# Discovery: Analog octave up with Moogerfooger MF-102

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

1. ### 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

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

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

4. ### 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

Oct 1, 2003
Denton, TX
Oh, ok.

I think I get it. Thats a great explanation.

6. ### 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

7. ### 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 DeBordSupporting Member

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