The SL 10 was the second preamp released from Threshold following the tradition of the now legendary NS 10 preamp that was the first from Nelson Pass. The SL 10 is a fully cascode Class A preamp of exemplary build and construction. It set new standards for the time and remains to this day a leading edge preamplifier by any standard one would care to judge. Most appealing, in many people's judgement, is the phono section, which is simply wondrous, and competes with vastly more expensive contemporary stand alone units. That, and the knobs, which may be the most artfully sculpted and supple feeling controls ever put on a consumer electronics device.
Please see the Audiogon Forums review of this preamp for a detailed description of its specifications and many virtues.
The particular example for sale is in flawless operating condition, and comes with the original outboard power supply. The original power cord is not included, though I will include a serviceable cord to provide functionality. It is rated "8" solely because of a few small scratches on the top of the case.
Purchase with confidence from a well established Audiogon trader. I am aware of the Audiogon bluebook value stated for an SL-10, and if you can find one in comparable condition to this for that price, I encourage you to jump on it. To the best of my knowledge, the last one to sell on ebay went for $900. (I prefer not to sell on that site.)