Feedback with Single Coils on Custom Classic

[Hoffman6000]

I have a Fender Custom Classic Jazz V with Noiseless J Pickups. I ran it through a Little Mark II 2x10 combo amp (w/horn) at medium volume with the EQ flat on the bass and the amp. while standing at a 45 degree angle a foot away from the cabinet, I got a high pitch (around 6-8k) feedback.

I bypassed all effects, and it still happened. I switched to my G&L L2500, and could all but stuff the bass into the cabinet without any feedback. went back to the Fender...feedback...I tried gaining the amp down and turning the master up...feedback...tried turning down a bit...fainter feedback....at higher volumes, the feedback happens when I have my back to the amp up to 2-3 feet away.

wiring inside the cavity looks ok. Bass sounds normal otherwise.

What could cause this? What's the solution? Any advise would be great.

This rig is for a little low end rumble and presence on stage as I use In-ears. I keep it at a bit above bedroom volume.

[walterw]

feedback from a bass? as in a microphonic squeal when you get close to a loud amp?

the only thing i could think of that would cause that is an extraneous piece of metal like a screw or especially a spring stuck to the bottom of a pickup. does the ringing follow one pickup or the other when you switch them?

[MusicBear]

If, as Walter suggested, the pickup and pickup cavity are clean (no loose spring, steel wool fur, metal filings, ...) then the feedback is originating within the pickup itself. If any part of the pickup is loose, then there exists the potential for feedback. A loose magnet or even one single coil winding can cause what you describe.

If you feel inclined to experiment you can try "potting" the pickup - soaking it in something like melted wax (paraffin) - to secure all of the parts together. The benefit would be no more feedback; BUT THERE ARE ALSO RISKS. The risks include (but are not limited to) the possibility of melting (destroying) the whole pickup, or having wax melt out of the pickup onto your bass when playing on a hot stage.

Your best bet is simply to swap out the offending pickup.

[Hoffman6000]

Thanks guys. In my initial trouble shooting/freakout, I didn't think to pan the pickups, but thought of it after teardown..and tonights soundcheck was pushed back and didn't leave time for troubleshooting. I'll take it in to my tech and see what he can find...

[Hoffman6000]

My Tech says pretty much what you were all saying...microphonic...could pot, but might melt...excessive heat....metal touching metal....

the long and short of it is I ordered new American Classic Bartolini's for it and am having them installed this week. According to my tech they are made of different materials and won't have the same problems....I just hope they have the same classic sound.

[walterw]

you never narrowed it down to one pickup or the other?

if it's showing on both pickups, it probably isn't the pickups at all.