RA Penfold Fuzz Unit

[moosapotamus]

Following some recent discussions on subjects like "dynamics" and "noise reduction", I was tempted to try this out on the breadboard...

R.A. Penfold Fuzz Unit, from the 1994 book "Music Projects".

Two parallel signal paths, a clipping style fuzz and an adjustable gain stage, are both fed into a voltage controlled amplifier (VCA). The fuzz goes to the VCA's input and the gain stage goes to the VCA's control pin. The VCA tracks the player's dynamics and, as a result, the output volume of the fuzz follows the original attack and decay characteristics of whatever instrument is connected to the input.

I redrew the schematic to make it easier (for me) to see what's going on:



In addition to working pretty much as advertised, the gain stage + VCA on it's own also works pretty nicely as a noise gate. Here's a video showing how the fuzz sounds on it's own and then going through the VCA. Then, around 3:45, I replace the fuzz part of the circuit with a send/return effects loop and play with the unit as a noise gate. Then, around 7:37, I try gating an atari punk console with a drum machine.

I thought it was kinda cool. Could probably be used as a building block in a number of different applications. So, there it is...

~ Charlie

[Gurner]

Just a quickie for the Brits   ...is R.A Penfold actually JR Hartley's cousin? ......I can envisage this chap ringing around various guitar/electronics workshops....."Oh hello, I'm looking for a schematic - It's called Fuzz Unit by R.A. Penfold"