Fonitronik VCP Sequencer
some time ago kind mr CJ Miller sent me some old EFM schematics to upload them to my site. one was the ADC flash, based on LED driver ICs (LM3915). i thought about the use for a ADC module for a modular synthesizer and came up with the idea of controlling the steps of a sequencer with it. but why use expensive or hard to get LM3914/15?

so i utilized an ADC0801 (or even 0804) for that purpose. this IC accepts 0V-5V input, so i put a simple manual CV processor in front, with two additional comparators to drive helpful indicator LEDs for voltages higher +5V or less than 0V.

the parallel output of the ADC gets converted to grey code and amplified to drive CMOS4016 switches. these switches turn on/off the outputs of a 4017. BTW each control input of the CMOS switches can manually switched between ON/OFF/ADC output to provide manual control of each step and to overwrite the ADC if necessary.

the actual sequencer section is a baby10, limited to 8 steps. the incoming clock gets ANDed with the sequencers steps out to provide a trigger output, which pulse width follows the incoming clock.
STATUS: built
here's the proto, side by side with the simple inverted divider proto.
for the prototype i had only red LEDs on hand - will have to replace them later...
Baby8 VCP Sequencer (proto)
i built a 1U stand alone unit too. i love it!
VCPS8 1U standalone
last update 11 JAN 2012
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