The Dirty Bird’s roots are in the DIY stompbox community. Much thanks goes out to all the great folks at Aron’s Stompbox Forum. In addition, Lastgasp Art Laboratories is also greatly thanked and very much admired for the very cool Rattle Crow, which was the Dirty Bird’s original initial inspiration. With some redesign, modifications, changed component values and a few extra switches and things, the Dirty Bird can produce an extremely wide range of sickening, stuttering, fuzzy, distorted, noises and effects.

Schematic GIF
Layout GIF

The two switches for Q and Flutter could be 3-position rotary switches, but I used toggle switches instead, because I wanted to fit everything into a small 1590B enclosure. So, for the Flutter switch, I used a 3-position (center-off) DPDT toggle switch, shown as sw3a and sw3b in the schematic. For the Q switch, I used a 3-position (center-off) SPDT toggle switch, shown as sw4.

For the Q switch, the resistor values shown in the schematic will be pretty good if a SP3T rotary switch is used. But, I used different values to get the same result with a 3-position toggle switch. I put a 2M7 resistor on the center pole of a SPDT, and 1M5 and 560K resistors on the outside throws. That way, with the switch in the center position, the resistance thru the switch is 2M7. And, when it’s in either the fully up or fully down position, the value of the resistors in parallel will approximately add up to the other two values shown in the schematic.

Of course, one of the stompswitches is for bypass. The other one is called Chirp, and is shown in the schematic as the momentary switch (sw2) between the base and collector of the transistor. Stepping on it changes the character of the fuzz, making it less stuttery with some settings, and more piercing sounding with other settings. A regular on/off stompswitch, instead of a momentary one, would probably be cool, too.