Bisonic puzzle...

[tsarter]

I’ll post a video of the issue I’m going to describe later, but here’s an issue I’m having with the bridge pickup on my ‘68 Starfire II:

it only happens on the E string. When playing finger style the string is naturally plucked upward. Played with my thumb string is plucked down. Nothing unusual there but when it’s being plucked up, using my finger the output is greatly reduced. Almost like it’s overly compressed. With the thumb and the downward pluck it’s fine.

I can easily compensate and use my thumb on the E string, but I’d rather find a fix. Any ideas?? I’m thinking I may need to dissemble the pickup and take a look. Might be because pole piece adjustment screw is not causing in any movement. If I do the, should I find a diagram of the pickup first?

Any help would be appreciated.

 

[RVBASS]

Are your fingers plucking in the same location as your thumb? If not try the two locations with both your thumb and fingers and see if there is a difference based on location.

 

[lungimsam]

I get a different tone outta my thumb n finger too. Volume about the same though. Finger a little quieter.
Maybe the pole piece height is too close. That can cause weird sonic phenomenae.

 

[tsarter]

Are your fingers plucking in the same location as your thumb? If not try the two locations with both your thumb and fingers and see if there is a difference based on location.

Yes, same location.

 

[tsarter]

I get a different tone outta my thumb n finger too. Volume about the same though. Finger a little quieter.
Maybe the pole piece height is too close. That can cause weird sonic phenomenae.

That's one of the things I'm wondering. Pole piece seems to be stuck, which is why I'm thinking I may need to open it up. Maybe some sort of lubrication may loosen it up?

 

[lungimsam]

Before lubing it, try a couple gentle taps with an object on the tip of the pole piece and the screw head. And I mean gentle. Just to cause some light vibration to see if that breaks it free. I don’t mean using the taps to move the pole piece. But Just to transmit light vibration to it to crack the metals free of any corrosion holding it stuck. Kinda like you do with a bike stem bolt that won’t budge, but scaled way down in power for this application.
Couple very light taps on screw head and pole piece head. then try the screw again.
Maybe use a small screwdriver tip standing on the screw head and then tap the handle with the butt of another screwdriver. Couple light whacks and tgen do it on the pole piece. Then see if it can move normally again.

 

[tsarter]

Before lubing it, try a couple gentle taps with an object on the tip of the pole piece and the screw head. And I mean gentle. Just to cause some light vibration to see if that breaks it free. I don’t mean using the taps to move the pole piece. But Just to transmit light vibration to it to crack the metals free of any corrosion holding it stuck. Kinda like you do with a bike stem bolt that won’t budge, but scaled way down in power for this application.
Couple very light taps on screw head and pole piece head. then try the screw again.
Maybe use a small screwdriver tip standing on the screw head and then tap the handle with the butt of another screwdriver. Couple light whacks and tgen do it on the pole piece. Then see if it can move normally again.

 

[tsarter]

Good idea. And just to be clear, screwing DOWN the screw Raises the poke piece - orcdoninhsvrvthsy backward?

 

[lungimsam]

On my NS Bisonic:
Clockwise raises the pole piece.
Counterclockwise lowers the pole piece.
May take a few revolutions before you can tell the pole piece is moving up or down.
The screw head itself does not rise or fall. Screw head always will stay level with pickup top no matter which way you turn it.

 

[tsarter]

Ok. Got it all taken care of and dialed in. Took pulling the pickups and loosening up the pole pieces enough so they can easily adjust. A very small amount of oil on a q-tip scale to get them sliding up and down did the trick. Have now been able to adjust them to my liking - very close to the strings. It now sounds more like my M-85 with more bite with a very hot signal. Yummy.

Thanks for your input this eve!

 

[Guildedagain]

Lighter fluid - Naptha - is one of the little known secrets as a very light and easy to come by penetrating oil.

 

[tsarter]

Lighter fluid - Naptha - is one of the little known secrets as a very light and easy to come by penetrating oil.

Good to know.
Since I pulled the pickups out and was able to raise the pole pieces by exerting a little force on them I didn’t need anything to penetrate particularly well.