Here you have a chance to buy Tone Bass - Treble Board F-2576 & F-2577 & F-2578 . The boards are complete but it is untested. The boards were carefully removed from amplifier and as you can se on the pictures, they are without burned elements.
*Those parts / boards are used, and bought long time ago as spare parts, so they could be good for Sansui AU9900 or AU9900A or AU11000 or AU11000A, but I am not sure for what exactly model some part / board is… So before buying, be sure that the part/board you need is exactly the one you plan to buy!