Nordstrand makes dual coil pickups, which you can read about here. I have a couple of noob questions about them. It doesn't specifically say whether they are active or passive, but I'm assuming the convention is that if it doesn't specifically say it's active, then it's not? It refers to split-able installation. Does this mean that it can be wired so that you can turn off one half of the humbucker, for that single-coil sound? Finally, they say that parallel pickups are better for split-able installation, because then you don't see a loss in gain when you switch to single coil. Wouldn't you see an increase in gain when switching from parallel? Seems to me that the problem would exist either way. Also, is this a big deal? I'd like to be able to switch between series and single coil. Will there be a noticeable, problematic gain loss if I do this? Thanks!