Starting in December of 2001 Keeley started to toy around with the Blues Driver. What
he liked was the amount of gain that the pedal had and the complication they engineered
into a fuzz tone pedal. BOSS worked hard to come up with a complex tone. What could he do?
Just little things...but, after a while he found that several of his changes were adding
up to a wonderful improvement in the tone! Cool! What he does is change many capacitors
and resistors to fine tune the sound. He changes the input capacitor to allow more of the
natural bass from your guitar through. That helps with the weak bass problem. He changes
the value of capacitor on the Tone control to make it not so thin sounding when turned up.
It evens out the response of the control. He change the value from 0.018uF to 0.033uF,
then switches in a 0.068uF cap for the Phat switch. He then changes 6 electrolytic
capacitors capacitors for increased smoothness and a little higher quality sound. Lastly,
the old 2nd order harmonic increase trick!!! He changes diodes to make the clipped signal
a little more asymmetrical. Guitar players love even ordered harmonics. They sound best!
All-in-all the pedal sounds much better than before. There is a definite increase in
the sweetness or saturation of the clipped signal. It has more sustain. It is a lot less
fuzzy or cranky sounding and much more tube-like in tone. Best of all with the ceramic
caps changed to silver mica, there is a drop in the background noise level. The
improvement in tone is unmistakable.
Boss BD-2 Blues Driver Mods
This is not all-inclusive in what can be done to the Blues Driver. It is meant to give
an idea of where the tone can be improved or changed. All of the changes are subtle but
when packaged together offer a nice improvement.
D3 Change this 1SS133 to a different (1N4002) diode for asymmetrical clipping. This
adds second order harmonics. This adds to the tube type sound.
D7 D8 D9 and D10 Change 2 of of these diodes from 1SS133 to a single 1N4002. More
second order harmonic distortion. Although the change is slight, it can be perceived.
Keeley actually takes out one of the two pairs and replaces it with a single 1N4001.
C1, C7, C6, C12, C13, and C15 Change this electrolytic capacitor to a 10uF tantalum.
Tantalum capacitors sound better than electrolytic capacitors. Keeley likes these anywhere
there is signal coupling at this high a value. Tantalum capacitors are easy to find in
C14 Increase input coupling capacitor value to 0.1uF for increased bass response from
C100 Here is where Keeley can affect the tone control. He prefers a little more
lower-midrange and bass frequencies through the tone section. You can increase the lower
frequencies by increasing the capacitor value to 0.033uF. Install a switch to add a
0.068uF cap in parallel with this value for the Phat Mode!
Most of the ceramic caps are changed to Expensive Silver Mica (Available through Small
Bear Electronics www.smallbearelec.com or www.mouser.com or www.digiley.com). This is what
makes the Keeley mod sound so good. A noticeable reduction in noise. An increase in the
smoothness and no harshness left. This type of upgrade is not found in anyone's mods. The
best sound is right here.