Tuesday, September 28, 2010

DIY Stompboxes - Matsumin's ValveCaster

Here is a simple Tube Overdrive/Boost pedal that can be built in a weekend if you have enough materials laying around (or if you spent some time & money and sourced the materials commercially).

It is based on Matsumin's ValveCaster, which has plans and a discussion thread a mile long on DIYStompboxes.com. Unlike Tube Amplifiers, this is a simple 9-12 Volt circuit, and can be built for under $50 (not including tube). It sounds incredible between a guitar and both tube or solid-state amplifier. It is versatile enough design that you can incorporate other effects into the same pedal, or go beyond for more stages. Take a listen to one of these builds, courtesy Dovinia:

(I would post a video of my own, but I am still a n00b at playing the guitar. I have had more fun building this stuff, and watching the reactions of regular players who get a feel of the tone of this thing with their own playing.)

Here are a couple of more links with others builds of the same design:
Some sweet licks and tone on a one single tube
Not enough? Go for two stages of gain!
Or even more...here are 3 chained together

With enough love and care in the manufacturing process, you could have a world-class tube overdrive pedal that is completely unique in design, and sounds just as good as one of the expensive boutique tube-overdrive pedals out there. Here is what I created and painted in my garage last winter which I hope to post videos of soon:

The name just stuck...It's a 12AU7 tube pedal running with a starved plate (cold) at 9-12 volts, while the 12AU7's specifications are designed to operate at over 200 volts in an amp.


  1. Don't think I will be building one of those any time soon, but sounds interesting.

  2. You sir, have made an awesome pedal.

    How long does something like that take? Is it fragile? Can you burn it out? :)

  3. From the time I started drilling out the Hammond 1590B box...to the time I baked the last layer of Clearcoat, it took me most of a weekend, including soldering, assembly, and filing out the center of the tube socket to mount a blue LED.

    Sure the tube can be fragile, so I wouldn't advise kicking it. My second build has a protective rail on it so you can't step on or kick the tubes (I have a 2-tube pedal in the works, on the bench)

  4. How do you think it would sound on a bass guitar?

  5. i gotta show my brother this, he's the music one

  6. Did you learn to build all this by yourself?