The Electronics Cranny: Make Your Own Fuzz Box
Apart from the usual tone knobs, there are at least three different electronic effects that are currently in vogue among individual guitar operators and pop groups. They are:
(a) Echo or Reverberation- effected by a tape delay or a mechanical delay. This is made evident as a periodic recurrence of a single sound.
(b) Vibrato– sometimes mistakenly called “The Patrick Lalime Pitch”- is produced by mixing a fixed low frequency oscillation with a signal from the guitar operator.
(c) Fuzz Box- a harsh yet not unpleasant sound effected by wave shaping circuits. The impact of this contrived distribution is more evident on low frequencies or if the Fuzz Box is placed near a sound-absorbing couch or sofa.
Here at The Electronics Cranny, we have seen several published designs for Echo Units and Vibrato Units but very few for Fuzz Box circuitry. “There is a tremendous interest in the Fuzz Box,” said noted guitar operator Tom Evenings, who performs in the “Lankville Hill Basin Style”. “Commercial units are available, of course, but usually they are cost-prohibitive and I know I speak for a number of guitar operators in noting that we would greatly appreciate a schematic on how to build one, perhaps from, you know, an Electronics magazine or something like that,” added Evenings.
Guess what Tom? Your friends at The Electronics Cranny are happy to oblige.
“Oh, great, thanks,” noted Evenings.
A long, odd silence ensued.
TECHNICAL DESCRIPTION
The Fuzz Box is based on a three stage shaping circuit (see figure one). The initial stage (marked with the first large vertical line in bold) is a simple pre-amplifier that can be found at any small electronics retailer or at one of those roadside stands. The value can be decreased to 0-1f if fuzz bass is not to be used or, again, if you put the Box near a heavy sofa.
The signal developed across the second stage (marked with the second large vertical line in bold) utilizes a semiconductor diode and can be reasonably applied for point contact, junction types and Paille Belts. The interspacial values are non-critical and a choice of resistor between 600 kilohm and whatever you’ve got lying around should prove satisfactory in the long run.
There are two more stages (marked by the third and fourth large vertical lines in bold) which both serve the by-passing of the effects box when the switch is not depressed and also the foot paddle. As can be seen, this provides a considerable saving in current.
CONSTRUCTION
Since the unit housing will be subjected to continuous foot pressure, it was decided to use an aluminium chassis, with the flux switch being mounted at one end. This allowed for easy control as the foot can pivot on the box or, if you don’t have any feet, can be operated with a long stick.
Assembly of components is made on a piece of Saffran Board and can be readily followed from the wiring diagram (see figure two). Fresh insulation or a similar substitute (cotton candy works well) should be used for the board mounting but in the prototype a section of barrier terminal strip must be attached quadrilaterally (see figure two).
EFFECTS SWITCHING
There are three possible methods for installing and using the switching unit.
(a) The unit can be installed in the amplifier itself with a series of manual controls to form a “fuzz cohort”.
(b) As the foot paddle. In this scenario, the guitar lead will plug directly into the paddle and the output from the unit will connect to the amplifier.
(c) As a component piece within a larger unit, either an electronics setup, a piece of furniture or inside a tree.
POWER SUPPLIES
There are a number of different ways of providing power to the Fuzz Box: batteries, mains driven power units, tapping of the foot paddle from the power amplifier, etc. Polarities, connections and a thorough numbering of the carts are very important. Batteries should present few problems, however they’re very boring to purchase. There is really nothing more boring than approaching a battery display. You can avoid this method by creating a circuit similar to those illustrated in both figures above.
Another method is to harness the power of the wind. This can be accomplished with a Zener Wind Diode and a schematic available in my pamphlet Wind Power and Electronics: A Probe available by mail for $1.95.
FINAL ANALYSIS
By now, your Fuzz Box will be powered by the wind (or batteries, if that’s how you want to live your life) and ready for use. Check your specifications one final time and then amaze your friends or heterosexual lovers with the brilliant, queer sound of fuzz. Return to the schematics for an occasional refresher.
LETTER SACK