Pickup Magnetics 101 Part2

[jps]

...make it sound more '60's ish.

For one thing, make sure you have the .0047µF cap in line. Tell this hypothetical "Kevin", congrats!

[teeder]

Thanks!

I really didn't need it, but I've wanted an extra one to experiment with.

[cjj]

So, hypathetically, a guy, let's call him "Kevin", bought said RIHS and wanted to make it sound more '60's ish. What would you do, remove a certain amount of the windings, change the magnets, both? Just askin'.

OK, Pickup Magnetics 101 is back in session...

Getting the coil to a similar number of windings (similar resistance, assuming they used the same diameter (gauge) of wire) would be a start. If by " '60s-ish" you mean sounding like one with magnetic shoes, well, that's probably a harder problem.

A fair amount of the sound of a pickup comes from the coil's inductance/resonance. Inductance is a fancy term to describe the "resistance" of a coil in terms of what it does to an AC (sound) signal. When you measure with an ohm meter, you see the DC resistance, but this is not the same as inductance. The DC resistance will look the same if a coil is wrapped around a cardboard tube (air core) or a big chunk of iron. The inductance however, will be much higher for the iron core than the air core. Why? Well, an AC signal flowing in the coil creates its own varying magnetic field, which in turn induces (hey, that sounds kinda like inductance, huh?) electric currents in the core. The current can't flow through air, so there's no effect, but the current in the iron core will have a big effect.

So, back to HS pickups. The RIHS has Alnico magnets as the core. The old magnetic HS has iron (steel?) rods. These will, I'm pretty sure, behave differently as a core material, so it's likely the pickups will sound differently just because of that.

Then there's the magnetic field itself. The strength and shape of the magnetic field around the strings and the coil also has an effect on the sound. In the RIHS, the Alnico pole pieces are the magnets and create the field. The steel shoes will direct the field through themselves and around the strings/coil. In the old HS, the shoes are the magnets and the field is directed through the iron pole pieces. Are these fields the same shape and strength? I doubt it, though they may be similar. Figuring that out would take WAY more math than I care to do (or can even remember)...

[jps]

I really didn't need it, but I've wanted an extra one to experiment with.

[johnallg]

So, hypathetically, a guy, let's call him "Kevin", bought said RIHS and wanted to make it sound more '60's ish. What would you do, remove a certain amount of the windings, change the magnets, both? Just askin'.

You could try to unwind to the 7.4k range, and also if you were really anal about it, change the magnet rods to Alnico4 from the Alnico5 in the RIHS. Not sure that would be closer to the original magnetic shoes, but it would elicit a change.

[BAD RONBO, KiLLeR DWaRfS]

the coil wires were wrapped directly on the slug mags on my '85 re-issue horse coil as that was all that was holding the coil forms together. are they still made this way ? weemac can verify on mine.

[teeder]

I had to back out of this one. Timing is everything!

[Seans]

the coil wires were wrapped directly on the slug mags on my '85 re-issue horse coil as that was all that was holding the coil forms together. are they still made this way ? weemac can verify on mine.

Yep, and the screws that hold the shoes are a tad long, so they push the already too high A and D strings slugs higher still, especially the screw sans earth terminal.