jazz bass pickup and stacked pot questions

[mkat]

Just a few questions on the Fender jazz bass pickups:

- Was the Fender jazz bass magnet polarity and winding direction of the pickups always set as humbucking? Is this really necessary?

- Why the change from the stacked pots to the 3 and from memory 4 pot layout? Any issues with the stacked pots?

[David Schwab]

Just a few questions on the Fender jazz bass pickups:

- Was the Fender jazz bass magnet polarity and winding direction of the pickups always set as humbucking? Is this really necessary?

I believe it was. It's not necessary, it was a feature. At the time Gibson had come out with humbuckers, so Fender had to find ways to do hum cancelation. The P bass pickup squeaked past Lover's patent, even though he had a similar arrangement. Fender got a patent on a split pickup, but it wasn't for hum cancelation.

So Fender did the hum canceling thing with the Jazz Bass, and Jazz Master guitar, Jaguar, and the Mustang. I'm not sure if Tele's were or are that way. Every time I have a Tele in my hands I forget to check!

There's no reason to do it except to get rid of hum.

- Why the change from the stacked pots to the 3 and from memory 4 pot layout? Any issues with the stacked pots?

I'm guessing because the stacked pots were more money. It does give you two tone controls, and that might alter the tone slightly. The current basses have two volumes and one tone.

It does look really cool though.

[Phil m]

I read an old interview with John Entwistle somewhere (EDIT: now I remember, his bass collection book) where he mentioned he liked the sound of the Jazz bass with the stacked pots a lot better than the 3 pot configuration.

[mkat]

Good stuff, thanks for that. I have a cheaper Fender jazz bass and made a set of pickups for it to replace the crappy set that were in it (not humbucking). There is shielding paint in the cavities and I grounded the magnets and noticed that there is minimal hum. I think the grounding can also be improved on this, so that's another thing I'll compare.

The only thing I don't like is the 3 pot setup. I have parts for a stacked pot configuration, so I'm going to rewire it this way to compare. There should be more options with this setup tone wise.

Also, is it pure brass plates that Fender used in the pickup cavities?

[Phil m]

Where did you get the stacked pots?

[mkat]

Where did you get the stacked pots?

Guitar Parts Resource have the CTS concentric pots, appropriate knobs and control plate. The control plate is really easy to make though.

[David Schwab]

Also, is it pure brass plates that Fender used in the pickup cavities?

You mean the plate under the pickup? Yes. I have a few of those in my parts bin.

[mkat]

Actually, would the standard '62 wiring diagram work for this setup since my pickups are not wound for humbucking (two single coil pickups, same polarity, same winding direction)?

[mkat]

You mean the plate under the pickup? Yes. I have a few of those in my parts bin.

Yes, the plate under the pickup with the foam on it.

[David Schwab]

Yes, the plate under the pickup with the foam on it.

yeah, it looks like brass.

[mkat]

Thanks for the info. I made two sets of pickups for the bass, really happy with the sound:

- vintage style set
- overwound set for added beef

The '62 wiring has changed the tone as David mentioned, I think it has more options than the 3 pot layout apart from the lower end. There is not as much bottom end range as the 3 pot configuration, which is ok. It has a more defined and tighter low mids. In saying this, I'll also try using the 3 pot setup with these pickups since I'm comparing against the stock Fender pickups with the 3 pot layout.

I've been making the flatwork myself, but did use the Allparts flatwork for the neck pickup since I couldn't use machinery last night due to the noise. Just a warning on these to anyone considering buying them, as they are too thin and not wide enough (the thickness and width differs to their bridge counter parts which are fine and standard Fender dimensions for vulcanised fibre flatwork on jbass pickups).

[mkat]

Phil, I just noticed that AllParts also have the stacked pots.

[Phil m]

Thanks Micheal, BTW did you use a regular 2 pot/2tone/2 pickup schematic for it or did you find the original Fender schematic somewhere?

[mkat]

Phil, the wiring diagram for a Fender '62, don't know if it's the reissue, is available on the Fender site. Look for "American Vintage '62 Jazz Bass®":

http://www.fender.com/support/wiring...sts.php#basses

It's more work wiring this setup, but interesting to hear the difference.