I recently was asked to play guitar and sing with a small prayer group that gets together once a week. For years my guitar has accumulated dust as has my ability to play it. After digging the old girl out, though, I discovered that the passion is still alive down in there somewhere. The skill has certainly oxidized a bit after so much time on the shelf while I pursue my career in IT and balance that with growing my family. Now, it has taken a depressing amount of labor to haul out the scales and progressions and so on, but picking up new songs has emerged more quickly than I expected. Also, I have noticed that my ear for the sound has matured. The nuance and quiet in music has become more interesting. Now, all of this great and I would likely be very happy with just the renewal of interest in playing and singing good songs. However, an unexpected piece has come into the picture.
While cleaning up my office I unearthed an old stompbox called the Big Muff Pi. (In case you need an introduction: https://en.wikipedia.org/wiki/Big_Muff) Even if you are not familiar with its name, you have almost certainly heard the amazing fuzz that it creates. When I dug it out I guess I got a wild hair to look into bending the circuit a little. I have played with Arduino controllers for long time now and wondered if anyone had thought up some clever way to marry the little microcontroller with this huge sounding pedal. It turns out that among the first videos listed in a search for Arduino pedal mods is a clip by my hero Collin Cunningham that centers around his use of the Arduino to control an MCP41100 digital pot in the place of the Big Muff’s sustain control. This gives one the ability to tremolo the distortion effect. Needless to say I was immediately infatuated. I ordered the chip except I opted to upgrade to a two channel model called the MCP42100 offering two channels of 100k ohm resistance, thus allowing me to control two variables – distortion and tone.
I have the pedal pulled apart now and have added to tremolo circuit in addition to a couple of tweaks to the tone and sonic quality of the pedal itself. In another post (that should be forthcoming next week) I will begin to chronicle the process with images and code snippets in an effort to inspire would-be circuit benders and music nerds. It will have the nice byproduct of allowing me to journal the process a bit and catalog the modification in the event that I return to upgrade the pedal down the road.