Neo magnets and big distance from the strings: would I miss anything?

[David Schwab]

"One must be skeptical of your findings as well, which is why I questioned why you wound the pickups so low, when the discussion was about over wound pickups. Overwound pickups are dark sounding."

The discussion was also about whether you can make a pickup brighter by replacing a single coil around a set of pole pieces with individual coils around each pole piece. I showed you that they sounded the same, with my number of turns. I also showed you why you would expect the inductance to be the same, in general. Why do yours sound different? Why do the single versus multi coil pickups sound different when there are lots of turns, but not when there are not so many? Changing the inductance affects the sound with brighter pickups as well as darker pickups, and since I showed that the inductance should not change, what is going on?

Go back and read it again. The Wal was specifically mentioned, and it was said that any single coil, or even humbucker that measured as high as the Wal in DC resistance would be dark sounding. So the point is you can wind a 15K humbucker with 42 gauge wire, and it's going to sound like mud. You can wind a 15K multi coil pickup with 42 gauge wire and while it has a very thick low end, it's pretty bright sounding.

Your examples used very low wind pickups. All pickups wound like that will be bright. But even then, the multi coil you made was brighter.

Why would it happen? I don't know, but it's a reproducible affect.

In the 1976 patent (3,983,777) by Bill Bartolini, he has this to say about multi coil pickups:

"Prior art variable reluctance pickup systems having a single coil for sensing variations of the magnetic circuits have very poor high-frequency responses. Specifically, the impedance of a sensing coil in a magnetic circuit increases with increasing frequency up to a maximum at a resonant frequency whereupon the impedance of the coil decreases. Below the resonant frequency, the impedance of the coil is dominated by inductive effects. In explanation, the resulting variations in magnetic flux due to string vibrations induce an electrical signal in the coil which, in turn, creates another magnetic field which "bucks" or opposes the variations in flux induced by the string (Lenz Law).

This effect "impedes" the signal and increases with increasing frequency. Above the resonant frequency, the impedance is influenced by the capacitive effects between turns of the coil and between layers in the coil winding, i.e., the changing current in one turn of the coil influences current in neighboring turns of the coil. This effect becomes larger with increasing frequencies such that the coil behaves as a capacitive reactance with turn-to-turn capacitive leakage to ground. Accordingly, the output signal from the sensing coil falls off rapidly above the self-resonant frequency. Both the inductances and the capacitance of a sensing coil vary linearly with the mean radius of the coil. The mean radii in single-coil embodiments of prior art variable reluctance pickups are large. Hence, the "attack" portion of a note is not reproduced accurately."

Also, when you showed the inductance would be the same, how did you do that? Did you actually measure a pickup wound as we were discussing?

[Joe Gwinn]

Would it be possible to repeat the experiment, without significant clipping? This will remove a variable, and may be the quickest way home.

[Mike Sulzer]

Also, when you showed the inductance would be the same, how did you do that? Did you actually measure a pickup wound as we were discussing?

That is what I remember, but I cannot find that discussion. Do you have link? My memory is that I showed it in theory, wound the two pickups, measured them and did a listening test. Maybe I am remembering too much?

Also I think we discussed that bit of Bartolini patent babble. Why is it babble? Read it carefully. He is saying that the benefit from the multiple coils over the single coil is lower capacitance, not lower inductance. Well, he is right, the capacitance is lower but it does not help significantly because the cable capacitance dominates over the coil capacitance and so you really cannot move the resonance very much. It is just something to say that will get by the examiner and allow you to patent something that you should not be able to.

[David Schwab]

Would it be possible to repeat the experiment, without significant clipping? This will remove a variable, and may be the quickest way home.

Sure. As soon as I have time I'll redo it.

[bea]

In order to understand the result it would be important to know about the location of the magnets.

In a construction like gibson's infamous bass sidewinder i would suspect the large magnets outside and closer to the strings than the central steel bar lead to a large aperture making the PU still sound dark (yes, i am aware of its position...).
(which makes them sound dark even if their resonance is 3.1 kHz [one of my Epi low-Z sidewinders with additional steel bar in the centre]).

[David Schwab]

And they'd need no routing on the top, so they would be "invisible" from a frontal view.

How do you propose making them not seen if they are not routed into the body?

[David Schwab]

In order to understand the result it would be important to know about the location of the magnets.

In a construction like gibson's infamous bass sidewinder i would suspect the large magnets outside and closer to the strings than the central steel bar lead to a large aperture making the PU still sound dark (yes, i am aware of its position...).
(which makes them sound dark even if their resonance is 3.1 kHz [one of my Epi low-Z sidewinders with additional steel bar in the centre]).

Those pickups sounded dark because they had 24,000 turns of 42 gauge wire, per coil. You can wind the same pickup with less wire and it will sound brighter like a single coil pickup.

Those Epiphone versions are very odd, with the heavy gauge wire on them. I'm not sure what they were trying to accomplish there. I just rewound one of those the other day.

The '76 Bicentennial Thunderbird pickups are very similar to the EB-0 sidewinder. They have the steel plate running between the two coils, but have an alnico magnet in where the screw poles would be, and a lot less wire.