interesting circuits

-minus- · Joined: Oct 26, 2008 Posts: 787 Audio files: 13

Finally have the cacophonator working. Redid my stripboard with a bit more room for the caps and followed the PCB on page 1 more closely. It now has a slightly bigger footprint but hey, it's working, and I'm happy at that! When I get a bit more time over the next few days I'll post the diagram incase anyone else wants to have a go.

Just a small thing: judging by the original schematic, I think the capacitor from pin 14 should be 0.01uF, not 0.1uF ... not that this may make that much difference.

-minus- · Joined: Oct 26, 2008 Posts: 787 Audio files: 13

Just thought I'd let you know that I have posted the diagrams for a strip board version of the Cacophonator here:

http://electro-music.com/forum/viewtopic.php?highlight=cacophonator&t=40593

Also, here is a new link to Art Harrison's site. It has changed for the one listed earlier:

http://theremin.us/

clairvib · Joined: Apr 10, 2011 Posts: 3 Location: Boston, MA

Carlox or Minus,

You've both built the cacophonator 2 (with input) from a schematic... ...The links to this schematic seem to all be broken. Can anyone who has built one upload the schematic? or perhaps a stripboard design for it?

Based on the discussion in a different thread, the general idea is straight forward, but some details are missing.

The idea: An input signal is brought in through a 4049 hex buffer so its voltage is in the correct range, and also so that it can interact properly with the other oscillators - by coupling through the ground. The output from this 4049 needs to be summed with the oscillator signals, so it likely is added through a 10k resistor to the outputs of oscillators U1A, U1B, U1C, U1D (pins 2,4,6 & 8 ).

This new circuit with input substituted 15k ohm resistors for some of the 10k ohm resistors, for some reason.

This circuit also added four new on-off-on switches and had some doubled capacitor numbers. I.E. 3x C3, 2x C4, 2x C6 and 2x C11. The extra switches likely switch between different timing capacitors for some of the oscillators, and the off position of the switch likely stops some of the oscillators from oscillating.

If anyone can confirm if some of these educated guesses are correct, or even better - repost the schematic, that'd be great!

-Clair

6581r4AR · Joined: Apr 03, 2011 Posts: 15 Location: Texas, USA