The boss SD-1 is an extremely under-rated pedal. I first started looking into buying one after the DS-1 mods as my next project and searched arround for mods. It first came to me to look on Robert Keeleys website, and sure enough he had a mod (http://www.robertkeeley.com/audio6l6/sd1mods.html) but I figured I'd try something different first and work up to it to get some more modifying experience. The general mod that seems to be popular is to make the SD-1 to Ibanez Tube Screamer 808 specifications, and there were two main sites that offered this:

• http://www.guitarfaq.com/index_v2-7-5.html
• http://groups.msn.com/guitarpage/guitareffectscorner.msnw which happens to be written by a good friend of mine, Kevin Godfrey from Tone-jam.com! (Do check out his GE-7 sniper mods, if you have a GE-7 without it snipered...well...I aught to slap you)
• I'll also be using the Keeley mod http://www.robertkeeley.com/audio6l6/sd1mods.html
• In the future I will be trying the Fulldrive II mod http://www.guitarfaq.com/index_v2-7-30.html

Anyway, the main difference between the two mods is that the GuitarFAQ one uses an electrolytic capacitor in C10 while Kevins mod uses a few different resistors and capacitors (however, out of the two I would recomend doing Kevin's mod as its a lot better in my opinion). I'll be showing you how to do the TS808 mods, the Keeley mods and in the future I'll be trying the fulldrive 2 mod.

Lets get cracking!

GuitarFAQ mod
Kevin's mod
Keeley mod
Fulltone II Conversion
Op-amps

Thanks and acknowledgements;

• The original author of the 'GuitarFAQ mod, as it is currently unknown
• Kevin from Tone-Jam for the tubescreamer mod - Havn't been able to get in contact with you about this Kevin, let me know if you want me to take it down.
• Robert Keeley for being such a cool guy and allowing re-posting of his mods
• Brian Wampler from http://www.indyguitarist.com/ for allowing me to use the Fulltdrive II mod