Can pots go microphonic?

[pedalguy1]

I have a fender deluxe precision special with an active EQ the pot that controls the mid frequencies has become super scratchy and poppy when i turn it. The problem is, this is the second time this has happened. I paid to get it fixed the first time and the second time i just busted out the soldering iron and wired it in myself. I'm pretty sure it just used a 250k pot, but whats to stop it from happening again? Do i just have bad luck with cheap parts?

[bassbenj]

Originally Posted by pedalguy1

I have a fender deluxe precision special with an active EQ the pot that controls the mid frequencies has become super scratchy and poppy when i turn it. The problem is, this is the second time this has happened. I paid to get it fixed the first time and the second time i just busted out the soldering iron and wired it in myself. I'm pretty sure it just used a 250k pot, but whats to stop it from happening again? Do i just have bad luck with cheap parts?

Welcome to the "I just had to replace the cheap crappy Fender Mid pot on my bass again" club. I'm not the first member, but I'm definitely a member. And I probably made a mistake when I replaced it with a genuine Fender part...

[pedalguy1]

Glad to know i'm not alone. Oh well, its a cheap fix. Although i sometimes day dream of a simple passive bass. lol. So much less to go wrong.

[bongomania]

There are crappy pots and defective pots, but not microphonic pots.

[pedalguy1]

Cool, thanks bongo. Its just i could literally tap on that mid knob and an audible pop would come through the speakers. Looks like its time for a replacement.

[miramadar]

Its just i could literally tap on that mid knob and an audible pop would come through the speakers.

I would be looking for a bad connection on the pot itself.

[Jim Carr]

Before replacing the pot try these two things with bass UNPLUGGED:

1) Work the knob back and forth eventually covering the whole scope of it's travel for a couple of minutes. Yes, it will wear out sooner, but the dirt/corrosion will be worn away from the wiper and inner surface of the potentiometer.

2) Radio Shack "Cleaner/Lubricant" spray for contacts/electromechanical parts. Follow directions on the can.

3) Replace it if these don't correct it enough.

[SGD Lutherie]

Is the back of the pot grounded? If not, that sometimes causes noise, especially on treble controls.

[bongomania]

Originally Posted by pedalguy1

Cool, thanks bongo. Its just i could literally tap on that mid knob and an audible pop would come through the speakers. Looks like its time for a replacement.

As the other guys suggested, a bad solder joint can cause popping noises. When you tap it, the joint shifts a bit, causing a little voltage spike that you hear as a pop.

[grisezd]

Take the cover off, plug the bass into your amp (quietly!) and push and pull on the connections. Same sound? If so find the wire that's the problem and fix it. If not look for a bad solder as Bongo (and others) said. It took me a few shots to learn to solder properly. Make sure the back of the pot is clean (and abraded, if you like) before you solder there, and be sure to get enough heat that the solder flows nicely rather than just drips on and "sticks".

[addylewis]

I may have a go on that myself - mustang bass with intermittant/buzzy volume knob...WD40 didn't help, the wires all appear to still be soldered...

[pedalguy1]

Thanks for the suggestions guys. When I put this last pot in myself it worked like a charm and was super quiet just like new. I haven't played the bass in awhile and now its cutting out. It may just be my amateur soldering job.

[Jim Carr]

I still vote for corrosion and/or dust. I have a couple of instruments that don't get played for months at a time. Usually, they suffer from noisy touchy pots when first brought back into action.

[Metal Mitch]

Originally Posted by bongomania

There are crappy pots and defective pots, but not microphonic pots.

I'm not sure about that... I've had several MIJ imports where the stock electronics would make a noise while turning the pot. Like, you turn it down, then turn it all the way up real fast - when the pot hits the end of it's travel, it sounds like banging on the side of a water tower with a hammer. Lotsa reverb without any effects help. Changing out the pots fixes it.

[bassplayer20000]

Can anyone help me I have a 1980 fender precision special bass made in usa and trying to locate and purchase the original pickups and wiring loom for this bass which is the first precision bass to have active pickups . I'm in New Zealand and parts are hard to come by