Planning - Stage One

Good news, the parts arrived today (very rapid service from bitsbox), and before I check through them to see that all the parts I ordered are actually there, I'm going to think about the build ahead of me.

So I've got a circuit with stripboard layout from a chap called biffa who frequents freestompboxes.org - Thanks biffa! The next step is to decide on how the bits will all fit together in the box...

The stripboard holes are 0.1" (or 2.54mm) apart and there are 9 x 15 holes - This leads me to the conclusion that the board will be approximately one inch by just over one-an-a-half - That's tiny! There shouldn't be too many problems fitting it into the box. In fact, the Hammond enclosure I've got (110 x 60 x 30mm ish) should be able to accommodate the board lengthways OR transversely which gives me more options on where to run the wires. Longer term, I'm planning to build a short run of 10 or so of these pedals (if it sounds good) for various friends and a few to sell to cover the cost of building my own: For this future run I'm hoping to put the circuit in smaller 90 x 33 x 27mm enclosures to make a single knob "Microfuzz" pedal, but with this first prototype I'll have much more space to move the guts about in.

For the off-board wiring, I've used two diagrams to help me figure out how to hook it all up - This one from the excellent Beavis Audio site is the most visually pleasing and easy to read: I'm now confident about how to wire up the 3PDT. However, I've read various threads about true bypass switching options, and the word on the street is that higher gain circuits can sometimes hum when bypassed if the circuit input is not grounded when bypassed. Now, I don't know if that's likely to be the case for this pedal, but since there is no gain control on the one knob fuzz (it is effectively permanently maxed) it seems better to be safe than sorry. So after a bit of searching, I found this excellent 3D representation of stompbox power and 3PDT wiring which is also input-grounding.

NOTE this diagram only shows wiring for a DC power-only configuration: If you want to use battery power as well, you'll have to work out from Beavis's diagram where to intergrate the battery clip into this model. This isn't neccessary for me, as I don't need battery power for mine, and the Microfuzzes won't be able to fit a battery within the case anyway...

First proper build

I've decided, after a protracted but intermittent period of research, to build a Colorsound One Knob Fuzz guitar pedal. The criteria that guided my choice of circuit are -

1. As my first "proper" stompbox build, the circuit needed to be simple. I've made AB boxes, TB loopers and a couple of tap tempo switches, but they were all totally passive, so this one has to have as few parts to wrong as possible. A single volume knob, 12/15 components, a couple of jacks, a switch and 9v powering should be managable.

2. I don't want to mess around sourcing matched tranistors or testing them myself or endlessly swapping them out for different pairs to hear the diffence - this circuit is reputed to sound pretty good with a BC108 and BC109, which seem easy to come by.

3. The parts needs to be cheapish - This first build is really only a excercise to learn about building stompboxes: I have much grander plans to make a couple of boxes that you can't really get commercially, e.g. a Lovetone Meatball. You can pick up a cheap, basic fuzz for £30, so a cheap basic fuzz made by me as a practice attempt needs to cost a third of that or less.

My brother-in-law gave me the parts to build an AB box, so I've got the 3PDT, jacks, LED, power jack and battery holder, so the stripboard and components shouldn't come to more than £3.00ish. Next step - Sort the layout and look into grounded-input switching....