MXR Distortion III

MXR Distortion III

Project description

Well, all credits for this one go to Aron Nelson for the layout and Analogguru for the schematic! I just condensed the layout a little bit, DIY-Layout style ;)

Verification status

I built it and it sounds really good! Nice and grainy, lots of gain on tap and massive volume!

Mods

Lower C4 to about 10nF to raise the frequency the tone filter can boost/cut. There are reports on the internet about removing C4 but I strongly advise against that since it will turn the tone-knob into a high-shelf with massive amounts of high frequencies.

R6 is the minimum gain resistor, raise it for more distortion.

As with any overdrive, you may want to tinker with the D1 and D2 for other sounds. I settled on replacing D1 with a 1N60 and a 1N4148 in series and D2 with a 1N60.

Read more

...at DIYstompboxes!

Bill of materials

Resistors
R1: 100R
R2: 470R
R3: 4.7K
R4: 2.2K
R5: 10K
R6: 10K
R7: 100K
R8: 33K
R9: 33K
R10: 1K
R11: 2.2M
R12: 1.8M
R13: 100K
R14: 22K
R17: 4.7K
R18: 4.7K
Potentiometers
R15: 20K Linear (B)
R20: 1M Linear (B)
R22: 10K Log (A)
Capacitors
C2: 100nF
C3: 27nF
C4: 22nF
C5: 18nF
C6: 18nF
C10: 47nF
C12: 120pF
Electrolytes
C1: 3.3μF
C7: 100μF
C8: 10μF
C9: 220μF
DIL IC's
IC1: TL072
Diodes
D1: 1N4148
D2: 1N4148
D3: 1N4001
Transistors
Q1: MPSA14
4 jumper wires
15 trace cuts

List

Click here to see the bill-of-materials as a list or download it as a comma separated values file (.csv).

Code

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