If you are handy with a soldering iron you really need to check these out. I did the "outlaw" mod to a DS1 and now it sounds cool, nothing like the other mods I've done in the past. It's still "gainy", but not harsh or fuzzy. The tone knob no longer is a "fizz" knob.
I need to put the SD1 thru it's paces tomorrow, but from what I heard it sounds more organic and open.
www.machineheadpedals.com