1. PARTS: You'll need a 10kohm resistor, a 100 ohm resistor, a soldering iron, and some solder.
- Open your pedal by taking out the four screws on the bottom. Remove the bottom cover and put it off to one side. Be careful not to lose the spring that will fall out of the switch end of the pedal.
- Remove the two screws holding the large circuit board to the pedal chassis.
4. Carefully lift the large circuit board out of the chassis. The power adapter end will be connected to another board underneath. Pull gently to 'unplug' the large board from the smaller one.
5. Locate the small circuit board next to the output jack and remove the two screws holding it to the pedal chassis. The output jack is soldered to this board so when you pull it out you will also have the jack out of the chassis.
6. Replace the resistor labeled R58 (the blue circle) with your 10kohm resistor and replace the resistor labeled R55 (the yellow circle) with your 100 ohm resistor.
The green arrow points to the JRC4558D chip mentioned earlier.
7. That's it. Screw everything back together and you've got a modern TS808 Tube Screamer.