AUDIO RESEARCH SP-9

Second-hand, in good condition, without its original package. Supplied with its original package.
Hybrid tube/FET stereo preamplifier


Specifications
Frequency response: High Level Section: ±.5dB, 5 Hz to 50 kHz, - 3dB points below 1 Hz and above 200kHz. Phono: ±.3dB of RIAA, 30Hz to 40kHz.
Distortion (THD): Less than 0.1% at 2V RMS output. (Typically less than 0.005% in midband)
Noise & hum
High Level: (1) 70 µV RMS maximum residual unweighted wideband noise at main output with gain control minimum (98 dB below 5V RMS output). (2) More than 100dB below 1V RMS input (less than 7µV equivalent input noise). Phono: 0.12 µV equivalent input noise, IHF weighted, shorted input (78dB below 1 mV input).
Gain SP9: Phono input to tape output: 46dB. Phono input to main output: 66dB. High level inputs to tape output: 0dB. High level inputs to main output: 20dB. SP9 MKII/III: Phono input to tape output: 46dB. Phono input to main output: 67dB. High level inputs to tape output: 0dB. High level inputs to main output: 21dB. CD input to main output: 9dB.
Input impedance
SP9: 50K ohms line inputs. 40K phono (Phono provisions for any value below 47K ohms or added input capacitance for matching certain magnetic cartridges). SP9 MKII/III: 50K ohms line inputs. 47K phono (Phono provisions for any value below 47K ohms or added input capacitance for matching certain magnetic cartridges)
Output impedance
SP9: 500 ohms main output. 850 ohms recorder output. Recommended load 60K ohms and 100pF. (20K ohms minimum and 1000pF maximum). SP9 MKII/III: 250 ohms main output. 850 ohms recorder output. Recommended load 60K ohms and 100pF. (20K ohms minimum and 1000pF maximum)
Maximum inputs: Phono, 200mV at 1kHz (1000 mV RMS, 10kHz). High level inputs essentially overload proof.
Rated outputs: 2V RMS 5Hz to 50kHz, all outputs; 60K ohm load (main output capability is 50 V RMS output at 1/2% THD at 1kHz into a 100K ohm load with 5V RMS high level input)
Power supplies:  Electronically–regulated low and high voltage supplies and electronic decoupling. Shielded toroid transformer. Line Regulation better than .01%.
Tube complement: SP9: (2) 6DJ8/ECC88. SP9 MKII/III: (2) 6922
Power requirements SP9: 100-135 VAC 60 Hz (200-270 VAC 50/60Hz) 50 watts max. SP9 MKII/III: 100-135 VAC 60 Hz (200-270 VAC 50/60Hz) 55 watts max
Dimensions: SP9: 19” (48 cm) W x 5 1/4” (13.4 cm) H (standard rack panel) x 10 1/4” (26 cm) D. Handles extend 1 5/8” (4.1 cm) forward of the front panel. Rear chassis fittings extend 7/8” (2.3 cm). SP9 MKII/III: 19” (48 cm) W x 5 1/4” (13.4 cm) H (standard rack panel) x 10 1/4” (26 cm) D. Handles extend 1 1/2” (3.8 cm) forward of the front panel. Rear chassis fittings extend 7/8” (2.3 cm).
Weight SP9: 13 lbs. (5.9 kg) Net; 22 lbs. (10 kg) Frequency response: High Level Section: ±.5dB, 5 Hz to 50 kHz, - 3dB points below 1 Hz and above 200kHz. Phono: ±.3dB of RIAA, 30Hz to 40kHz.
Distortion (THD): Less than 0.1% at 2V RMS output. (Typically less than 0.005% in midband)
Noise & hum
High Level: (1) 70 µV RMS maximum residual unweighted wideband noise at main output with gain control minimum (98 dB below 5V RMS output). (2) More than 100dB below 1V RMS input (less than 7µV equivalent input noise). Phono: 0.12 µV equivalent input noise, IHF weighted, shorted input (78dB below 1 mV input).
Gain SP9: Phono input to tape output: 46dB. Phono input to main output: 66dB. High level inputs to tape output: 0dB. High level inputs to main output: 20dB. SP9 MKII/III: Phono input to tape output: 46dB. Phono input to main output: 67dB. High level inputs to tape output: 0dB. High level inputs to main output: 21dB. CD input to main output: 9dB.
Input impedance
SP9: 50K ohms line inputs. 40K phono (Phono provisions for any value below 47K ohms or added input capacitance for matching certain magnetic cartridges). SP9 MKII/III: 50K ohms line inputs. 47K phono (Phono provisions for any value below 47K ohms or added input capacitance for matching certain magnetic cartridges)
Output impedance
SP9: 500 ohms main output. 850 ohms recorder output. Recommended load 60K ohms and 100pF. (20K ohms minimum and 1000pF maximum). SP9 MKII/III: 250 ohms main output. 850 ohms recorder output. Recommended load 60K ohms and 100pF. (20K ohms minimum and 1000pF maximum)
Maximum inputs: Phono, 200mV at 1kHz (1000 mV RMS, 10kHz). High level inputs essentially overload proof.
Rated outputs: 2V RMS 5Hz to 50kHz, all outputs; 60K ohm load (main output capability is 50 V RMS output at 1/2% THD at 1kHz into a 100K ohm load with 5V RMS high level input)
Power supplies:  Electronically–regulated low and high voltage supplies and electronic decoupling. Shielded toroid transformer. Line Regulation better than .01%.
Tube complement: SP9: (2) 6DJ8/ECC88. SP9 MKII/III: (2) 6922
Power requirements SP9: 100-135 VAC 60 Hz (200-270 VAC 50/60Hz) 50 watts max. SP9 MKII/III: 100-135 VAC 60 Hz (200-270 VAC 50/60Hz) 55 watts max
Dimensions: SP9: 19” (48 cm) W x 5 1/4” (13.4 cm) H (standard rack panel) x 10 1/4” (26 cm) D. Handles extend 1 5/8” (4.1 cm) forward of the front panel. Rear chassis fittings extend 7/8” (2.3 cm). SP9 MKII/III: 19” (48 cm) W x 5 1/4” (13.4 cm) H (standard rack panel) x 10 1/4” (26 cm) D. Handles extend 1 1/2” (3.8 cm) forward of the front panel. Rear chassis fittings extend 7/8” (2.3 cm).
Weight SP9: 13 lbs. (5.9 kg) Net; 22 lbs. (10 kg)