STATUS - AVAILABLE
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Description :
The Audio Research SP9 represents a further evolution of the innovative electronic design first embodied in the widely acclaimed SP11 preamplifier. It is an adaptation a part of SP11's patented hybrid technology to a simpler, more economical single-chassis format. Its solid construction, soldering and hard wiring is meticulous. Using just two 6DJ8 vacuum tubes in intermediary gain stages, the SP9 expresses the musicality and natural rightness vacuum-tube preamplifiers have been noted for, yet it does so with the quickness and dynamic vigor of the best solid-state designs. Because its two vacuum tubes are used so conservatively, it will prove to be one of the most reliable and low-maintenance preamps. Although the SP9 contains an on-board power supply, it is a highly advanced, tightly regulated design employing a shielded toroidal power transformer to minimize any potential problems of mechanical noise or hum. Location of this transformer in relation to special low-hum input circuitry has been optimized within the SP9 chassis layout to virtually eliminate transformer-related noise. While it is designed to provide superb playback from phono records, its high-level circuits have also been optimized for other popular input sources. The Audio Research SP9 is virtually overload-proof, insuring maximum enjoyment of today's most dynamic program material. With two tape monitor loops, the SP9 offers the tape-dubbing flexibility so many listeners want but seldom find in an audiophile-grade preamplifier.

The Audio Research SP9 has a more etched, analytical sound than expected. It is wonderfully open and imaging is accurately portrayed. The SP9 does not rob the music of its drama, a common occurrence with most preamplifiers. It presents with no signs of brightness or hardness, but with a relaxed and unforced touch. Each performance retains the excitement, tension, joy and sadness. The emotional impact of music remains intact from its depth and refinement. The SP9 has well controlled extended bass and a sweet treble that never fatigues. The music separates into detailed notes, and the deep and wide soundstage contributes to listening pleasure. The SP9 is one of the most musical preamplifiers that ages well with time and can used as a "reference" preamplifier in many systems. Careful, elegant design, structural simplicity and efficient manufacturing techniques have all contributed to a standard of physical integrity and musical accuracy never before achieved in this price class.

Specifications :
Frequency Response........................+/- 0.5dB, 5Hz to 50kHz
                               ........................-3dB points below 1Hz and above 200kHz
                               ........................Phono: +/- 0.3dB of RIAA, 30Hz to 40kHz
Distortion.........................................Less than 0.01% at 2V RMS output.
              .........................................(Typically less than 0.005% in midband)
Gain................................................Phono input to tape output: 46dB
       ................................................Phono input to main output: 66dB (RIAA +/-25dB)
       ................................................High level inputs to tape output: 0dB
       ................................................High level inputs to main output: 21dB
       ................................................CD Input to main output: 9dB
Input Impedance...............................50k ohms for line inputs
                        ...............................47k ohms for phono (Phono provisions for any value below 47k ohms
                        ...............................or added input capacitance for matching certain magnetic cartridges)
Output Impedance.............................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 (1000mV RMS, 10kHz).
                        ...............................High level inputs essentially overload proof
Rated Outputs..................................2V RMS 5kHz to 50kHz, all outputs
                     ..................................60k ohms load (Main output capability is 50V RMS output at 0.5%
                     ..................................THD at 1kHz into a 100k ohms 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 0.01%
Noise...............................................High level (1): 70 microvolts RMS maximum residual unweighted
        ............................................... wideband noise at main output with gain control minimum
        ...............................................High level (2): More than 100dB below 1V RMS input
        ...............................................(Less than 7 microvolts equivalent input noise)
        ...............................................Phono: 0.12 microvolt equivalent input noise,
        ...............................................IHF weighted, shorted input (78dB below 1mV input)
Tube Complement.............................2 x 6DJ8/ECC88 dual triodes
                          .............................(Hybrid FET/Tube audio circuit, solid-state power supply)
Power Requirements.........................100 to 135 VAC, 60Hz(200-270VAC 50/60Hz), 55 watts max
Dimensions(w x d x h).......................48.5 x 31 x 14 cm
Weight.............................................5kg

Miscellaneous :
Made In...........................................USA
Condition.........................................9/10

Product Information :
http://www.arcdb.ws/SP9/SP9.html
http://www.arcdb.ws/SP9/ARC_SP9_service_bulletin_26.jpg (Operating Instructions)
http://www.arcdb.ws/SP9/ARC_SP9_compatibility_modification.jpg (Operating Instructions)
http://www.arcdb.ws/SP9/ARC_SP9_important_note.gif (Operating Instructions)

Reviews :
http://www.stereophile.com/tubepreamps/739/index.html
http://www.audioreview.com/cat/amplification/preamplifiers/audio-research/sp9-mkii/prd_118177_1591crx.aspx
http://www.arcdb.ws/SP9/ARC_SP9_flyer1.jpg (1st review, page 1)
http://www.arcdb.ws/SP9/ARC_SP9_flyer2.jpg (1st review, page 2)
http://www.arcdb.ws/Common%20Flyers/SP9_SP14/ARC_SP9_SP14_flyer1.jpg (2nd review, page 1)
http://www.arcdb.ws/Common%20Flyers/SP9_SP14/ARC_SP9_SP14_flyer3.jpg (2nd review, page 2)
http://www.arcdb.ws/Common%20Flyers/SP9_SP14/ARC_SP9_SP14_flyer4.jpg (2nd review, page 3)