audio research

Tube mono power amplifier.

From the ARC website

The VS 55 and 110 power amplifiers have been instrumental in bringing new customers to Audio Research - customers who are looking for exceptional sound and the look of a classic vacuum-tube amplifier. In 2003, we began receiving requests for a monoblock power amplifier similar to the VS series, with more power and a reasonable price.

We are proud to annouce the VM220 monoblock power amplifier, which represents the capstone of this series, offering performance and features that go well beyond its companion products in the VS series. Output is conservatively rated at 200+ watts.

While similar in size and appearance to the VS110, the VM220 uses an additional 6N1P front-end tube. Its purpose is to provide the differential signal for true balanced operation, a first for this series. With both balanced and single-ended inputs (switch selected), the VM220 will be compatible with every Audio Research preamplifier. In addition, the VM220 uses a super-wide-bandwidth output transformer to provide better frequency extension, explosive musical dynamics, and more powerful bass extension and speed. The VM220 has classic tube sound virtues, but with greater extension, air and a robust bass response that goes far beyond anything you have heard from the VS series before.

Like all our amplifiers, the VM220 offers 12V input/output connections for remote start-up installations, and a heavy-duty 12 gauge detachable line cord with 20-amp IEC connector. Output taps are 0-4-8 ohms. The VM220 also had a hot-start lock-out feature which prevents the amplifier from being restarted too quickly in the event of inadvertent shutdown or power failure - thereby preventing undue stress to the output tubes. The VM220 comes standard with an anodized top plate and exposed tubes, like the VS series; an optional perforated tube cage is available for $250 U.S. suggested retail.

The VM220 is sure to become another classic design from Audio Research.




Perforated tube cage $250

MSRP (US new retail)


Power output 200 watts per channel continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 0.5% at 200 watts, below .05% at 1 watt. Approximate actual power available at "clipping" 230 watts (1kHz).
Power bandwidth (-3dB points) 10Hz to 100kHz.
Frequency response (-3dB points at 1 watt) 1.0 Hz to 140 kHz.
Input sensitivity 1.8V RMS Single-ended or balanced for rated output. (26.7 dB gain into 8 ohms.)
Input impedance 100K ohms Single-ended, 200K ohms balanced differential.
Output taps 4, 8 ohms
Output regulation Approximately 0.8 dB 8 ohm load to open circuit.
Overall negative feedback 14dB
Damping factor Approximately 12.
Slew rate 25 volts/microsecond
Rise time 1.5 microseconds
Hum & noise Less than 0.2mV RMS - 106dB below rated output (IHF weighted, input shorted).
Power supply energy storage Approximately 332 joules.
Power requirements 105-125VAC 60Hz (210-250VAC 50Hz) 620 watts at rated output, 900 watts maximum, 400 watts at "idle".
Tube complement (4) 6N1P, (4 matched pairs) 6550C
Other Balanced and singled ended inputs, switch selected
12V input/output connections for remote start-up installations
12 gauge detachable line cord, 20 amp.
IEC connector
Dimensions 17.5" (44.5 cm) W x 7.9" (20.1 cm) H x 19" (48.3 cm) D. Rear connectors extend .88" beyond chassis.
Weight 54.7 lbs. (24.9 kg) Net; 63 lbs. (28.6 kg) Shipping.