TB+ construction question

[Ken]

Is the chunky rectangular part at the bottom of the TB+ a magnet? If so, what part does that play compared to the coils?  I ask partly because the vintage pickups don't have that.

[gearHed289]

I'm kind of curious about this too. The TB+ in my '94 Les Paul, also a pair I bought off eBay, AND the chrome guitar-sized ones on my Fenderbird look exactly like these on the bottom.

[exiledarchangel]

Yes, it is the (ceramic) magnet, or better, magnets, since there are 3 (one big between the two blades and two narrower outside).
The vintage Tbirds have alnico magnets instead of steel blades, so no need for a magnet on the bottom, thats one of the reasons they don't need as much cavity depth as the modern ones.

[Ken]

Thank you!  I think I see the three you're talking about side by side in the one without the sticker?  What's the copper (?) tape ( ?) across them for?

[exiledarchangel]

Exactly, the copper is used to ground the steel blades.

[Ken]

Thanks a lot.  This puts a lot in perspective.  As far as the difference in depth between the ceramic and alnico, is alnico just smaller?  Why does the ceramic have to be so chunky?

[exiledarchangel]

It is because alnico is both the blade and the magnet, on the other hand steel needs an external magnet.

[Ken]

Is it not possible for the ceramic magnet to be a blade?

[Alanko]

Having, err, smashed one of these pickups out of frustration (an epoxy potted humbucker that is microphonic and prone to interference, how did Gibson f*** this up so badly?) the black rectangle on the back is a pad of epoxy over the copper tape that the coils and magnets are housed within.

[exiledarchangel]

Is it not possible for the ceramic magnet to be a blade?

It is possible I think, the problem is that this pickup would sound very trebly. Iron in a pickup core gives it warm sound (alnico contains more iron and other ferromagnetic metals than ceramic magnets). Think of it like a recipe, too much salt and you are ruing it, everything must be balanced

[Ken]

Got it!  Thanks so much.  I'd love to have been in the room when they decided to go this route with the Thunderbird pickups.  I guess the goal was a more "modern" sound than alnico gives.  I like the TB+ a lot, but the construction seems way less elegant than the alnico ones.

[Dave W]

Is it not possible for the ceramic magnet to be a blade?

Ceramic magnets are  brittle. A ceramic thin enough to be used as a blade would almost surely break with the tensioned wire wound around it.

[exiledarchangel]

True. Also a ceramic blade so thin maybe is prone to demagnetizing.

[Ken]

This is all great info, guys.  Thanks.

[exiledarchangel]

I mean, if there was a way to do it, since it is cheap (ceramic is cheaper than alnico), our friends from the exotic east would have found it and produce it in millions...