Externally modulated effects..????

[Skidood]

I have thought up a novel way to provide a variable input (voltage) which would be easily controlled by the guitarists foot, and no, it's not a rocking pedal. This is easier to use.
I'd love to try this idea out maybe  on a phaser or flanger.
Can anyone recommend a DIY project that utilizes an external control voltage to modulate or otherwise control the effect?
If this works out, I will definitely be posting plans and schematics.

Andy

[cd]

Use your variable control voltage to vary the brightness of an LED, which then is attached to an LDR.  Then use that LDR in place of whatever pot is doing the control you want to vary.  Obviously, will work best with rheostat type-controls (especially LFOs), and may need some more tweaking for voltage divider type controls.

[octafish]

Try the Phungcosis in Tim E.'s Circuit Snippets. I havent built it myself but the sound clips sound cool. Plus there is an aux CV in already drawn in.

[Processaurus]

If you have any interest in wah wah type sounds, any auto wah circuit uses a voltage controlled filter to make the wah.  It would be easy to ommit the envelope follower part of the circuit and make your expression voltage control the sweep of the filter.
Also a simple volume control would be great, for manual tremolo and swell effects.  Check out this guy's page about the Craig Anderton volume pedal de-scratcher:
http://www.diyguitarist.com/DIYStompboxes/Vol-Pedal-Retro.htm

it turns a scratchy volume pedal's pot into a voltage control, which goes to control a volume circuit.  Sub in your control voltage instead of the pot, and you're there.

I'm really interested in alternatives to rocker pedals for controlling musical effects (like the zvex theremin stuff, photo cells, and that roland dbeam thing, as well as Paul Perry's Space Beam), so if you get something going, I'd love to hear about it.

[Mark Hammer]

a) Take a look at the Patch of Shades pedal, shown over at tonefrenzy (http://www.tonefrenzy.com/effects/stick_enterprises_patch_of_shade.html) for a somewhat different approach to external foot-modulation.

b) Take a look at the Technology of Autowahs article I have posted at my site (hammer.ampage.org) for a discussion of how to adapt the lowly Doctor Q (which logically extends to the Doctor Quack and Nurse Quacky) to external control.  The DQ is about as ready as they come.

c) Take a look at about a dozen of Tim Escobedo's various filter-related projects at circuitsnippets for other ideas.

d) Take a look at the various articles in the AMS-100 series in DEVICE (also at hammer.ampage.org)

e) Smile....broadly....when you get it working.