This is the SP11 MKII version. It is in two parts, the control center and separate power supply. This pre amp sold for an astounding $5995.00 back in 1987!!! Wow could you imagine what something like this would sell for new today! I never thought I would ever part with this highly sought after pre amp. I wish I could keep this, but I need to fund a new pre amp that is more up to date to match the rest of my system. I rated this an 8 even though I can't find any scratches or dents anywhere worth mentioning. This pre amp comes with 6 NOS Amperex 6dj8 Bugle Boy tubes made in the Harleen Holland plant that perform flawlessly and are extremely quite. My speakers are Klipshorns rated at 104 db efficiancy and are DEAD quiet with this pre amp!
Now the best part, I just got this back from Audio Research where they did a complete service, so this piece is good to go for many years of enjoyment! While it was there, I had them alter the impedance values to more realistic cartridge matching. The 47k setting is unchanged for MM cartridges. All the other settings have a 0 added to the values shown on the dial so now the settings are 47k, 1000, 300, 100 and 30. This piece is in unbelievable condition for it’s age. All original packaging and new outer boxes (Audio Research usually always does this when you send them any piece for servicing) with the correct serial numbers on them are included as well as the manual and other documents and pamphlets I collected over the years. You won’t be disappointed in this one. This will ship in 2 boxes. The tubes will be removed from there sockets and placed in foam (supplied from Audio Research) and put under the cover of the control piece. Please take note that Audio Research labeled each tube for a corisponding labeled socket.
As with all vintage electronics, this will be sold as is with no returns. But rest assured, it performs flawlessly.
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Two-chassis hybrid tube/FET stereo preamplifier.
SP-11 MKII (1987)
Gold/champagne faceplate (SP11MKII ) - Taiwan only.
MSRP (US new retail)
$4,995/$5,995 (SP-11 MKII)
Frequency response High level input: ±1dB 0.2Hz to 100kHz. -3dB below 0.1Hz and above 100kHz.
Phono input: ±.2dB of RIAA 10Hz 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: 20Kohms or higher, depending on switch functions
Output impedance 250 ohms main, direct, inverted outputs. 500 ohms tape output. Recommended load 60Kohms 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
Other Filter: 25Hz Hi-pass phono subsonic 6dB/octave rolloff (to eliminate ringing) with transition to 12dB/octave at 10Hz. Front panel switchable phono only.
Dimensions 19" (48 cm) W x 5.25" (13.4 cm) H x 10.25" (26 cm) D (each unit). Handles extend 1 5/8" (4.1 cm) forward of panel. Interconnect cable extends 4" behind rear of chassis.
Weight SP-11: Net 14 lbs. (6.4 kg); Shipping 23 lbs. (10.5 kg)
SP-11PS: Net 15 lbs. (6.8 kg); Shipping 23 lbs. (10.5 kg)
Total: Net 29 lbs. (13.2 kg); Shipping 46 lbs. (21.0 kg)