Here's the schematic for the guts of a TS-808 or TS-9/TS-9R (click on the image to enlarge). This circuit omits the footswitch and its c...

Taking apart the TS-9 is straightforward. There are four screws on the bottom, plus 2 more inside to remove. Then, tackle the pots and jacks...

Conversion to TS-808 requires two parts: first, make sure the Op-Amp is a JRC4558 and change it if it is not. I strongly recommend socketing...

The Bass-Boost mod might be the easiest conceptually, but requires a lot of finessing because of the sizes of the elements involved. First, ...

The Level Bypass mod allows you to have a second channel with a different level (output volume) setting. It works by shorting over the level...