Ernie Ball VPjr - replacing the pot with a linear taper pot

jleader

Member
A couple questions for anyone here who has an EB VP Jr and has replaced the pot with a linear taper pot:

Do you happen to know value and dimensions of the replacement, and possibly where you purchased it?

Any help would be highly appreciated. I haven't had much luck finding anything locally that would have a long enough shaft for the brass pulley... And yes, I'm anticipating this being a royal pain in the @$$ putting everything back together :lol: .

Thanks in advance!
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

jleader said:
Do you happen to know value and dimensions of the replacement, and possibly where you purchased it?
24mm with a long shaft. I cut the shaft down once I had attached their bobbin. 50k. I think the ones I used were from Radio Shack. Or Small Bear. Or Active Electronics. Hard to say. I've got a pile of them here that have accumulated over the years.
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

You don't need to replace the pot--you can alter the taper by adding a resistor between the ring and the tip of the output. You can also buy an insert cable that does this for you: Easy Expression Converter
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

LMO said:
You don't need to replace the pot--you can alter the taper by adding a resistor between the ring and the tip of the output. You can also buy an insert cable that does this for you: Easy Expression Converter
I didn't have much luck with the Easy Expression Converter when I tried it. Knowing me, I probably specified the wrong version when I ordered it though. :? That's been known to happen!

iaresee said:
24mm with a long shaft. I cut the shaft down once I had attached their bobbin. 50k. I think the ones I used were from Radio Shack. Or Small Bear. Or Active Electronics. Hard to say. I've got a pile of them here that have accumulated over the years.
Thanks! I'll give Radio Shack another look then. I was hoping I could find something I could "drop in" with minimal fuss (or as little as possible) but if not, that's hardly major surgery.
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

Just solder a 25K to 50K 1/4W resistor between the ring and the tip--much easier and cheaper than replacing the pot. I've attached a set of before/after charts to show the results (file corrupted during forum transfer).
 
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Re: Ernie Ball VPjr - replacing the pot with a linear taper

I went through all the hassle of changing the pot then I discovered I could change the taper in the software of my Gordius Little Giant :oops:

I never did figure out how to do it in the Axe-Fx, you can change the expression curve so it should be possible.
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

LMO said:
You don't need to replace the pot--you can alter the taper by adding a resistor between the ring and the tip of the output. You can also buy an insert cable that does this for you: Easy Expression Converter


I've experimented a lot with different resistor values etc. to get a more even response from my EB6166 pedals but I never got a response I was happy with until I finally did replace the pot. YMMV but the resistor is a far from perfect solution IMO.

S.R.
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

After the Easy Expression cable, I've been dead set on replacing the pot as that seems to be the source of the problem. Sometimes you can get away with a "band-aid" fix (adding something to what's already there), sometimes you gotta do surgery (remove and replace parts). The way I see it, either solution can be the "right" one, but this time, my EB's going in for surgery.

Thanks to all for the suggestions and advice, it's much appreciated!
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

POB said:
I never did figure out how to do it in the Axe-Fx, you can change the expression curve so it should be possible.

I was quite happy with changing the slope to 12%...
 
Re: Ernie Ball VPjr - replacing the pot with a linear taper

POB said:
I never did figure out how to do it in the Axe-Fx, you can change the expression curve so it should be possible.
The trouble with this is that the Axe-Fx only sees non-zero values for about the last half of pedal travel. You can change the curve all you want, but you can't do anything with all those leading zeroes... :(
 
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