Audio Research is one of the most dependable brand names when it comes to high-end audio systems. For years the brand has been recognized by audiophiles throughout the world as equipment that delivers clear and consistent quality in music.

What are the specs for the Audio Research SP-9?

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:
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)
Output Polarity:
-
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

What else to know about the Audio Research SP-9?

Hybrid stereo preamplifier with phono stage introduced in 1987 for $1,695 retail.

Brief History of Audio Research

Other Audio Research Products We Often Buy

Typically, StereoBuyers purchases mostly used amplifiers, especially the vintage amps and high-end Audio Research models.

StereoBuyers has purchased tens of thousands worth Audio Research brand equipment since 2014, with individual buys ranging from $100 to well over $50,000. If you are moving, ready to upgrade, or have Audio Research equipment you do not or will not be using, why not contact us today to find out if it is worth good money?

If you are interested in selling your used Audio Research equipment to us in the greater NYC area or Colorado, please click here to fill out a Free Quote Form and we will get back to you. If we agree on terms, we come to meet you where you want, and pay cash.

The following images show actual Audio Research equipment purchased by StereoBuyers.