TS7 Tube Screamer "Less Drive at Zero" Mod

I typically use my TS7 as an overdrive pedal to give a bit of boost to a clean signal. I have other pedals for the heavier distortion (although the TS7 'hot' mode is handy sometimes). When I firt used the pedal, I thought that putting the Drive control on Zero would pretty much remove the distortion of the pedal. But it didn't really. At least not enough for me. Even on zero, the pedal still put out too much crunch. On zero now, there is just a hint of overdrive, almost inaudible when playing single notes but just a little bit gritty when chording, bending, doublestopping. This mod dropped the distortion level of the pedal at zero to allow me to get the slight overdrive I want and still keep the same upper level distortions for when I might want them. This mod works for me and I make no guarantees that it will work for anyone else. Use it at your own risk.

See Robert Keeley's TS-7 Tone Lok Mods page for more detail.



  1. PARTS: You'll need a 12kohm resistor, a soldering iron, and some solder.
  1. 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.
  1. Remove the two screws holding the large circuit board to the pedal chassis.
  1. 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.
  1. Replace the resistor labled R27 (the green circle) with your 12kohm resistor.

    The websites detailing this mod generally call for a 22k - 27k resistor here. Both of these still left me with too much crunch. I experimented with lower values and 12k is the one that I like best.
  1. That's it. Screw everything back together and you've got a modern TS808 Tube Screamer.


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