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Discovery: Analog octave up with Moogerfooger MF-102

Discussion in 'Effects [BG]' started by psi, Nov 16, 2005.


  1. psi

    psi

    Mar 11, 2005
    New Jersey
    By mirroring your signal into the "Audio In" and "Carrier In" inputs on a Moogerfooger MF-102, an analog octave up effect is achieved. It's very different sounding from digital octave up effects that we've all heard, and it's almost closer to a tonal change than a pitch change.

    Scientifically, the frequency is multiplied by itself in this fashion, producing a wave exactly 1 octave higher.

    Audio clip
    clean arpeggio
    octave-up arpeggio
    clean chord
    octave-up chord
    more octave-up chords, sounds like guitar-like
     
  2. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Cool. Thanks.

    I like that effect; it's more subltle than I'm used to thinking of modulators like that.

    Joe
     
  3. Sonorous

    Sonorous

    Oct 1, 2003
    Denton, TX
    I thought an octave was the frequency doubled, not squared?
     
  4. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    What's being squared is the instantanious voltage. This is not the same as 'squaring the frequency'.

    For a pure sine wave, squaring the voltage does result in another sine at twice the frequency - plus a D.C. component.

    Anything other than a pure, single-frequency sine results in much more complex waveforms that include sum and difference frequencies of each harmonic component, with each other component. In the case of squaring like this, many of the mathmatical 'differences' show up as D.C. (zero Hertz; each component minus-itself).

    This is an interesting subject to me. The classic
    analog 'octave-ups' always include some kind of 'modulator' in their circuit, don't they?

    Joe
     
  5. Sonorous

    Sonorous

    Oct 1, 2003
    Denton, TX
    Oh, ok.

    I think I get it. Thats a great explanation.
     
  6. spidersbass

    spidersbass

    Nov 29, 2004
    Downtown L.A.
    dont' forget, squaring the cosine plus its negative waveform tangent cubed produces an equally powerful D.C. voltage as mirrored through a harmonic squared sine but will eventually produce a heat shield over its components far to great to be measured in even Kilohertz, thus making it possible for bass players to play Roundabout with a wooden spatula all while fighting invisible ninjas :p
     
  7. elros

    elros

    Apr 24, 2004
    Norway
    Proprietor, Helland Musikk Teknologi
    :)

    And all the rest of whom for which to whensonever of
    partially indeterminate bio-chemical degredation. Seek the
    path to the sudsy yellow nozzle of
    their foaming nocturnal parametric digital whole-wheat
    inter-faith geo-thermal terpsichorean ejectamenta.

    --
    From board tape at Zappa concert, outdoors, at Blossom Music Center, Akron, Ohio, summer 1984. This quote was in the middle of a spoken section of "The Mud Club" in which a dude walks into the club with a blue Mohawk and proceeds to "work the floor, work the wall, work the monitor system. . . ." The band was having monitor feedback problems at the Blossom concert, and there are numerous references to P.A. equipment throughout this ramble. Other than that, the quote is meaningless, I guess. But great imagery!

    http://www.science.uva.nl/~robbert/zappa/quote/
     
  8. Zane DeBord

    Zane DeBord Supporting Member

    Nov 23, 2014
    Brubeck Institute
    Reviving a thread to see if anyone can post some sound samples with working links!