Does any body now how to make an extremely simple octave pedal?

 

More specifically 1 octave down.

 

Well, just the PEDAL is simple. A normally open single-pole single-throw switch, connected to a 1/4" phono jack would do.

The trick is to re-map your instrument so that the sustain pedal input causes a 1-octave shift. This could take some fiddling around, and it may not even be possible unless you have a professional instrument.

You might be able to send the octave change command using a MIDI SYSEX, but that's not going to be simple, and would be instrument-dependent.

 

Does any body now how to make an extremely simple octave pedal?

I have seen these in electronics mags.

Basically amplify the signal first until it is upto TTl levels then pass it through a flip flop to divide by 2.

In the version I saw they allowed mixing of the original signal (amplified) with the new divided signal.

If your really brave do the same thing with a PIC micro but double and half the input frequency to get a nice fat sound.

 

OK, I'll plead ignorance then

Here's a link to a discussion elsewhere that looks rather promising:
http://electro-music.com/forum/viewtopic.php?t=15019

It links to this page:
http://www.robthefiddler.com/electronics-audio-diy/circuit-experiments/subripplerv1/
experiments with using a CMOS 4060 IC for a frequency divider.

I can't imagine getting any kind of fidelity through such a circuit, but you could wind up with interesting effects.
I received quite a few hits with this Google search:
http://www.google.com/search?q=octave+pedal+schematic
Some quite useful, many not.

This page has a good generalized description of a couple of different types of octavers:
http://www.bassplayer.com/story.aspx?content_id=24674
along with reviews of several commercial brands.

The A-D-A type might be programmed into a speedy PIC or other microcontroller. In this case, the hardware would be the easy part; the signal processing could get a bit dicey.