Boss DD-3 mod help.. delay time controlled by a wah style foot pedal.

[f0rk]

So, I'd very much like to be able to sweep the delay time with a wah style foot contrloer. anyone know an easy way to accomplish this? I hear there is a gizmo out there that will give me what I need. Help please.

[5150]

In his instructional video John Petrucci uses an expression pedal (the controller I think you intended to identify) to control the amount of reverb/delay/whatever, and I'm guessing you have a similar intent in mind.  I don't know how this will work if the parameter isn't controlled by a simple pot, but if it works like that then you're set.  The first thing I would think of would be to find an old wah or volume pedal, or buy an enclosure for the project (first one I see is at  http://www.smallbearelec.com/Detail.bok?no=548 ).  Once you've gotten that figured out, pop open the delay and find the control that you want to have changed by the expression pedal.  Note the pot value - this will be the value you need inside the pedal itself.  If it's just three wires going to it, then desolder them, figure out some way to remember where each went (you'll need that, try sticky notes or paper on a thread), and put the pot inside the expression pedal enclosure.  Then (probably the only thing you can really screw up) look at the schematic at        http://www.diystompboxes.com/pedals/zoom1.jpg      which is for a basic expression pedal, and wire the potentiometer and the original wires to corresponding parts of a stereo jack (yes, you'll have to drill holes for that).  Connect with a regular guitar cable and you're set. 

Note that you may have to either experiment with different potentiometer values or have a simple gear/pulley system (so the pot travels fully from one side to the other within the controller's range) to get the right sweep, as the expression pedal likely will not cover the full range of the pot and thus give the wrong resistent values at one or both of the ends.  If you really want to be specific about the values, grab a multimeter and test the resistance at both ends of the pedal's sweep.

If anyone has a better idea, let me know too.

Jeff

[tommy.genes]

If you do a search of this forum, you should be able to find a Boss DD-2/3 schematic.

Glancing at mine, the Delay knob is a 10k log pot with "clock low" and "clock high" trimmers on either side of it. You could probably install a normally-closed jack (might have to sacrifice your direct out jack to make it fit) that allows the control voltage to pass through the on-board pot when nothing is plugged in, but that redirects it through an outboard pot (expression pedal) when it is plugged in. You're really not changing the function of the circuit at all, you're just switching between this 10k log pot over here and that 10k log pot over there.

Looking at the schem again briefly, you might need a Tip, Ring, Sleeve (TRS) jack with normally-closed connections on all three. Aron has those in his STORE (the "Marshall-style switching jacks").

-- T. G. --