The Reference 80S stereo amplifier continues Audio Research’s latest design effort in creating a vacuum-tube amplifier that not only redefines ultimate music reproduction, but does it in an incredibly beautiful package. Outwardly, the 80S shares the same dimensions as the 160M. A single shallow whisper fan is built into the bottom plate. Flexibility is built-in, too, with XLR and SE inputs, 4-8-16 ohm output taps, 12V input and output triggers, RS232 input, tube hour meter, switchable fan speeds, and defeatable auto-off function. The 80S was created for the music lover who does not require the output power of its larger siblings, the Reference 160S stereo and 160M mono amplifiers. The 80S continues the design ethos, includ- ing dual GhostMeters® that float in front of four KT150 output tubes. Extruded panels, a vital part of the all-aluminum chassis, provide rigidity and beauty. The feature set is the same as the 160S, including a proprietary auto-bias circuit that adjusts for not only tube age, but for powerline voltage swings. There is fusing of the output tubes, single-ended and bal- anced inputs for flexibility, switchable Triode-Pentode operation to accommodate loudspeakers and per- sonal preference, output tube monitoring, and inclusion of an hour meter so you know how many hours are on the tubes–like an odometer for your amp. This is a tube amplifier that does not require fiddling, it is meant to be enjoyed. The built-in 12V trigger turns the 80S on or off when connected to a modern preamp with a 12V trigger. Specifications POWER OUTPUT: 75 watts per channel continuous from20Hz to 20kHz. 1kHz total harmonic distortion typically 0.6% at 75 watts, below 0.05% at 1 watt. Approximate actual power available at ‘clipping’ 76 watts (1kHz). (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 very critical.) POWER BANDWIDTH (-3dB points): 7Hz to 60kHz. FREQUENCY RESPONSE (-3dB points at 1 watt): 0.7Hz to 75 kHz. INPUT SENSITIVITY: 1.4V RMS BAL for rated output. (25 dB Bal gain into 8 ohms.) INPUT IMPEDANCE: 300K ohms Balanced. OUTPUT POLARITY: Non-inverting. Balanced input pin 2+ (IEC-268). OUTPUT TAPS: 8 ohms, 4 ohms. OUTPUT REGULATION: Approximately 1.0dB 8 ohm load to open circuit (Damping factor approximately 8). OVERALL NEGATIVE FEEDBACK: 15dB. SLEW RATE: 10 volts/microsecond. RISE TIME: 4.0 microseconds. HUM & NOISE: Less than 0.06mV RMS – 112dB below rated output (IHF weighted, input shorted). POWER SUPPLY ENERGY STORAGE: Approximately 520 joules. POWER REQUIREMENTS: 105-125VAC 60Hz (210-250VAC 50Hz) 410 watts at rated output, 500 watts maximum, 230 watts idle. TUBES REQUIRED: 2 – Matched pair KT150 – Power Output; 2 – 6H30 Driver. DIMENSIONS: 19" (48.3 cm) W x 8.75" (22.2 cm) H x 19.5" (49.5 cm) D. Handles extend 1.5" (3.8 cm) forward. WEIGHT: 47 lbs. (21.3 kg) Net; 63 lbs. (28.6 kg) Shipping. Reviews If you crave an unexaggerated and essentially honest rendition of a recording, this amplifier pairing must be heard. more... If you have a yearning for Big Boy Audio Research, but don’t want or need the additional power and the increased size, space, heat and price tag that top-end amplification requires, the Reference 80S is perfect. This is the first step on the Audio Research Reference power amplifier ladder, and I can’t help but feel that while it is for many the only step they’ll ever need to take, for others the excellent Reference 80S will be the first step into a world of the highest in high-end audio. more...
