For christmas gift to my brother I thought I’d try to make a guitar effect pedal. The main feature would be to have a nice sounding distortion effect, classic rock fuzz. I also found an article on Instructables by Harrymatic discussing adding a timer IC to the circuit to create a sound slicing/chopping kind of effect. This construction is based on his ideas.
So what you need is an amplifier IC, I used an LM386 circuit which can amplify a signal up to 200 times. To be able to control the amplification and the output signal, two potentiometers (resistors with variable resistance) acts as gain and volume controls. The sound slicing effect is created by a NE555 timer circuit which flips the voltage on its output pin high and low in a repeating fashion. The frequency of this is determined by a third potentiometer which is glued to a “effect rate” knob.
Depending on the state of the FX On/Off switches, pin 6 of the amplifier IC is fed by either a constant feed from the power source or a chopped up square wave from the timer IC.
So first step to try this out was connect everything on a breadboard.
If you buy your ICs with DIL8 sockets they will fit nicely on a standard breadboard. An important lesson from this setup is that you must ground both your input jack coming from your instrument and the output jack going to headphones/speakers/amplifiers or else you will get very disturbing hizzes and noises.
For more detail: Hermanizer Power Pedal – A DIY Fuzz Box