I don't think that many have tried as many 3 pickup LP's, or have built as many, as I have... over 50 and counting!
My takeaway from it all.
1: it looks awesome.
2: it allows for great tonal options, IF you wire it up smartly!
3: a 5 way switch and 2x volume 2x tone is a great setup, but a bit cumbersome to wire, especially if you want splits.
4: a humbucker in the middle is the best option, over a phat cat/p90 pickup, if and only if you can use it as 2 singlecoils (more on that later).
My recommendation is this.
* Get the pickups you like. Seth Lover set? Great choice. Get a pickup in the middle that matches the look, but is as bright and jangly and low output as possible.
* Wire up the LP as usual. In other words: forget the middle pickup exists, for the time being.
* Once bridge and neck are hooked up, use 2 push pull pots to split bridge and neck individually. You only need 1 pole of the push pull pot to do that. Use the other, to engage one coil of the middle pickup! So, if you split the bridge to the outer coil, you engage the coil furtherst away from that coil. Neck, ditto but in reverse of course. That way you get the most out of that middle pickup, tonally. As a humbucker, it's way too fat to do any good there. You need that superlow output and bright tone to act as a singlecoil to enable those quacky tones. Why else would you go with a middle pickup?! No idea...
Here are a few guitars I made with 3 humbuckers.
BKP Rebel Yell set with a Blue Note in the middle
Custom set by AxesRus, with a true singlecoil in the middle (not a p90!)
Three singlecoils by House of Tone. I hate these pickups; I just don't like singlecoils!
BKP Silo in bridge and mid (with the mid split as described above!) and a VH2 in the neck. This axe is... like a wherther's original. Hard, heavy and sweet.
This axe is insane. Purpleheart top, bastogne walnut back, ebony neck. Pickups by ToneforDays. Do they still exist? No idea! Bridge and neck are based on the 59/custom hybrid and 59/Jazz hybrid respectively, but with alnico5 slugs and alnico8 bar underneath. The middle is, you guessed it: two singlecoils.
Dutch Beech top on chestnut, with Dutch maple/sycamore neck with Dutch walnut fretboard. JB/Fullshred hybrid bridge, Jazz/Sentient neck, and a pickup I can't remember in the middle.
Single piece flamed maple top on single piece Honduras mahogany back, with a single piece purpleheart neck. This axe weighs as heavy as it looks. Three Bill Lawrence pickups. They don't make those covers; I made them, to shield my eyes from their horrid look. Seriously, they're ugly. But the tone... Yup, that's there. But I can't handle the look, so these pickups will have to go.
HSH Setup in a an Ash LP with a maple neck, trem, and a 25.5'' scale. This thing sounds like. Yup, a les paul. Not a strat. Not a tele. Les paul. To my ears anyway.
I forgot about this one. F-Holes, fully hollow, nice top, sunburst, lovely slim neck (too slim for my taste).
Oh, boy. A 21mm thick ash body with a 21mm thick maple top. A baseball bat style neck (5 piece walnut and flamed maple), with a 25.5'' scale, trem, HSS setup. This baby sounded like nothing else. I thought it might go into stratty territory but it didn't work out that way. Only for the best.
Pffff.... This guitar. My friends, this guitar is it. This. Is. It. Nothing else even thinks it's able to compare. It's got a single piece flamed maple top on single piece Honduras mahogany back, but with a 9 piece ebony/cocobolo neck. No inlay, no binding. Nothing of the sort. Just a sunburst finish and three custom Seymour Duncan pickups. Bridge and neck are the Joe Bonamassa pickups and the middle is a customized Phat Cat. Out are the two alnico2 bars and in are 2 heavily degaussed A5 bars. The bridge pickup is in the wrong spot: 6mm too close to the neck. Once I mention it, you can't unsee it. I hate the look, but the tone. My friends... the tone. The action is insanely low, with a huge baseball bat for a neck. For all intents and purposes, unplayable for most. But, I can't play guitar if my life depended on it! :ban: So I need that low action and thick neck. The pots are the same ones I installed 8 years ago and the rest is, well.. there. The day I'll have to refret this guitar, I'll take a day off, relevel the board, install block inlay, get a laminate trim router to trim a binding ledge and install a binding. But until that day is here, this axe will remain as is.
This guitar is no more, but had the best playing neck I've ever made. Single piece rosewood. The bridge pickup went to a forum member here, the trem has been taken apart a thousand times and repositioned at least as often. The finish was worn, with worm holes. This axe had a passive/active switch, so I could switch between passive and active for the bridge humbucker. This guitar was an astounding success and failure, because it sounded and played the way I wanted it to, but didn't look the way I wanted it to. Can you see that this one is old?
I made this one for my then-girlfriend. She never played a single note on this one muahaha. What a waste... I didn't care much for the 'true' p90, for it had the same issues as the ones I discussed earlier.
I wanted a strat tone from a LP shaped guitar, so badly. I just doesn't work.