Sequencers take synths to new levels. They can even make simple oscillators useful and rhythmic sounding. After spending some considerable time designing the interface for my 6 channel programmable analog sequencer I decided to go ahead with cutting and populating of the aluminum face plate. The finished product ended up resembling a synth module which can be loaded into a case and populated with other modules. However creating a 16 step programmable analog sequencer would take quite an effort considering each channel would need 16 knobs, unless some clever memory banking is used, still such a build can take days to complete and cost a lot of money mainly sunk into Potentiometers and switches.
The cardboard prototype posted earlier was an attempt at creating a minimal but practical instrument. With 2 knobs, 6 buttons, and 10 LEDs this design is simple. The assembly can take at most a couple of hours with the right parts and it is hard to screw up. Future versions may even require fewer components, utilizing multiple modes for each control. Built around a programmable I/O board running a custom sequencer program makes the unit extremely flexible. The software can be upgraded to include algorithmic voltage generating functions. The intent of this particular sequencer was to have a light control source which can be used to play optical theremins or any other photo resistor devices. Utilizing a principle of Vactrol control the controlled devices do not have to be grounded or voltage matched in any way. Everything works out nice and easy. The amount of light emitted from a given channel and a given beat can be adjusted by the control knob and once the sequence is tweaked with desirable light amounts it can be played back in a loop fashion at any tempo. More info on the construction of this device will be available in a document form very soon along with source code.