Audio Research Reference 160S Stereo Poweramplifier

Audio Research Reference 160S Stereo Power Amplifier 140 Wpc Ultralinear or 70 Wpc Triode Operation With Auto-Bias, Dual GhostMeters, and Eight KT150 Output Tubes The Audio Research Reference 160S brings the architecture and feature set developed for the REF160M monoblock into a single stereo chassis. Its fully balanced circuit topology uses eight KT150 output tubes and four 6H30 gain-stage tubes, delivering approximately 140 Wpc in Ultralinear mode or 70 Wpc in Triode mode. The 160S gives you more than one way to integrate it into a serious system. Balanced XLR and single-ended RCA inputs accommodate a wide range of preamplifiers, while dedicated 4-, 8-, and 16-ohm output taps provide appropriate connections for different loudspeaker loads. A 12 V trigger and RS-232 interface support remote and system-control installations. Ultralinear or Triode at the Touch of a Button A front-panel control switches the Reference 160S between Ultralinear and Triode operation. Ultralinear mode provides approximately 140 Wpc, while Triode mode provides approximately 70 Wpc, allowing the owner to choose between the two operating modes without changing tubes or making internal adjustments. Automatic Bias Control Audio Research's auto-bias circuit eliminates routine manual bias adjustment. Once factory-set, the circuit continually compensates to maintain the proper bias as the KT150 output tubes age. A front-panel Tube Monitor function provides a convenient way to check the operating status of all eight output tubes. Dual GhostMeters Dual GhostMeters place the power-meter displays in front of the eight KT150 output tubes, giving the 160S the distinctive visual architecture introduced with the REF160M. Meter illumination can be adjusted through four brightness levels, including off. Designed for Real-World System Integration The Reference 160S includes selectable balanced or single-ended operation, switchable high/low fan speed, and a defeatable auto-shutoff function that turns the amplifier off after two hours without a detected signal. Two internal fans provide forced-air cooling, while the rear panel includes 12 V trigger connections and RS-232 control for integration with automated systems. Features 140 Wpc continuous output from 20 Hz–20 kHz in Ultralinear operation Approximately 70 Wpc in Triode operation Eight matched KT150 output tubes and four matched 6H30 gain-stage tubes Fully balanced circuit topology Proprietary automatic bias circuit with continuous compensation as output tubes age Switchable Ultralinear and Triode operating modes Dual GhostMeter power meters Output-tube monitoring for all eight KT150 tubes Balanced XLR and single-ended RCA inputs 4-, 8-, and 16-ohm speaker output taps Four-level meter illumination adjustment, including off Selectable high/low fan speed Defeatable two-hour auto-shutoff 12 V trigger input/output and RS-232 control Four-layer circuit board Included Accessories Eight matched KT150 output tubes Four matched 6H30 tubes 20 A IEC 12-gauge AC power cord 7/64" hex driver for initial tube-cage removal Specifications Power Output: 140 Wpc continuous from 20 Hz–20 kHz; 1 kHz total harmonic distortion typically 1% at 140 W, below 0.04% at 1 W; approximately 70 Wpc in Triode mode Power Bandwidth (-3 dB Points): 5 Hz–70 kHz Frequency Response (-3 dB Points at 1 W): 0.5 Hz–110 kHz Input Sensitivity: 2.4 V RMS balanced for rated output; 25.5 dB gain into 8 ohms Input Impedance: 300k ohms balanced; 100k ohms single-ended Output Polarity: Non-inverting; balanced input pin 2+ (IEC-268) Output Taps: 4, 8, and 16 ohms Output Regulation: Approximately 0.6 dB, 16-ohm load to open circuit; damping factor approximately 14 Overall Negative Feedback: 14 dB Slew Rate: 13 V/microsecond Rise Time: 2 microseconds Power Requirements: 105–130 VAC, 60 Hz; 875 W at rated output, 700 W in Triode mode, 500 W at idle, 3.6 W off Tubes Required: Eight KT150 output tubes (four matched pairs); four 6H30 gain-stage tubes Dimensions (H × W × D): 10.25" x 19" x 21.5" (26 x 48.26 x 54.61 cm); 24" (60.96 cm) deep with handles and connectors Weight: 100 lb. (45.4 kg)