I agree, it's not just the lack of potting, it's also the wind, the materials, and sometimes even the springs that the pickups are mounted with (or without ie P90). And frankly, some pickups have it more than others. My old USA LP Special had it and it followed the pickups (SHED P90s) when I swapped then into an SG! You can hear every time I hit the pickup selector here. And even with the tone knob turned down to 0 during the woman tone sections you can hear it...
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