A great little OD!
This is my Boss OD-1 build. I used parts I already had around, so it differs somewhat from the straight Aion build instructions. All values are identical to Kevin’s build instructions, however. The enclosure is a little bigger, the jacks are oriented differently and the pots and switches aren’t board mounted. The only part I didn’t already have was the RC3403 chip. The big Mylar caps I used almost didn’t fit in some spaces. I’d go with the smaller Panasonic caps if you are ordering your parts for this project.
This was a smooth build the whole way through and the pedal worked perfectly the first time I plugged it in. It sounds fantastic; nice, smooth and fluid tone with a little bite to it. I used MOSFET’s for the other clipping section and they sound maybe a little more saturated and “rounder” than the stock diodes. The second switch is great for adding low end and fullness and sounds especially good, IMO, when used with the neck pickup (single coil or humbucker) and the drive knob at or near max. This gives you a beautiful, fat, sustaining tone for leads. With the stock asymmetrical diode arrangement, the mod switch off and drive knob set at noon or higher, this thing just exudes classic rock rhythm tones when playing on the bridge pickup, especially with a humbucker. A keeper!
Modifications or part substitutions
No mods other than the clipping and bass mod switches that are already included in the build, if you decide to add them. I recommend including them since they add to the pedal’s versatility and the solder pads are already included.