#1
How can i modify and old Boss SD-1 to better suit bass and is it possible to do it by just changing the Tone knob.

Right now i lose so much of my bottom end which sucks for my bass.

http://www.freeinfosociety.com/electronics/schemview.php?id=169

^schematics
Gear:
Washburn RB2500 (5 String)
Yamaha BB400 Fretless (1981)
Carlo Giordano 3/4 Upright (White)
Cort Action 4 (Stereo-fied)
Orange Bass Terror 500
Orange 1x15 Cab
Boss GT-6 Bass Multi-effects
#2
I'll pitch in..

Replace C3 with .15uf

Who's next?
Quote by kyrreca
If your EQ looks like this your audience will look like this
#3
Increase the input capacitor, definitely. Also, increasing the value of the .01 cap in the feedback loop of the second op-amp would help give you more bass.