aluminum domes in K120

[Krischu]

I havn't seen an original aluminum dome yet but I wonder whether the circumference of the dome - the folded edge - has little cut-outs where the voice coil wires travel across the cone surface.

Since the voice coil wires form an obstacle prveventing the dome edge from touching the paper cone on the full circumference I think the dome edge should be either punched out or dented in, to bridge the VC wires underneath.

[edgewound]

I havn't seen an original aluminum dome yet but I wonder whether the circumference of the dome - the folded edge - has little cut-outs where the voice coil wires travel across the cone surface.

Since the voice coil wires form an obstacle prveventing the dome edge from touching the paper cone on the full circumference I think the dome edge should be either punched out or dented in, to bridge the VC wires underneath.

Nope...no cutouts.

[GordonW]

With the modern edge-wound coils, the leads coming out of the coil are FLAT wire, and as such, do not require any vertical clearance for the dustcap.

My only precaution, is to put a tiny piece of adhesive tape, over the lead wires, where the dustcap flange will sit, to avoid the possibility of the lead wire shorting to the aluminum cap. While there should be enough adhesive/insulation already on those lead wires, it never hurts to be safe...

Regards,
Gordon.

[edgewound]

My only precaution, is to put a tiny piece of adhesive tape, over the lead wires, where the dustcap flange will sit, to avoid the possibility of the lead wire shorting to the aluminum cap. While there should be enough adhesive/insulation already on those lead wires, it never hurts to be safe...

.

I wouldn't use adhesive tape to insulate the lead wires....it's not up to the duty required, and would make for a not very attractive look. A current factory kit has the leads insulated with cyanoacrylate adhesive. The vintage kits were insulated with Bostik rubber cement...tacked to the cone. Ya gotta remember that one of the highly regarded elements of a Genuine JBL product is the fit and finish....accept no less.

[GordonW]

Cyanoacrylate over the lead wires is a much more durable medium, to avoid the cap "knifing through" the adhesive, as could happen with the older kits. With Bostic adhseive, I definitely liked to have the leads taped. Plus, the brown/black Bostic would easily hide the tiny bit of tape...

With the cyanoacrylate over the lead wires, no further insulation should be needed, in theory, at least... but IMHO, a tiny bit of clear vinyl tape placed over the leads, and then the dustcap glue flowed over that (if you cut the tape precisely enough, you CANNOT see it outside the cap)... that'd be my recipe for foolproof, failure-resistant work. IME, I've learned to make the things as "bulletproof" as possible, as hard as some of these guitar players hammer on these things...

But, with the newer ones, it should be OK with just the layer of superglue... it's much tougher than the Bostic...