Boss BD-2 tonestack tweaks for more mids/less bass

[Cliff Schecht]

For years my Blues Driver was my go to pedal for blues rock stuff. It stayed with the gain pretty low and sounded good as a gritty overdrive. Then for about two years I swore off pedals and only played straight into amps, namely a Trainwreck Express I built and fell in love with. But when my band started micing up the amps it was immediately obvious that this amp was too loud. So I built a simple BF Deluxe to run clean and use pedals to color the sound. TBH I missed pedals and have been having a blast tweaking on my pedals/pedalboard.

Anywho, I wanted to use my Blues Driver as my only distortion pedal. It sounded good at the house but when I cranked the gain up and kicked on the pedal with the full band, my sound dropped out completely. Not like the pedal didn't work, the tone was just all bass and treble. Even with a TS808 driving it I couldn't get the darned thing to cut through the mix! The compete lack of mids was really making it unusable for rhythm distorted stuff (blues rock and such).

So I dug into the schematic and compared the mods I had done to the stock schematic and ran a few sims on the tonestack. What I saw immediately was the big mid dip and massively excessive bass boosting that was happening. Long story short I settled on changing R50 to a 100k resistor (really I put a 100k in parallel with the 1M on the board) and replaced R51 with a 47k resistor. This had the effect of really knocking down the boomy bass (especially with a neck pickup) and bringing up the mids to add some much needed cut.

FWIW my pedal was not stock to begin with. The mods I had done before (quoted below) I think are pretty standard changes that were given to me by MartyMart many moons ago. The one mod I had in that I reverted back to stock was changing C100 to 0.047uF (from 0.018uF), but I went back to 0.022uF which again helped tame the bass.

I don't know if others have had problems with this pedal but I really like it now for a good medium gain distortion pedal. It works really well with a DOD250 and/or TS808 in front of it and can cover a lot of territory tonally. Also works decently well with your guitars controls (still has that famous decay issue ).

C14, this is the input cap, increase to 0.1uf ( 100n ) for more full range through the circuit
D3 - change the small Si diode to a 1N4001 for assym clipping here.
D7/D8/D9/D10, remove one of these pairs of small Si diodes and use a single red 3mm LED
This gives more assym clipping and a good "grind" to the top end of the drive pot.