In this instructable I'll show you how to mod your boss ds-1 in only three steps and alter it's sound character radically. I call it the grit mod and it's part all-seeing eye mod and part my own half assed tonestack mod.
Step 1: Swapping the Clipping Diodes
By exchanging one or both of these to LED, the character of the distortion is changed to a softer less fizzy distortion, more "tube like" as some like to say.
I started by desoldering D5 and exchanging it with a LED, the result was a more growling distortion with a lot less gain, instead of breaking into crazy fizzy distortion right away the distortion knob went from almost clean with some dirt to full on distortion with a bit of fizz on top, it also made the bass response better, and the dynamic range got a lot bigger, you can go from clean by rolling off some volume on your guitar and by playing a bit harder it starts to break up.
After successfuly swapping D5 I decided to go ahead and alter D4. This time I did it the all-seeing eye way by desoldering the +side of the diode, soldering in the +side of a LED and then soldering their loose legs together.
this gave me a bit more gain, some more volume on the volume knob and a softer more fuzzlike top end.
Step 2: Altering the Tonestack
I did this by adding an adjustable resistance parallel to R16, changing the value of R16 changes the mid scoop, in original R16 is 6.8kohm but if we change it to 1kohm the filter curve is flat and the mid scoop is gone, and if we change it to 500ohm we will get a mid boost, so I just soldered on a 220kohm potentiometer I had lying around, what it does is that it allows you to adjust the mid scoop from the original scoop to mid boost, giving you a lot more control over the tonestack.
Step 3: Drilling a Hole for the Potentiometer
good luck to you