Audio Research SP20 Stereo Tube Preamplifier w/remote Silver

For sale is my Audio Research SP20 Stereo Preamplifier in silver.  Unit is in excellent used condition. Always used in a pet free home.  Preamp works flawlessly.  I installed a new set of tubes back in November 2023 and they currently have only 135 hours on them. 

I'll ship with original packaging and will include original remote and power cord.  Shipping charges will be determined after purchase and I'll let you choose whichever carrier you prefer, but shipping charges will be responsibility of buyer. 

Please reach out to me with any questions.  

Following is some additional info regarding this preamp:

The SP20 is fully balanced, pure Class-A with zero feedback. There are seven levels of voltage regulation, a large power supply, and a very low-noise R-core power transformer. Both the line and phono stages feature low-noise JFET inputs and 6H30 (2 per section) outputs. The latest high performance coupling and bypass capacitors are used in both stages. Both the line stage and phono preamplifier offer extraordinary frequency response and low noise. The phono section provides 58dB of gain, so the SP20 can be used with a wide variety of phono cartridges, including moderately low output moving coils.

About this product

Specifications

• FREQUENCY RESPONSE
• Line: ± 0.3dB 2 Hz to 80 kHz; -3dB 0.8Hz to 220 kHz. Phono: ± 0.1dB of RIAA 10Hz to 20kHz; ± 0.4dB 5Hz to 80kHz. Headphone: ± 0.05dB 20Hz to 20kHz; -3dB 0.8Hz to 220kHz.
• DISTORTION (THD)
• Line: < .003% at 2V RMS, Bal output. Phono: < .005% at 3V RMS output, to Record output. Headphone: < .009% at 1V RMS output.
• NOISE & HUM
• Line: <-101dBV volume at max. Phono: < -77dBV to Record output. Headphone: < -88dBV volume at max.
• GAIN
• Line: 13.8dB, Processor: 0dB. Phono: 58dB @ 1KHz to Record output. Headphone: 11.3dB.
• INPUT IMPEDANCE
• 120k ohms Balanced, 60k ohms SE; Phono impedance programmable (100, 200, 500, 1000 or 47k ohms w/200pf unbalanced).
• OUTPUT IMPEDANCE
• 500 ohms Balanced, 250 ohms SE; 1000 ohms Record Out SE; <.05 ohms Headphone SE.
• OUTPUT POLARITY
• Non-inverting
• MAXIMUM INPUTS
• Line: 19V RMS Balanced, 9V RMS SE. Phono: 70mV RMS at 1kHz.
• RATED OUTPUTS
• Line: 2V RMS (1V RMS SE) into 200k ohms balanced load (maximum balanced output capability is 18V RMS at less than .5% THD+N at 1kHz.). Phono: 0.5V RMS into 100k load at Record output (maximum output capability is 25V RMS). Headphone: 6V RMS maximum into 30 to 300 ohm load.
• POWER SUPPLIES
• Electronically regulated low and high voltage supplies. Automatic 30 sec. warm-up/brown-out mute. Line regulation better than .01%.
• TUBE COMPLEMENT
• (4) 6H30
• POWER REQUIREMENTS
• 100-125VAC 60Hz (200-250VAC 50/60Hz) 77 watts maximum. Standby 2.7 watts.
• OTHER
• Channel Separation: Line: > 105dB Balanced output. Phono: > 76dB to Record output. Headphone: > 62dB. Signal to Noise Ratio: Line: > 125dB Balanced output. Phono: > 94dB to Record output. Headphone: > 110dB.
• DIMENSIONS
• Width 19” (48 cm) Height 5.25”(13.4 cm) (standard rack panel) Depth 16.5”(42 cm).
• WEIGHT

There is also an excellent review of this pre-amp on Stereophile.