Audio Research SP-10 - Two Chassis Tube Preamplifier

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Full featured all-tube preamp from Audio Research - featuring no less than 12 tubes in the preamp stage and three in the power supply...

Has a wonderful tube phono stage too so you won't need to use an external phono preamp.

In great condition, the front faceplate is super clean and without scratches or dents. All knobs are clean and the writing is perfect. The top shows a few light scratches.

This unit has been serviced and re-tubed (not by us), but the quality of the work is top notch.

Notes from our technical team:

Removed, cleaned, and reinstalled volume control. Cleaned all controls, swapped a pair of line stage tubes to improve channel balance, full test passed. Detailed chassis. All tubes Electro Harmonic 6922. BH 3/6/20

Our Testing Process for Preamplifiers (All) at SkyFi:

We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.

At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.

Final testing involves putting actual music through the preamplifier We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage Kef speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.