Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups

Degaussing, or "aging" AlNiCo pole pieces

Discussion in 'Just Pickups' started by Antigua Tele, Feb 17, 2018.

  1. philosofriend

    philosofriend Tele-Holic

    Oct 28, 2015
    Thanks for the info. Gives me hope for being able to adjust non-adjustable pickups to get all the strings equally loud. Yay!

  2. Barncaster

    Barncaster Doctor of Teleocity

    To the original premise of this thread, I’m in agreement. I don’t think there is validity to the concept of degaussing magnets to sound like vintage magnets. It’s based on the incorrect assumption that vintage instruments sound great partly because their pickup magnets have naturally degaussed over time to some level that makes the pickups sound really good.

    Alnico is classified as a permanent magnet material per Bill Lawrence. This means it may only lose a few percent of its gauss level over a century. In our industry, we are talking about 70 years max so I don’t think time is in play here.

    I think the real issue here is very complex. In my testing, the impact of gauss levels on Fender style single coils is much more critical than on PAF style humbuckers. The real issue is Alnico 5 rods. A typical Alnico 5 rod will saturate at about 1600 gauss which is about double of Alnico 2, 3 and 4 due to a special heat treating process which aligns the magnet’s crystallinity along its magnetic axis (anisotropic).

    It seems more recent pickup manufacturers have treated charging A5 rods with as if the were like the isotropic grades (A2, A3, A4) which saturate in the region of 800 gauss and sound reasonably OK there. It’s a very interesting experiment to hear the tonal differences of a Fender style single coil with different magnet array gauss values. To my ears there is a radical difference in tonality in relation to gauss levels. A Fender style single coil equipped with a saturated array (approx 1600 gauss) sounds really bad.
    Derek Kiernan likes this.

  3. Antigua Tele

    Antigua Tele Tele-Afflicted

    Jun 2, 2014
    west coast
    In my testing I've found that magnetic string pull has a complex effect upon the tone. I've recorded string plucks with the pickups set close, and then set far away, and then I looked at the differences it causes in FFT analysis, where the amplitude intensity of each harmonic can be seen Everyone knows that really strong pull causes "stratitus", but even when the effect is no so strong as to be undesirable, there is an effect. The reason the effect is so complex is because the pull upon the string, in a particular location along the length of the string, causes a shift in energies between the harmonics levels. For example, if the pickup is pulling at the anti-node of the third harmonic, it will make the third harmonic louder, while causing other harmonics to become quieter. The effect is also not instantaneous, it changes over time, as energies shift between levels, producing a beating and some harmonic levels, while leaving others untouched.

    In general, the farther the pickups are away from the strings, the more "naturally" they vibrate. The closer the pickups to the strings, the more interference that is caused by the pickups. AlNiCo 2 is reputed to have a different tone in general than AlNiCo 5, be it with humbuckers or Strat single coils, and so for the reason stated, I would say AlNiCo 2 is associated with natural string movement, while AlNiCo 5 is associated with disturbed string movement. If you set a piuckup with AlNiCo 5 very low, its pull upon the strings will be weak enough that it effects the strings as little as does a pickup with AlNiCo 2 that has been set closer.

    Regarding AlNiCo 3 and 4, just take a look at any AlNiCo datasheet and you can see that they're barely any different from AlNiCo 2 in nearly all performance measures. AlNiCo 3 is like a slightly worse AlNiCo 2 that was devised in response to the high cost of cobalt. As a part time rationalist, part time subjectivist, I don't believe there is any meaningful difference between them in the guitar pickup context.

    Regarding AlNiCo 5, I do measure around 800G with lower AlNiCo grades, but I've tested dozens of AlNiCo 5 Strat pickups and find that usually read 1050G on center, a little higher at the edges. Part of that is because the adjacent return paths cut the Gauss down by about 100G, so if the pole piece is free standing, it measured around 1150G. When freshly charged with a neo measuring about 3,500G, the A5 pole piece measures ~1250G, and settles down to 1150G after about five minutes or so. I've never been able to get Strat/Tele type A5 pole pieces up ~1600G.

  4. highwaycat

    highwaycat Tele-Meister

    Jun 15, 2017
    I'll just stick with setting my noiseless singlecoils very low. Couldn't be happier.

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