Audio Research Reference 160M MK2 Tube Mono Power Amplifier

Reference 160M – Vacuum tube Monaural power amplifier

After two years in development, the new Reference 160M (REF160M) Monoblock Power Amplifier is built like no other, looks like no other, and sounds like no other amplifier that you have ever heard, but it is unmistakably Audio Research. It features a refined audio topology with fewer and better components in the signal-path than in previous designs, switchable Ultralinear/Triode operation, proprietary auto-bias, output tube monitoring and protection, an advanced power meter, and much more. This array of features has never been offered before in an Audio Research amplifier.

The designers at Audio Research wanted to create a new style that would complement the look of the REF6 preamp while also featuring a transparent faceplate that allows a view of the glowing KT150 vacuum tubes. While this window allows you to see the output tubes, it also incorporates an innovative dual-layer construction with distinctively etched markings that create an integrated power meter. The power meter’s output-level markings illuminate via hidden LEDs, and the illumination brightness is adjustable.

The REF160M includes a sculpted 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 regulation was chosen to provide increased efficiency, stability, and reliability. The power supply stage uses a newly developed High Energy Capacity Transformer and a hefty bulk storage-capacity network to provide extremely high current on demand for transient peaks and intense dynamics, as well as for prodigious bass depth and authority.

It is understood that the best path is the shortest path. Audio Research engineers created a new audio circuit topology with the shortest signal path and the fewest components. Those components are not only the best available, many are custom made for Audio Research. Incorporating these quality components is a special 4-layer circuit board that lowers the noise floor to unprecedented levels, and a design which was previously reserved for use in our preamplifiers. The result is a new benchmark in musicality in every criterion of sound quality.

The REF160M also features a proprietary auto-bias circuit that works with various tubes types, including 6550, KT88, and KT120, in addition to the supplied KT150 and works constantly to maintain precise bias of the output tubes, while also adjusting for tube wear. There is no need to check or adjust bias ever again.

The new REF160M breaks new ground sonically, aesthetically and operationally, and will be available in Natural (Silver) or Black finishes.

Technical Specifications:

POWER OUTPUT

• 140 watts continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 1% at 140 watts, below 0.04% at 1 watt. (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not critical).

POWER BANDWIDTH 

• (-3dB Points) 5Hz to 70kHz.

FREQUENCY RESPONSE

• (-3dB points at 1 watt) 0.5Hz to 110kHz.

INPUT SENSITIVITY

• 2.4V RMS Balanced for rated output. (25.5 dB gain into 8 ohms).

INPUT IMPEDANCE

• 200 k ohms Balanced.

OUTPUT POLARITY

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

OUTPUT TAPS

• 16 ohms, 8 ohms, 4 ohms.

OUTPUT REGULATION

• Approximately 0.6dB 16 OHM LOAD TO OPEN CIRCUIT (Damping factor approximately 14).

OVERALL NEGATIVE FEEDBACK

• 14dB SLEW RATE: 13 volts/microsecond RISE TIME: 2.0 microseconds.

POWER REQUIREMENTS

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

TUBES REQUIRED

• 2 matched pair KT150 (Power output V1-4); 2 6H30 (Gain stage V5 and V6).

DIMENSIONS

• Width 17.25” (43.8 cm)

Height 10” (25.4 cm) 

• Depth 18.5” (47 cm)
• Handles Extended 19.25” (48.9 cm)

WEIGHT

• 56lbs (25.5 kg) Net
• 73lbs (33.2 kg) Shipping