The Audio Research SP-11 MKII is one of those iconic preamps that lives in the pantheon of high-end audio gear, revered by audiophiles as a milestone in hybrid design. Released in the late '80s, it represents a perfect fusion of tube warmth and solid-state precision, making it a timeless piece for those chasing that sweet spot between detail and musicality. If you're hunting for a piece of audio history that still holds its own today, this beast should be on your radar.
Production
1985
Condition
9.5/10
Serial No.
77034011
Factory Specs
FREQUENCY RESPONSE
High level input: ±1dB 0.2Hz to 100kHz. -3dB below 0.1Hz and above 200kHz. Phono input: ±.2dB of RIAA 20Hz to 40kHz. ±1dB of RIAA 1.0Hz to 100kHz.
DISTORTION (THD)
Harmonic distortion: Less than .005% at 2V RMS output, 5Hz to 20kHz (Typically less than .001% at midband, phono or line input). Intermodulation distortion: Less than .003% at 2V RMS output
NOISE & HUM
IHF weighted, shorted input: Output (Gain down): 6µV (110dB below rated output). Input (High level): 3µV equivalent input (110dB below 1V input). Phono: 0.15µV equivalent input (76dB below 1mV input)
GAIN
At 1kHz, bypass mode: Phono input to tape output: 46dB (0.2V output from 1mV input). Phono input to main output: 75dB (0.175mV input for 1V output). High level input to main output: 29dB (36mV input for 1V output).
INPUT IMPEDANCE
Phono: Front panel selectable 47K, 100, 30, 10, 3 ohms. Phono input capacitance: 150 pF at 10kHz. High level: 20K ohms or higher, depending on switch functions.
OUTPUT IMPEDANCE
250 ohms main, direct, inverted outputs. 500 ohms tape output. Recommended load 60K ohms and 100pF (20Kohms minimum, 1000pF maximum)
OUTPUT POLARITY
Tape outputs, direct output: Non-inverting. Invert output: Inverting. Main outputs (2): Selectable non-inverting or inverting. All outputs may be used simultaneously.
MAXIMUM INPUTS
Phono: 350 mV RMS at 1kHz, 1200 mV RMS at 10kHz (0.1 second maximum duration, 6dB less if continuous). High level: 25V RMS.
RATED OUTPUTS
2V RMS 1Hz to 100kHz main, direct, inverted outputs. (Maximum 80V RMS at 0.2% THD at 1kHz into 60kOhm load with 2.85V RMS high level input).
TUBE COMPLEMENT
(6) 6DJ8/ECC88
POWER REQUIREMENTS
95-135VAC 60Hz, 190-270VAC 50/60Hz, 130 Watts maximum
DIMENSIONS
(Each chassis, EIA Rack panel mounting) 19" (48 cm) W x 5 ¼" (13.4 cm) H x 10 ¼" (26 cm) D. Handles extend 1 ⅝" (4.1 cm) forward of panel. Interconnect cable extends 4" behind rear of chassis.
WEIGHT
SP-11: 14 lbs. (6.4 kg) Net, 23 lbs. (10.5 kg) Shipping.
SP-11PS: 15 lbs. (6.8 kg) Net, 23 lbs. (10.5 kg) Shipping.
Total: 29 lbs. (13.2 kg) Net, 46 lbs. (21.0 kg) Shipping.
The History of Audio Research
Audio Research Corporation, affectionately known to fans as ARC, was founded by William Z. Johnson, who began designing custom audio electronics in the early 1950’s and who also operated a specialty audio retail store until the mid-1960’s. Johnson’s efforts almost single-handedly revived vacuum-tube designs at a time...
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Packing
We'll deliver this piece in its original factory box, so you can be sure it will be protected just as Audio Research intended.
Shipping
This piece ships to the contiguous United States for a flat rate of $250, which includes our packaging and our insurance. Of course, we'll ship anywhere in the world, just drop us a line and we'll give you an estimate – even if you're just curious.
Stock No.
8796842229981
