Eight-step sequencer

December 2011

MATERIALS

  • 40106 oscillator
  • 4017 decade counter for ADC
  • 4040 ripple counter for ADC
  • LM311 voltage comparator for ADC
  • 4046 VCO
  • Bunch'o'LEDs and slider pots

(Or, “why bread-boarding is a good idea”)

This sequencer uses a poor-man’s resistor ladder combined with a comparator to serve as a note quantiser. Other than that, it’s just a basic eight-step sequencer that spits out a nasty square wave.

It mostly works, although:

  1. Resistor ladder based ADCs are fun to play with but a bit twitchy and a bit of a pain. Plus, most of my components and time spent was to build this - I’d have been better off using a dedicated analog to digital chip.
  2. Despite being too impatient for breadboarding much of the time, the associated photo with this post indicates why it’s probably not a silly idea with any non-trivial circuit…