Thursday, December 22, 2011

cd4046 as Pitch Tracker

I have been experimenting more with the 4046 PLL chip after finding some great projects in Nic Collins' book, "Handmade Electronic Music":

I adjusted some of the values in the schematic to utilize the parts I had on hand. I also removed the 4049 gain circuit used in Collins' design.  It had minimal effect in my Lunetta and there's no need to use it unless you are trying to square up the incoming signal; like from an electric guitar.

SpaceNuts by Draal

Galaxian by Draal
In the tracks above, I fed it the output of my 4052 module (4 inputs where A and B select which input is 'on').  SpaceNuts uses a 22n cap while Galaxian uses a 1uF cap.  The larger cap doesn't track as acurately as the smaller one,  but does offer a great "dive bomber" effect!  Having a switch to choose between two caps like this sounds like a fun idea.

Updated version for Lunetta Use
The effect is quite nice; turning barely audible clicks into a richer pitch making endeavor.

Tuesday, December 20, 2011

A Rather Unique Mixer: a 4X4 Matrix Mixer to Be Exact!

Tired of your run of the mill mixer for your creative endeavors?  Then please have a look at my friend, concretedog's beast.   Here is a shot of the schematic from his November 2010 archives:

MATRIX01 by concretedog
Head over to his excellent site for more of his experiments as well as checking out his awesome music he's making.

4051 CV Generator Module

The 4051 is an analog multiplexer otherwise known as a digitally controlled analog switch.  Three controllers, A, B and C decide which of the 8 channels turn 'on', making it perfect for lunetta use.  You can simply wire the ins and outs to a panel and connect them to the other  modules in your machine and be quite happy.

But I want to show you how to make something even cooler: The 4051 CV Gen.  It's a variant of the 1 Bit Custom Waveform Generator posted here.  I used individual SPST switches instead of the DIP switch idea and I brought AB and C of the 4051 out to the panel to make em' patchable of course.  Big shout out to RFeng over at the "forums" for his suggestions!
Inside 0ut by Draal

 The recording above was done live straight to my Ipad and recorded with the Soundcloud app.

Connect a few oscillators to the AB and C controllers, adjust their respective speeds, and flip a few switches until you are pleased.  Then mix it up by substituting one or more of the oscillators with the outs from some of your other modules.

Tuesday, December 13, 2011

The 4015 Shift Register Continues to Surprise

While experimenting with the fun 4018, I decided to unplug all the various gates and oscillators and start fresh. I asked myself what else haven't I tried connecting to those Jam inputs? Then it dawned on me that I could use 4 outs from one half of my 4015 shift register.

Results: Awesomeness.  Awesome in its simplicity.  I have 2 oscillators going into the clock and data pins of the 4015. I connect the 4 outs into the jam inputs of the 4018. It also has clock and data pins connected to 2 oscillators. Output this to your mixer/amp and tweak to your heart's content.

More on the cd4018

By connecting some of the outs of a 4017 counter to the jam inputs of the 4018, you can get some very interesting patterns quite easily.  My setup for this track:
  • 1 oscillator to clock the 4017
  • 2 oscillators for the Clock and Data inputs of the 4018
  • 5 outs from the 4017 (pins 3,2,4,7 and 10)
  • Pin 1of the 4017 is connected to the Reset pin of the counter
  • Pin 13 of the 4017 is tied to ground; pin12 no connection
There is the addition of the 4040 and 4052 to add some texture to this track.

This track uses a modded Danelectro Slapback Delay pedal which then goes out to my Vox Pathfinder amp, and then Line Out to my Mac running Audacity.

Here's is a stripped down example of the 4017 and 4018 without any other cmos action other than clock and data sources for the 2 ics.

Sunday, December 11, 2011

Using the 4093 as PWM Part 2

Here's an example of the PWM with an added LFO into pin 4 of the 4093.  The addition of the LFO, or any slow oscillator into the PWM creates plenty of sonic mayhem to experiment with.  The PWM circuit will work perfectly fine without the added modulation in your lunetta however, bringing an input jack from pin 4 of the 4093 to the panel is easy enough to do.

Thursday, December 8, 2011

Guitar or Mic Input: Draal's Take on the PWM

I found a great and simple circuit for making a guitar signal "square" and thought it would work in my lunetta.  It's based off of Tim Escobedo's PWM and I used parts I had on hand.  I used a 4093 instead of a 40106 and I also replaced the 500k pot with a 100k.  The .005 cap was replaced with a .0047 as well.  No need for the DPDT switching:  Just run a banana jack to pin 3 of the 386 and your out jack right after the .1uF cap on you cmos chip.


