16 step sequencer

Designs used

MFOS 16 step analog sequencer MFOS Project Page
Front Panel express file Seq16Final.fpd NOTE Adjust fine tune pot holes to 0.2mm larger ones before manufacturing one.


Quite a lot of panel work to do on this one. Divided the panel PCBs into two parts, upper and lower to make assembly easier. Used 16 Alpha LED sliders for coarse CV adjust and 16 Aplha 9mm rotaries for fine adjust. Gate switches are dual LED NKK (GW-12 ILLUM) and they all shine red except for the active stage of the sequence. So when running, a green dot travels through the sea of red ones.

Wiring of panel PCB ongoing. Pin headers are used to ease things up. When finished there will be some 110 wires going to/from this board.

Front view. Shaeffer panel precision is immaculate, every slider, pot and switch operates smoothly

The PCB sandwich...

The top two PCBs are the MFOS sequencer boards, the one closest to the panel contains LED driver circuits and logic for the 2x8 // 16 step operation modes.

This is probably illegal in your country, but this simple hack allows for me to select 2x8 or 16-step operation. I combine two 4514s (4067 for digi board) into operating as one if I feed them the QD signal from the counter (16 step mode). If I instead feed them a 0 and 1 respectively (regardless of QD) they will run in parallel creating a 2x8 sequence with separate output stages.

Sequencer stopped. Control button green reading "START". Current active step is #1, indicated with slider #1 and gate switch button #1 is green. The reset button (big red one) is lit only when sequencer is at step #1.

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