.::BADASS DISTORTION PEDAL::.
Hey, i am Emir, a persian microelectronix engineer, expert, scholar, experimentalist, programmer, innovator, assembler, supervisor & hobbyist.
& im so sorry because my english is not good... :P
This is my own fuzz-unit effect... :v
these kind of stompboxes are interesting because they even make human voice, awesome. what about guitars...! :3 And specially for Distorted-Basses like Marylin Manson's songs/themes or others...
When people uses Distortion word for a sound, it means an audio signal too amplified so some clips occurred in both sides of cycle-swings. this operation called Overdriving. And it is different in each harmonic coefficient amplification ratio.
This pedal contains some potentiometers to adjust between Clean, Soft drive, Hard drive (distortion) and Fuzzy.
You can find other related & similar fuzz boxes in http://fuzzcentral.ssguitar.com
Step 1: Understanding the Circuit
My effect is a lil bit different. cause of an active inverting op-amp amplifier in first stage (You can see the lowest gain amplification affect in second image), A passive Low-Pass filter in middle (removed) & an A class, self bias amplifier at last (removed).
How it works?
well, this is so simple. i said that over-driving situation for amps. And now, there is "Drive" pot in input stage. it will inject signal how much we want. Or in other meaning controlling the variable drive ratio (Av (gain)). (Because our +Vcc is fixed). Cause it is changeable in two first transistors by feedback resistor and related RC network. (Attack pot & 22uF capacitor). Also this RC net do anything else that we called it helix resonate. just try some high Attack vox with it.
About the first step, i gathered tens of distortion peal resonance tank schematics, assigned in a table with R & C parameters with "Resonance tank of different distortion pedals" title in PDF configuration to make a professional/trade-mark sound... ^_^ USE IT WELL
REMOVED [Anyway... Recommended button makes soft/hard distorted sound. this is an integrator. but i don't use it because it will mix with bass harmonix (And just bass in bass harmonics like there was no treble signals @ all!!!)
And then, the Bias pot for embedding perfect collector-emitter voltage (Vce) about Vcc/2 for good biasing and amplifying both +/- cycles. (Occasionally in mid rang). i notice that again that Re=100R.]
Other references called that pot "Mud".
REMOVED [Check out the oscilloscope signal. last amp is a common emitter, A class, self bias, low voltage and low frequency signal amplifier. so there is 180 degrees phase difference.]
Step 2: Accomplishing & Assembling
You can build your own effect PCB & box. (I didn't. 1000-holes-board is sufficient ^_\\ it wasn't important to me how it's look like) cause im engaged with other important projects. they are just for fun... :v
canister is an adapter case modified by myself, And label/vinyl is available
Have a nice day & good luck. ;)