Cacophonator Strip Board

dylar · Joined: Apr 25, 2011 Posts: 47 Location: iowa

So no one has come up with a working schematic for the input jack yet? PLEASE someone help...

elmegil · Posted: Sat Feb 09, 2013 12:12 am Post subject:

I built the basic cacophonator circuit over the last hour (sounds really cool), and I will work on the audio input some time tomorrow or Sunday.

One thing I noticed that may be important--I haven't read this thread in detail, but I was thinking I needed to use a 4069 for the audio input, as that seemed to be the main thing people were talking about where I was skimming. However, the circuit diagram from page 4 uses a 4049, which has a very different pinout... I would guess if you used a 4069 but connected the pins as shown in the schematic, things would not go well for the audio input. I will try both (with appropriate pin changes) and see if one does better than the other.

One other difference in mine is that I'm using a 15V bench supply rather than a 9V battery for power, but for the basic circuit that doesn't seem to make a lot of difference.

elmegil · Posted: Sat Feb 09, 2013 9:17 am Post subject:

Built the audio in, heard no effect. Shifted my jack to before C13, and BARELY heard my audio--my input is a smartphone because I'm monitoring through my computer.

I believe I need some amplification of my source signal before this might work, not sure if that's relevant to anyone who was working on this before or not. I'm going to set up a little LM386 pre amp stage and see if that works any better.

dylar · Joined: Apr 25, 2011 Posts: 47 Location: iowa

Thanks for the effort! Excited to hear about your results.

elmegil · Posted: Sun Feb 10, 2013 12:39 pm Post subject:

Amplification does get the signal through, but it doesn't sound to me like the video, it just basically mixes the audio through. No variable distortion, it's either there and competing with the oscillators, or it's not. The frequency of the oscillators/starvation of the circuit are the only things that affect how much distortion there is on the signal, not gain on the LM386, and not the pot on either the 4069 or Oscillator 4 (where it gets injected).

If anyone else wants to try it, I used the amp circuit from here:

http://www.fluxmonkey.com/electronoize/386amplifier.htm

dylar · Joined: Apr 25, 2011 Posts: 47 Location: iowa

I'm getting suspicious about the whole project. As far as I can tell the only video of a Cacophonator that actually processes a signal is the Sascha Neudeck one. There are two other versions with inputs, neither of which actually distorts the signal (or if it does it's very subtle):
http://youtu.be/11ObmwNxL7U
http://youtu.be/zURxDI_QQHk
After watching Neudeck's video again I think I know what is going on. First, there are two extra knobs on his. I'm guessing he added a simple LP filter (and maybe something else) in between the audio input and the output. When he's turning the two knobs on the bottom left he's operating the added effects. The other knobs just seem to adjust the normal cacophonator squeal. When you have the noise made by the cacophonator along with and input signal that passes through a filter and maybe distortion circuit then you'd get sounds like you get in his video. It's possible that the cacophonator also passes through the filter--I can't tell. Maybe the second mystery knob adjusts the input level or else a distortion level. Here's his video:
http://www.youtube.com/watch?v=q_s4U-8V2Gg&feature=share&list=PL416C4854F84E5312
It's actually pretty brilliant. It probably doesn't work too well with guitar.

synthesist · Posted: Fri Feb 15, 2013 11:34 am Post subject:

After some problems I finally build some versions with working input.
But I never kept the circuit on breadboard cause it didnt sound good enough.

The best result I ever had was to play the output of the atari punk console into Pin 14 without any amplification. It worked like one could use the cacophonator like an broken equalizer distortion resonator. really cool.

I am sure the input has to be only Pin 14 where the chip gets it voltage. Otherwise I think u would destroy the unit. If the chip doestnt get enough voltage but the inverters do ( because of the high amplificatioon) it is supposed to die!

U guyes should filter the amplified output before it goes to pin 14. Just try different capacitors against ground. This makes it sound better.

goog luck
xonrad

Familiar · Joined: May 14, 2013 Posts: 1 Location: Barcelona

Hi Everyone!

This is my first post over here. Just saw the link to the schematic by chance. Iḿ glad it has been usefull for someone Very Happy

See a couple of videos of cacophonatro 6DE (Circuit from famfest.info) working with audio inputs:

Quad-T from Befaco (808 conga clone)

http://www.youtube.com/watch?v=j-sNBo5fZ24

Stylophone:

http://www.youtube.com/watch?v=sSxiDPyuJ1I

Buddah machine v2:

https://www.youtube.com/watch?v=4s8xdxX-z1E