Mustang bass pickups - experiments with magnets. Question!

[eb2]

30 years ago radio shack used to sell this package of button magnets. I think it was for guys who wanted to build their kits or stick Family Circus comic strips on the fridge. I bought them and stuck them on the bottom of a Japanese pup's pole pieces in a Kent bass. It did give it a bit more oomph.

[Dave W]

You may have been the last person to ever buy anything from Radio Shack.

[Alanko]

So... neodymium pickups are an astonishingly bad idea.

I took the A polepiece out of the E-A pickup half, and replaced it with a neodymium slug. I plugged the bass back in and gave it a try. The A definitely had a more strident, full tone. With this in mind I removed the other 3 pole pieces...

Problem! In pushing the pole pieces out for the D and G strings the pickup basically fell apart. The coil separated from the flatwork, breaking the solder joints for the coil. I resoldered the coil, glued the flatwork back on and carried on. Once the glue dried I added my neodymium poles. This worked great for the E-A pickup half, but didn't work out so great for the D-G half. The pickup started tearing itself apart again. Basically the neo magnets weren't playing ball. One was pushing down against the pickup cover and the other was popping out the back of the pickup. The effect of this was to, again, pull the flatwork off the coil, re-breaking the solder points. I resoldered again, glued again, let everything set again... This time the two pole pieces tried to join together in the middle of the pickup. In doing so they somehow ripped through the coil itself, making it read an open circuit.


Anybody know Nordstrand's phone number?

[Dave W]

You never know until you try. Sorry it didn't work out.

Substituting or adding neo magnets to an existing pickup might or might not sound good. But there are neo pickups out there that have had a following for years, e.g. Tom Anderson's. I would assume the circuits are designed from the ground up for neo magnets.

[Alanko]

You live, you learn. I was about 30 seconds away from firing up the dremel and installing some Precision pickups instead, but my girlfriend talked sense into me. All the basses I ever took the dremel to have been sold, typically at a significant financial loss...

I have some 'Duncan Designed' pickups on the way from the US. These are probably the exact same pickups as the stock ones I ruined. Some sellers advertise them as being Bullet bass pickups as well, but intended for 'import' Mustang basses (they are all imports here in the UK!!!). Hopefully these aren't made to the specs of the originals, which were a few millimeters shorter than the MIJ Mustang bass pickups. If they are then this necessitates a new pickguard, built to MIJ specs but with the pickup routes for original '60s US Mustang basses... I don't want to do down that route at all.

The biggest surprise was pulling the wiring harness out of this bass. Fender Japan used mini pots (250 k) and a 104/0.1 uF capacitor. That explains why the tone control had so much influence. Both the pickup and the control cavity are totally unshielded, and they didn't run a ground wire between the backs of the pots and the output jack. Lots of fiddly white wire, and the capacitor is actually wired in between the pots, which is a nod to vintage specs, right?

[Dave W]

I'm not sure about the vintage specs. IIRC Pilgrim has a vintage Mustang, you might check with him.

[amptech]

Lots of fiddly white wire

If it's the same wire they use on the Squier series, get rid of it! I am aware that many Squier owners are modding their guitars into insanity, but given the number of Squiers I repaired the electronics are really bad. The pots are one thing, but those 'fiddly' wires (as well as the chinese selector switches) is the main problem.

I think they are made of magnet wire coated with correction fluid

[exiledarchangel]

If I were you, I would also try to stick a piece of soft iron underneath the pickup halves (one piece for each half), you will get some oomph this way and maybe some interesting tone that you may like. That obviously will work only if the poles are visible from the underside of the pickup (so you can stick the iron to them), and you must stabilise it somehow, or else you might get a microphonic pickup.

Also, it is your duty to change the complete harness, especially if you use your pots and expect some reliability from your instrument. Throw those cheap pots, wire and jack to the trash and install some good quality components.

[Dave W]

Also, it is your duty to change the complete harness, especially if you use your pots and expect some reliability from your instrument. Throw those cheap pots, wire and jack to the trash and install some good quality components.

Have we established that this has the same electronics as a Squier? If so, I agree with you, but I would be surprised if the MIJ Mustang doesn't use better components.

[dadagoboi]

Have we established that this has the same electronics as a Squier? If so, I agree with you, but I would be surprised if the MIJ Mustang doesn't use better components.

My MIJ '51 Precision RI has small pots and an uninspiring SC pup.  Wiring and jack are flimsy, too.

It's scheduled for a ThunderBucker rewound '68 Tele pup.

[Alanko]

If it's the same wire they use on the Squier series, get rid of it! I am aware that many Squier owners are modding their guitars into insanity, but given the number of Squiers I repaired the electronics are really bad. The pots are one thing, but those 'fiddly' wires (as well as the chinese selector switches) is the main problem.

Here is a photo of the stock wiring:



This is my attempt at a rewire:



I will re-seat the black ground wires on the back of the tone pot. I used the cloth wire in the end, and I recycled the original capacitor because I liked what it did. The pots are CTS solid-shaft pots, so that I can use some period-correct knobs. I can never make Fender wiring look pretty, but it all works. The black ground wires between the pots and the jack might not be necessary, but it guarantees electrical continuity beyond the grace of everything being screwed to that plate. I used PVC insulation on the wee jumper on the volume pot to ground and on the exposed leg of the capacitor, somewhat unnecessarily.

Before:



After:



Before:



After:



And:



I dislike copper foil. Luckily this stuff cost me relatively little as I bought 'slug tape'. This stuff give paper cuts with ease, and I found that longer strips burled up and stuck to themselves when I removed the paper backing. Annoying when I had taken time measuring it all out. In the end the bass is about 50% measured foil and 50% rammed-in-and-made-to-fit foil. Because I didn't trust the adhesive to be conductive I soldered over every overlap I could find.

For reference this is the shim I made for this bass, which I feel it needed urgently when I first assembled it:

[Dave W]

That ought to take care of it. Is the noise reduced to a reasonable level now?

[Alanko]

I'm afraid I won't know until I get new pickups.

[Alanko]

Quick bump. Pickups arrived today! I epoxied the little neodymium button magnets to the back of the poles, and it sounds great. No electrical noise now. I can take both hands off the bass and hear nothing. Not even a wee 'pop' when I put my hands back on the instrument.

While my pickups were stalling in Heathrow I purchased a second set from a Squier Mustang. It will be interesting to see if these are the same design as the supposed Fender set.

[Dave W]

I'll be surprised if they're the exact same, but you never know.