I owned an SP-11 mk II for a number of years. In its time it was one of the best preamplifiers available, and it gave me a lot of pleasure. It is still good, but I believe it to be surpassed by the better preamps out there now (I replaced it around 1990 with a Jadis JPL/Vendetta SCP-2B combination, as the tubed JPL was more to my liking and the Vendetta was a quieter and better phono stage than the ARC's). It is not really as liquid or dimensional as a great tube preamplifier, and its solid state circuitry is not as good as more recent mainly solid state preamplifiers I have heard, like the Lamm L2 (the tube in that unit is in the power supply) and Boulder units. It's very good as far as vintage equipment goes, as Elizabeth says, and it does have some very useful features that you don't find in modern units (especially for listening to vinyl, including a mono switch and a knob in the front for some cartridge loading). I have found it interesting that it does not seem as prized in the used market as the SP-10 that it replaced in the ARC line.
