Modular Fx Pedal (Fuzz)
"This instructable was created in fulfillment of the project requirement of the Makecourse at the University of South Florida (www.makecourse.com)"
I WANTED TO CREATE A MODULAR FX PEDAL WHERE ONE COULD SWAP/DEVELOP NEW FX AND NOT BE LIMITED TO ONE FX. THIS ALLOWS FOR FULL EXPERIMENTAL CONTROL AT ALL TIMES. TO BEGIN MY FX RACK: I DEVELOPED A FUZZ PEDAL WITH A LOWPASS FILTER
(this is what you will displayed in the instructable but any analog circuit can be implemented to add a different effect)
Supplies
Small breadboard and wires
Resistors ( depends on your desired cut off frequency ), I used 1K ohms.
Capacitors ( depends on your desired cut off frequency ), I used 10uF.
Potentiometers ( depends on your parameters ), I used 10k for the Cutoff | 20k for Volume.
Zener Diode and LEDiode
Two NPN Transistors (2n4493)
9V Battery
Arduino
Servo Motor
IR Receiver and RC
Velcro
Two (1/4") Input jacks + Chords
Speaker
INSTRUMENT WITH 1/4" OUTPUT
Available 3D Printer
Make Your Casing
I have included both the STL files. This process was rather meticulous but it found a way to be pleasing when you were able to import models of your components and not worry about fitting pieces incorrectly.
All there is left to do is Velcro the edges of both the lid and bottom in order to safely secure your circuits.
BUILD YOUR FX CIRCUIT
I have labeled my schematic so that you can follow along very easily.
This simple circuit takes use of a 9 V battery fed into the collector of an NPN transistor, The use of a zener diode biases but also sets a path for feedback! Since in an NPN transistor the base current is amplified by beta. A capacitor is added after our guitar input in order to take off the DC offset. It is done attached into the base of the transistor which allows enough current to allow Ic to flow with our frequency information from the instrument.
Another capacitor is used in order to prevent DC spikes into the following stage, a potentiometer in a capacitor are used to set up a low pass filter which I set the frequency cut off at around (700Hz). The output of this low pass filter will carry our signal to the top of our final transistor. The base of this transistor will be controlled by the output pin of your Arduino to bypass or cutoff the signal depending on your configuration.
Last it is all divided by the final volume knob potentiometer which heads to the output jack.
Code You're Arduino
The first nine lines set up the code (adding libraries for the servo motor and IR Receiver) along with the output pin, IR receiver pin, Servo motor pin.
The following five begin to read from the IR receiver so that in can capture the values sent by the remote control All following lines describe what to do when codes from RC are read, this includes moving the servo motor position and sending voltage.