Bobbin Material - Tell me more...

[frankfalbo]

I don't buy that non-conductive bobbin material should make much difference.

Definitely not much difference. You really have to be concentrating (or run a series of totally controlled tests to define your position on the subject) to hear the difference.

Think about it like this: A capacitor contains a non-conductive material, and it changes the sound right? And if the material changes, the sound changes. The material is called the dielectric. http://en.wikipedia.org/wiki/Dielectric

So if you want to go full nerd on it, you could look at all the places where the bobbin material could have dielectric properties (between the coil wires and the pole pieces, across the top and bottom of the coil wires, etc) and speculate that the material itself may have an effect on the distributed capacitance within the coil, and across different coil layers. But what is more likely is the softness and elasticity of the bobbin material imparts a mechanical resonance into the recipe.

In my research, (highly controlled tests) the way the bobbin sounded when you tossed it onto a table played a role in what the pickup sounded like. If it made a dull "thud" it was relatively neutral. If it had a nice "ping" sound, it was more excited and resonant. Butyrate to me was smooth and soft sounding, and that's what you hear when you wind a coil on it too.

All tests I've performed were without wax potting. It could be argued that wax potting further diminishes the effect of the bobbin material by mechanically deadening the entire assembly. Or, it could also be suggested that wax potting softens and relaxes some plastics more than others. So the pressure of the wound coil may cause a soft plastic to relax under the heat as the bobbin gives a little. A stronger, more rigid plastic may keep it's shape and pressure on the coil.

On a personal note, I like butyrate when it has to be vintage, and glass filled nylon would be my favorite for anything else. Polycarbonate is fine, but I didn't prefer nylon, and I could not find any redeeming qualities for ABS. Like literally, unless you said you wanted to make the pickup sound worse, I would stay away from ABS altogether.