Harmonically Related Ring-Mod?

[Jaicen_solo]

Just wondering about how this would work really. I was reading up Gez's thread regarding a string pluck generator, and I noticed something about feeding a divided down signal as a carrier for a ring mod. This got me thinking, if I was to use the octave down or interval signals from a Roctave, modulated against the clean guitar signal, would the resultant harmonics be musical?
Has anybody done anything like this?

[Mark Hammer]

I don't think it would be as useful as you hope.  Why?  Because ring modulation is arithmetic in nature.  It adds and subtracts blindly, without regard to whether any interval relationship is preserved.

For example, suppose I take a 500hz tone and octave divide it.  An octave below is 250hz.  So far, so good.  A 500hz tone modulated by 250hz gets me a difference output of 250hz (500 minus 250) and a sum output of 750hz.  Do the same thing for 1000hz and the difference and sum are 500hz and 1500hz.  Of course, you've already got the octave down, so that's no big help.  Is a 3:2 ratio of the sum useful?  You decide.

The other thing about ring mods is that they were developed using pure sinusoidal waveforms, and all projections of frequency content of the output are predicated on those pure waveforms.  What you get from an octave divider is anything but.  You end up with the fundamental being modulated by the harmonics of the octave down as well...and...that...ain't....pretty.  If you can successfully filter the extracted octave down, then maybe you can end up with a more pleasingly pitched-sounding modulation output.  If it can track the fundamental up and down, that's a good thing too, and I suppose it counts as being more "musical' than a conventional fixed modulation-tone RM.

[Jaicen_solo]

More musical is perhaps not the best term to use when describing Ring mod's (actually, i'm talking balanced modulators, but who's counting).
I was just thinking that perhaps it would lend some harmonic overtones that could sound good for more than special effects.

[Mark Hammer]

Look around for Robert Penfolds "Light Metal" project; a tracking ring modulator.

[Processaurus]

I wonder what is happening when you find "the note" on your ring mod that sounds harmonic with a note you play on guitar.  Is it the carrier being a harmony of the note you play?  An octave?  A fifth?  All the above?  It would definitely be desirable to make that relationship (whatever it is) track what you play.  Someone here had reported good results with running the dry and wet outputs of their whammy pedal into the two inputs on their (AD633 based?) ring modulator.  Though to get the right dynamics, you want to super compress/limit the carrier to keep it at a constant amplitude, so that it sustains properly.


http://www.diystompboxes.com/smfforum/index.php?topic=57080.msg443715#msg443715

A harmonically tracking ring mod would be very cool with a blend knob, you could use it as a unique, modern sounding distortion/degradation to your sound.

Doing it the bonehead way, I've had a lot of fun with a ring mod with an expression pedal, where you can set the minimum and maximum setting, to get the note right in one chord, and then sweep it forward for another.  Hopefully it will sound weird enough people won't notice there are only two chords in the part!

[jrc4558]

I've been on the similar quest, but nothing came out of it. What I ended up doing is taking the 555 section of John HOllis's Crash Synch (an awesome cirquit in its own right) and replaced the input section with just a clean x20 booster.