HELP: Neck pup is off when rolled back a little

If I had to guess, I would say your pot is bad.

 

I think it's a logarithmic pot. You should get a linear one.

 

Volume pots should always be log. Tone pots can be linear but log seems to be more common. Unsure why.

Might be a bad pot. The CTS pot I put into my bass recently is doing the same thing. I'll be replacing it fairly soon but for now it's working when full up, which is the only place I leave it.

 

500k or 250k pots aren't really an upgrade, they are just different. If you feel your bass isn't bright sounding enough switch to all 500. If you like it the way it is, stick with 250k.

Its possible you got it to hot with your soldering iron when you installed the new pots. I have done that before. Or a piece of hard solder or wire could have gotten into the pot and damaged it.

 

I noticed crappy pots have a tendency to do this on Jazz basses for some reason. I would stick with the 250k, but just get a better quality pot. CTS is good, but make sure it is one of the better ones as they make 'cheaper' models too.

 

2 things.

1. Check your solder points just in case. You never know.

2. Clean your pot. DW40 or any similar lube will do. Spin that pot till it's super clean. I won't pretend to understand exactly how a dirty pot can act so weirdly, but I have observed it myself recently. My volume pot was acting about how you described. Cleaned it and it's fine now.

Hope you get it working the way you want. I've also noticed this sort of problem when a tone cap starts to die (I use old vintage caps, so it happens sometimes). It does something weird to the circuit. Doesn't sound like this would be your problem though.

 

Don't use WD40 or any similar lube to "clean" a pot. It's just going to muck it up with more crap.

Use an electronics cleaner, like Detoxit.