What's the BassAce?

The BassAce is a circuit board that was available from Tom Gamble at EFM.  It's a MIDI controlled monosynth that has a lot of the personality of a TB-303.   It has a single saw or pulse VCO,  AD/AR envelope generator and a Moog-Style lowpass VCF.  Also available are mod wheel (or pitch bend with a modification), slide and accent.  The BassAce "kit" comes with a circuit board, pre-programmed PIC and a few hard to find items;  You must provide an enclosure and 95% of the components.  Since you must provide your own parts, the BassAce lends itself very nicely to modification and experimentation.  My BassAce is currently unfinished, but I'm going to begin assembling my modification ideas here so I can discuss them with other BassAce builders.  I will lose a lot of the 303 charm and simplicity, but I'll gain a lot of new tonal possibilities in the process.  Since the 303 is a little over-used in electronic music, the extra flexibility will be welcome.

 

Project Status:

I began working on my BassAce about a year ago. I used an aluminum cigar box for the enclosure, which is finished except for panel labels. I've also fully populated the circuit board and completed about 75% of the front panel wiring. I tested the MIDI interface, and it seems to be outputting both pitch CV and gates properly. As of yet, the oscillator is not...well...oscillating. It's quite possible that I have just miswired something, or perhaps it's not working because all of the panel wiring isn't finished. I got a little frustrated and set it aside for the time being. I hope to return to it soon.

While I was building the BassAce I did toss in a few modifications. I added a mixer, instead of using the Saw/Pulse switch. I've also added a second pulse shaping circuit. This allows me to change the pulse width without screwing up the suboctave divider. If you don't do this mod, you are stuck with 50% pulse width