Used BELLES 150A Reference Version 2 (also called Ref 2 or V2) stereo power amp designed and built by David Belles. About $2,750 new; I bought it used for $1,350 but no longer have space for anything but desktop computer speakers. In near perfect condition with all original packing, manual, cord, and factory box; no blemishes except that the narrow top edges of a few of the heat sink fins have darker black tone, as if perhaps the original owner touched them up with a Sharpie(?). Marks are not invisible but quite unobtrusive in person and I tried to photograph them as best I could. (Second-to-last picture; marks are on heatsink fins #5 and #9 from the front.) That's the only flaw keeping it from a 10/10.
I spoke to David Belles and based on the serial number he guessed that the unit is about four years old. I asked him if it would make any sense to send it to him for a checkup, and he said, "Why? That amp is designed and built to work flawlessly for many years. A checkup would be a waste of your money and my time."
These amps supposedly require around 300 hours break-in time so this unit might not be fully broken in. The original owner said he hardly used it and I also hardly used it.
Original factory power cord is included (unused).