Octave down pedal

Discussion in 'General Electronics Chat' started by MDK, May 12, 2008.

  1. MDK

    Thread Starter Member

    Feb 1, 2008
    22
    0
    Does any body now how to make an extremely simple octave pedal?
     
  2. MDK

    Thread Starter Member

    Feb 1, 2008
    22
    0
    More specifically 1 octave down.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    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.
     
  4. nigelwright7557

    Senior Member

    May 10, 2008
    487
    71
    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.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    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.
     
Loading...