Sansui BASS & TREBLE Tone Control Board F-2576, F-2577 & F-2578 for AU 9900A / 11000A - used, untested.
The boards are in very-good condition, but they are untested, so what you see you will get it. As you can see on the pictures the boards are partially restored.
If you already have Sansui Amplifier AU9900A or AU11000A, this very important board is the last chance to get one as spare circuit board.
Please look carefully at high resolution pictures, because they are part of description.