Thursday, May 30, 2013

Rick Moranis 10 Step Baby Gate Sequencer module based on the CD4017

I Just finished my newest version of the "baby 10 sequencer".  It has control voltage and gate switches.  I found some problems with it, and subsequently this module.  I will be posting some modifications in the next few days. 

In preparation of improving my baby 10 sequencer, I've been coming up with things to do with the CD4017.  A couple weeks ago I built the sub-oscillator out of the CD4017.  That introduced me to the 2 transistor Schmitt Tigger which I borrowed from the Yusynth clock divider.  I also borrowed from that same clock divider, a diode "and" gate which I modified for this project.  I also chose to incorporate a "gate to trigger" circuit similar to Ken Stones Gate to tigger circuit for my reset sync input.  I'm not sure how much of this module you could actually call mine, but I guess this is how you learn at first.  Working out this circuit will be a big help when I move onto my all encompassing 10 step baby sequencer.  possibly my next project.

I did a mock up on a breadboard of my idea to make sure they would work.  here is a video.

Monday, May 20, 2013

Square wave sub oscillator based on the CD4017

Wouldn't it be cool, to be able to mix in different sub-octaves of a frequency, similar to an organ or my old Korg poly800, without using up a bunch of oscillators?  NOW YOU CAN! This module is in the realm of wave folders and saw tooth animators.  an oscillator augmenter.
I got an idea of how to do that with the CD4017 when I was looking up schematics for building a Gate sequencer and a clock divider.
Essentially,  how the module works is, you feed it a very high frequency from an oscillator.  it creates a square wave version of the original signal and the 3 octaves bellow it.  you can access any of the signals directly, or mix them via potentiometers to a mixed output jack.

Below is a schematic I drew up that shows the basic idea.  This schematic only shows one sub-octave, not all three.