Adding expression

[leonhendrix]

I want to use my EZ vibe with my expression pedal to control the speed. I thought shouldn't be to hard i'll just read this:

http://www.geofex.com/Article_Folders/xprnped.htm

But it went on to say this (which applies to the easyvibe):  There is a third possible hookup for a speed control in the pedal that uses all three pot terminals but the third terminal does not go to ground. That would be more difficult, and we'd have to use the "advanced" method of controlling the effect - an LED/LDR variable.

I take it this is the LED/LDR method that can be used to do this?  (also found on geofex)

http://www.geofex.com/circuits/ldrlfo.htm

So is this the only simple method of adding a speed pedal to an easyvibe? cos John Hollis confused me by saying (in the easyvibe FAQs) "Add a pair of break jacks to the LFO rate control so you can use a volume pedal to control the speed" , which seems like it cant be done with adding an LED/LDR module.

confuzzled ?

[petemoore]

So is this the only simple method of adding a speed pedal to an easyvibe?
  The simple method I used is put a big ziptie around the speed knob, so I can control it with my foot, that or a big knob with 1/8'' or better height than anything around it within shoe width.
  cos John Hollis confused me by saying (in the easyvibe FAQs) "Add a pair of break jacks to the LFO rate control so you can use a volume pedal to control the speed" , which seems like it cant be done with adding an LED/LDR module.
  It can be done with an LED/LDR, but since the LFO isn't in the signal path, why not just run it to an outside pot, wired as shown but with jacks to connect the pot outside the box. [I get the idea or maybe don't remember this is a two connector pot wiring assignment, that could be transferred out/in the box using one set of  stereo jacks and plugs, instead of 2x as many mono types] unless there's a ground connection shown, you'll want insulated connections.
  I put a SS phaser in a Vox Wah case,  speed w/treadle control.
  Another way I did it on an EZ Vibe was..take a too large value pot, one that covers the speed range smoothly and mostly [after tapering mods with fixed resistors added to it/around it]...over a small range of its shaft rotation limits, say 1/3 turn [whatever matches the distance the treadle plunger covers..the zipties allow 'fudgeing' the match because they're springy]...then the treadle is easy ['enough' speed range can be had without a rack/pinion drive or string/pulley system], all it takes is a straight shaft through the potshaft [I just epoxied zipties, cut them about 3/4'' long] then Ziptie sticking down from the treadle with zipties right into the ziptie sticking from the potshaft..a nice, slightly 'springy' drive system that covered a nice speed range, and was easy to make and use...I could have had a switch on it to index the speed range to get the slowest speeds...but opted not to.