You can add the LFO that's shown in the layout if you want to take advantage of the unused pins of the 40106.  This clip doe not have an LFO modulating the effect.  I will demonstrate that addition soon!

Why all the excitement?  Well, how about using a guitar, keyboard, or circuit bent toy to add some interesting sounds to the mix?  I like using a mic to add vocals to my sessions as well as to provide pulses to "clock" other modules. The Pulse Width pot helps find that sweet spot to trigger other modules.

It works very well as a clock source for the 4040 for example and offers a simple way to create a sense of randomness in our jam sessions.  You could for instance, place a sensitive mic near the dishwasher or open the window when the garbage truck comes, smash around some pans....

From Tim Escobedo's Circuit Snippets

You get the idea.  This module has a ton of versatility in bringing other instruments into the experience as well as providing a pulses to manipulate other ics.  Try it!

Wednesday, December 7, 2011

The 4018 Divide By 'N' Counter

Here's a track featuring the 4018

I like this chip. The cd4018 is a Divide By 'N' counter in which you can preset how it divides: by 2, 3, 4, 5, 7, 8, 9, etc.  For even numbers, you're just connecting one of the Q outs back to the Data input.  For odd number of divisions, you're adding another cmos chip into the mix; the 4011.  The data sheet will help you figure out the right count you are after.  Study it :).

For my purposes, I tend to use the Jam inputs instead of just connecting a Q back into the Data slot.  I connect oscillators or outs from my gates to the Jam Inputs to get some nice patterns out of this chip.  Output can be any of the Q's:  each one may sound a bit different so let your ears decide.
  • 1 Clock input
  • 1 Data input
  • 1 Preset Enable Input (I tie High to use the Jams)
  • 1 Reset (Put on a switch or bring out to a jack to disrupt/change/gate the data flow)

All the above ingredients spell for fun times in our lunettas.  All those outs from our other chips are looking to party and chips like the 4018  are the "meeting grounds".

There will be Noise: Lunetta Jam 01

Here is a spur of the moment jam using a few oscillators to control other modules.  It shows how much of a racket you can get by mixing ;).

One oscillator goes to my divider (cd4040).  A number of outs from the divider go into a couple of 4011 gates.  The outs of the gates go to the ins of the 4052.  Two more oscillators go to the A and B controllers on the 4052.  Those inputs will determine which of the 4 channels on my 4052 gets heard.  That output goes to one of the mixer's 4 inputs.

I also have some outs from other ics going into my resistor ladder and that goes to a separate mixer input.  So I'm able to have two different sounding outputs that I can bring in or out of the mix.
Here's the video:

Saturday, December 3, 2011

Adding Effects to the Lunetta

One of the most satisfying feelings comes when you have a few modules under your belt and you start recording or jamming with your new 'instrument".  Even more satisfying, is when you start adding effects to the mix.  Enter effects pedals!

What works well with our machines:
  • Delay/Reverb
  • Phasors
  • Chorus
  • Tremolo

Overdrive, fuzz, and distortion pedals often have a less noticeable vibe at the output in my tests but your mileage may vary.  I have had some success using a fuzz to square up a weak signal;  a current project that involves mic input is calling me back to the bread board!

One of my favorite pedals is delay.  This type of effect really open up the possibilites in how you "play" your lunetta.  When looking for one, look for long delay times or at least one that can be modded to give longer repeats.

My second choice is my trusty MXR Phase 90.  The best way I can describe it: chewy!  Seriously, this effect adds a ton of character to these square waves.

Thirdly, a wah wah pedal is essentially a bandpass filter that's adjustable with your foot of course.  Sweeping from low to high easily allows for more expression during jam sessions.  Extra bonus points:  we don't have to dig into a lot of theory to achieve filtering effects.  ( We'll discuss some simple voltage controlled filter concepts in the near future though).

Sound samples:

With delay:

With phasor:

With wah wah pedal:

Thursday, December 1, 2011

Build 4 Oscillators Out of a 4093

Besides the 40106, we can make a set of 4 oscillators using the 4093 ic.   We just tie one of the inputs on each trigger to power.  Or you can set up a chain where Oscillator A triggers Oscillator B when A's output brings one of B's inputs High.

A switch works great too;  just wire a SPST switch between power and input 1 in this example.  If you had a momentary switch, you can "play" or gate each oscillator to your liking.

A number of people have built "nand synths" around this principle.  When you're done with your lunetta, you will have 10 times the mojo ;)!

4093 Pinout