Audio Research Reference 80S Stereo Power Amplifier

The Reference 80S stereo amplifier delivers Audio Research’s signature vacuum-tube performance in a more accessible design. Using two KT150 tubes per channel in a fully balanced differential circuit it provides rich harmonics, deep bass, dynamic contrast and low distortion against a quiet background. Features include proprietary auto-bias, switchable Triode/Pentode modes, balanced and single-ended inputs, tube monitoring and extensive connectivity options. Built with a four-layer circuit board and hand-assembled in Minnesota, the 80S combines advanced engineering, elegant styling and user-friendly operation to elevate the performance of high-end loudspeakers with immersive, lifelike musical reproduction.

Technical Specifications:

Power Output: 70 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) 7Hz to 68kHz

Frequency Response: (-3dB points at 1 watt) 0.7Hz to 94kHz

Input Sensitivity: 1.4V RMS Balanced for rated output. (25.5 dB gain into 8 ohms). RMS SE for rated output. 

Input Impedance: 300k ohms Balanced; 75k ohms Single-ended

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

Output Taps: 4, 8, 16 ohms

Output Regulation: Approximately 1.0dB 16 Ohm Load to Open Circuit (Damping factor approximately 8)

Overall Negative Feedback: 15dB

Slew Rate: 10 volts/microsecond

Rise Time: 4.0 microseconds

Power Requirements: 105-130VAC 60Hz (210-250VAC 50Hz) 420 watts at rated output, 280 watts in Triode mode, 221 watts at “idle”, 3.6 watts off Units for Japan: 100VAC 50/60Hz 

Tubes Required: 2 matched pair KT150 (Power output V1-V4); 2 6H30 (Gain stage V5, V6)

Dimensions:

Width: 18.5” (47 cm) chassis; 19.0” (48.26 cm) faceplate.

Height: 10.5” (26 cm)

Depth: 18.5” (47 cm) 

With handles & connectors: 21” (53.3 cm) 

Weight:  62 lbs. (28.2 kg) Net; 73 lbs. (32.7 kg) Shipping