EB VP jr. as an expression pedal?????????

[AC30Dirty]

Hey guys, I recently put the new Boss Space Echo pedal on layaway ,which I must say absolutely ROCKS!!!!!! Anyway, I have a Ernie Ball VP jr. that I was wondeing if I could use as an expression pedal for it? I heard that you would have to mod it. I also read on line theat some people do use it as an expression pedal and some don't because it doesnt work. Tone Czar mods the vp jr. which leads me to believe that I might need to do the same. Do you guys have any info on this topic? If I do need a mod could you guys help me out??? Thanks

[Paul Perry (Frostwave)]

So far as I can see, there are two different versions of the "EB VP jr", one has a 250K pot, the other a 25K pot. Arranged, unsurprisingly, as volume controls.

I presume the Boss Space Echo pedal is calling for a Boss EV-5, which is a very different kettle of fish:
"Boss EV-5:  single TRS cable, 10K pot wired as a voltage divider, wiper goes to the tip, ring gets the + from the pedal.  The minimum setting pot on the side I think is either a 50k or 100k, used as a variable resistor between one of the expression pedal pot's (the 10K) outer lugs to ground."

[AC30Dirty]

Now that sounds confusing!!!!!! LOL!!!!!

[AC30Dirty]

Actually....... this doesn't sound to hard if i'm reading it right. From what I can see then the only parts I would need are a 10K pot, stereo jack and either a 50K or 100K resistor. Am I correct on this?

[Paul Perry (Frostwave)]

In fact you don't even need the resistor, the only function of that is to reduce the range of the pedal (that is, stop it from turning right down).

In fact, I strongly suspect that you could get away with the EB VP jnr, if you were to rewire it so that there was a cable coming out with a tip/ring/sleeve plug on it, where the pot wiper goes to the tip of the plug, one end of the pot goes to the ring, and the other end of the pot goes to the shield.
(swapping the pot ends will make the action reverse).

[AC30Dirty]

HHMMM...... im definitely gonna try this sometime this week. I'll get back to anyone on this thread for some help if I run into problems and the results if everything goes well. Thanks

[Plinky]

No one ever posted results, so I thought I'd share mine. The wiring that Paul Perry suggested will work. I tried it on an old Boss FV-50L volume pedal to make an expression for my Eventide TimeFactor. It works perfectly. I just unsoldered the pcbs connected to the main pedal pot and the tuner out jack and tucked them out of the way inside the pedal in case I wanted to solder it back. I then soldered new leads from the main pot to the tuner out jack. Took about 5 minutes.

[Nitefly182]

I own a Toneczar expression pedal. Ed replaces the pot with a bourns pot and adds a number of switches for sweep direction and taper. It works very well.