The Valve Caster is a boost and overdrive designed to use a 12AU7 valve and run from a 9v battery (but I’ve found it sounds best running on 12v). It was designed by a guy called Matsumin and then developed further by Beavis Audio. Check out the Beavis Audio page about it here and read the thread on diystompboxes here.
The design I liked the most was the one with no tone control:
It’s a very full and warm sounding overdrive, and fairly simple to build as most of the circuit can be built on the back of the tube socket!
The values I used are as follows:
- R1: 1MΩ
- R2: 220kΩ
- R3: 100kΩ
- R4: 470kΩ
- C1: 47nF
- C2: 47nF
- C3: 1uF
- Gain: B50kΩ
- Volume: A100kΩ
- V1: 12AU7
Here it is all put together. I pop-riveted the valve socket in and then stamped the labels into the metal, which bent it a bit, but I think it looks kinda cool.
I built two of these from February to April of 2012.