Circuit Skills: Perfboard Prototyping


Make Magazine contributor Collin Cunningham shows us how to use a perfboard to design a prototype guitar sound effect. Collin doesn't just make it fun but he makes it look easy.

Jameco sells Collins kit so you can play along at home. (2121092)




When you think "DIY electronics," one of the first images that likely comes to mind is of parts and wire soldered to a standard piece of perforated circuit board –– and that makes sense. Perfboard is widely used because it's so versatile. Essentially, it's just a grid of potential solder-point connections. You can trim it down to just the size you need, or leave extra space for future enhancements, or revisions, if need be.

In this latest installment of the Circuit Skills video series, I demo my own approach to perfboarding by building a rather unusual guitar effect –– the PWM, a design I found in Tim Escobedo's excellent Circuit Snippets collection.

(For those interested, I also drew up a more traditional version of the schematic – available here.)

In order to get this thing making sound ASAP, I omitted the stompbox switch and its somewhat complex wiring. However, the optional LFO add–on seemed a bit too good to pass up, so I did incorporate that into my build.

I knew from previous projects that the 40106 Schmitt Trigger IC could make some cool experimental synth sounds. It turns out that the chip also works as a surprisingly sweet distortion pedal, if you're into that tough & spazzy fuzz-bot kind of sound (which I am). If you need a boost getting started with your layout, here's a basic diagram of all the on–board connections I made (just much neater than how I actually made 'em)


Kit (2121092) Includes:

Part No.
Qty.
Description
24126
1
IC, LM386N-1, DIP-8
785071
1
IC, CD40106BCN, DIP-14
38360
1
Transistor, 2N3904, TO-92
51626
1
Socket, IC, DIP-8, Machine Tooled
37197
1
Socket, IC, DIP-14, Machine Tooled
35975
1
Diode, Silicon, Rectifier, 1N4001, 1A, 50V
691260
1
Resistor, 47KΩ, 1/4 Watt, 5%
691227
1
Resistor, 33KΩ, 1/4 Watt, 5%
93739
1
Capacitor, Electrolytic, Radial, 22μF, 50V
93731
1
Capacitor, Electrolytic, Radial, 2.2μF, 50V
29964
1
Capacitor, Electrolytic, Radial, 100μF, 50V
920510
1
Capacitor, Film, Radial, 0.1μF, 50V
15211
1
Capacitor, Ceramic, Radial, 0.0047μF, 50V
286222
1
Potentiometer, 500K, Linear, 16mm, 1/8 Watt
286206
1
Potentiometer, 10K, Linear, 16mm, 1/8 Watt
286572
1
Potentiometer, 100K, Audio, 16mm, 1/10 Watt
216452
1
Connector, 9V Battery, Safety Snap
281738
1
Connector, 1/4" Phone Jack, 2 Position, Solder Lug, Panel Mount
281746
1
Connector, 1/4" Phone Jack, 3 Position, Solder Lug, Panel Mount
105111
1
Protoboard, 2.4" x 3.4"