Re: New to Phat Cats- your opinions, please!
The bridge & neck both have twin A2 magnets (positioned so they repel). From comments here, these seem to work best in bright woods (I'm anti-Fender, so I have to take their word on it).
In warm woods & designs (LP, SG, 335) they are not at their best with the stock magnets. I was not at all impressed initially. The neck is very dark, and overpowering, and the bridge weak & thin. But once I figured out I could swap magnets in them, and they didn't have to be two of the same kind of magnet, then they blossomed. Then they become wonderful raw, open, single coils as the good Lord intended.
With a mag swap, a pair of Phat Cats is great in any Gibson design, especially an LP. I also use them in SG's and 335's. One of my favorite PU's now. Their metal covers give good shielding & they seem to have less noise than most P-90's.
Neck - depending on the wood's tone and how bright you what it, these pairs are ranked in order from warm to bright (but even "warm" here is brighter than the stock magnets): A5/A2, A5/A4, A5/A3, and A5/A5. All of these are good. For my LP, the A5/A3 works best. In my SG's & 335's, the A5/A4 is preferable (A5/A3 was a little chimey). Your tastes may vary. Swapping mags is very quick and easy and the results are worth a few minutes of your time. HB's are very mid-focused by nature, and that sometimes causes them to be muddy in the neck slot.
Bridge - I needed more muscle & more body, so I settled on an A8/A4 pair. More output, more mids, tighter low end, and better treble to cut thru. Plus it balances better with the neck. So far this is what I've used in my bridge PC's. I don't understand why they spec'd them out with A2's.
I use PC's in the neck with an HB bridge, and also in a pair. Both are nice.
