Using Ernie Ball VP Jr. as an expression pedal, should it be 250k, 25k, or modded to something else?

D

DestructionSphere

Member
Wanting to use a couple of VP Jr.'s as expression pedals, wondering how they each react with the Axe FX, and whether or not there is any good linear taper pots to replace the stock ones. Ernie Balls are basically the only expression pedals I like, so I'm willing to go to fairly great lengths to get them working.
 
You want linear taper. Actual value isn't super important here. Anything in the 25k - 500k range should work just fine.
 
I love the EB Jr, but as said, need liner taper so I did (as many has done) a modification to liner taper and a TRS jack and Hey Presto, a great perfect expression pedal.
 
DestructionSphere said:
Do you know of any linear taper replacements? The pots for the EB volume pedals are a bit weird, and I have been unsuccessful at finding anything.
Click to expand...
I just used a large Alpha when I did it IIRC. It wasn't a perfect fit for the EB's mount standoff, but it fit. My modded EB pedal as at my rehearsal space; I poke at it when I go back there next week. Pretty sure it was a spare pot I had left over from a Radio Shack grab bag I got when the local Shack was going out of business.
 
DestructionSphere said:
Any info on where you got the parts for the linear mod? I can't find linear pots for the EB pedals anywhere.
Click to expand...

well, I got mine from an electronic component webshop here in China, but should be available anywhere. If I remember correctly it should be a 10K linear potentiometer and a regular TRS jack. Amazon, Mouser, Radioshack... should have it I guess
 
Regular pots like cheap Alpha pots will not hold up long term in an expression pedal. They are usually only rated for around 10,000 cycles. You want a long life pot that's rated for at least 100,000 cycles for something like wah and whammy use.

I used these Honeywell long shaft conductive plastic pots in my two pedals:

http://www.mouser.com/Search/ProductDetail.aspx?R=380C120Kvirtualkey67850000virtualkey785-380C120K

It's not a drop in replacement though. The pot's mounting bushing is a little larger in diameter than the stock pot, so you have to enlarge the mounting hole a little. You also need to trim the excess shaft length that sticks out past the string pulley. I used a stepped Uni-Bit to enlarge the hole in the mounting bracket but a tapered reamer would work well too. The bracket is aluminum so it cuts easy. I used a hacksaw to trim the shaft.
 
Thanks guys, now that I have a source for the pots this shouldn't be too bad. That string replacement looks like a pain, but I'm sure I'll figure it out after 4 or 5 hundred attempts.
 
It takes a little practice, but it's not bad once you get the hang of it. A long, skinny tool with a small hook on the end helps a lot to reach in and grab the string or spring. Something like this works great:
http://www.stewmac.com/Luthier_Tools/Tools_by_Job/Tools_for_Bridges/Tremolo_Spring_Installer.html
It's a lot easier if you take the screws out of the front jack plate and pull it out of the way too.

If you're going to be gigging with them a lot, I'd replace the string every year or two. They last a long time, but will eventually wear out. The replacement kit is only a few bucks online too. I've always loved the feel of EB volume pedals. Nice long, smooth sweep. If you slide your foot forward on the pedal a little so the axle is right under your ankle, the sweep feels a lot more like a crybaby style pedal for fast wah use.
 
You must log in or register to reply here.
Back
Top Bottom