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out

Gretsch Controfuzz

Here’s an oddball rare circuit that’s also quite fun. The Gretsch Controfuzz

is an opamp-driven fuzz/distortion unit that allows you to mix the amount of

clean signal with the fuzz signal. The original used a now-obscure 748

opamp. We’ll use a more modern type, but the sound should be the same.

Mods!Diode clipping mods: try different values for D1, and D3. Try different diode types

and LEDs.

The standard TL072 dual opamp is a low-performance part can be swapped for

other dual opamp types.

The R4 resistor sets the gain for the first opamp stage. Try lower or higher values,

or use a pot instead of the fixed resistor. Same goes for R8 which sets the gain

on the second stage.

beavis board project

A100K

Boost

B10K

Distort

C1

100nF3

2

8

1

4

+

-

U1a

TL072

Input

9 volts +

R1100KΩ

R2100KΩ

R510KΩ

VR1B10K

(distort)

D1

1N4001D2

1N4001

R4220KΩ

TL072

in

C2

220pf

R3100Ω

C3

10uf

C4100nF

R6220KΩ

Output

5

7

+

-

U1a

TL072

R7100KΩ

C5100nF

6

R8330KΩ

C6100nF

VR2A100K(boost)

100nF

10KΩ

1N4001

10uf

+

100KΩ

100KΩ

220pF100Ω

220KΩ

100nF

1N4001

220KΩ

100KΩ

100nF

330KΩ

100nF

revision: 1.1 21 August 2008 © 2008 beavis audio research