DRAWING

Back To Top

Discription

This is really DBopII. I built the first one after I destroyed my Korg Minipop in 1985. At the time it was the only way I had to get a beat on my 4 track. When it died I was frantic to get a beat somehow and I remembered a series of articles in my collection of 1979 Radio Electronics by James J. Barbarello on the PerSyn percussion synthesizer.

Initial experiments were promising but I hated the sound of his tone generators. A friend had a Radio Shack beat-box that I thought sounded great so after a little reverse engineering I built generators that worked well enough to start construction. The first version had only kick and snare but four programs instead of two. It was a real mistake not to include a hi-hat and now that analog beat boxes are in again I thought it would be cool to do a updated version.

The generators can be compared in sound to the 808. I have always loved the sounds but they fell out of favor when sample based machines became cheap enough to own. Now I use my sampler to cop riffs from this thing. Funny isn't it.

The concept here was a programmable beat-box to create analog riffs with. I wanted it small, battery operated, cheap and easily programmed. There are a lot of drawbacks to the way this was designed formost is probibly eight beat resolution. Sixteen and thirtytwo beat resolutions can be simulated by turning the rate up. If you want to modify this I have included a schematic of a true sixteen beat sequencer but it can be carried even futher to the extremes see the section on modifications.

Programming

VIEW

Back To Top Back To Top

SEQUENCER

Straight out of those PerSyn articles in Radio Electronics. I used a electronic switch (the "CMOS Cookbook") to supply the hi/lo voltage to start/stop the clock driving the counter. The counter counts from 0 to 7 and resets. The clock also gates the 4081 AND gates making sure the output goes off before turning on again. I think the original article used 4011 NAND gates and then 4049 inverters.


Back To Top

ELECTRONIC SWITCHES


Back To Top

MIXER AMP


Back To Top

HI-HAT & SNARE NOISE


Back To Top

PATTERN SWITCH


Back To Top

SNARE & KICK GENERATORS


Back To Top

PCB-1


Back To Top

PCB-2


Back To Top

PCB View


Back To Top