Audio Research D-80 Stereo Power Amplifier

The D-80 tube amplifier blends the musicality and authority of Audio Research’s legendary “D” series with technology derived from the Reference 80S. Featuring a fully balanced differential design with KT150 tubes per channel it delivers rich tonal color, strong bass control, expansive soundstaging and high resolution. Designed as a full pentode amplifier with balanced XLR inputs only it emphasizes simplicity and performance. Auto-bias continuously adjusts for tube age and voltage fluctuations to ensure consistent sound quality. Built, tested and individually auditioned in Minnesota the D-80 offers Reference-inspired performance in a more affordable and streamlined package.

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 SE)

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. 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