10 inches (25.4 cm)
Depth 18.5 inches (47 cm)
Handle Extension 19.25 inches (48.9 cm)

WEIGHT

56 lbs (25.5 kg) net weight
73 lbs (33.2 kg) shipping weight