Re: A8 in Antiquity P90. How much more oomph?
What's in the Antiquity P-90 now, A2's? A8's will be noticeably louder. I just don't see twin A2's working in any P-90 in any position: weak in the bridge and dark in the neck. If the Antiquity has A5's, A8's won't give much of a boost, but they will add mids. Is more output what you're looking for?
I've got a pair of A8's in a Phat CatB in a LP Std, and am considering swapping them out for a pair of RC A4's or UOA5's, as they're a little brighter and thinner than I want.
I have a pair of SP90-2's in an DC LP Special (thick, flat slab of mahogany), and immediately pulled the ceramics out of them. I put an A8/A4 in the bridge and A5/A5 in the neck, and it sounds great. Raw and powerful, but with enough midrange to make it full.
You can do so much with P-90's and magnets, I hang on to mine for future projects (or future guitars). In a HB, you have a 1/2 magnet to coil ratio; in P-90's it's 2 magnets per coil. So magnets have a large impact on a P-90's EQ. In bridge Phat Cats/P-90's I also have: A8/A5 and A4/A4.