The alnico V humbucker is the sound of rock
Let's talk about the most ballsy alnico humbucker pickup, the V.
It should be noted first that when you want the absolute most output available from a humbucker pickup, you go with a ceramic magnet. The old school way of this is the DiMarzio Super Distortion DP100 model. That pickup, while not the best with its treble response, is the original from the early 1970s that's still made new today. This is the pickup that has the old school rock sound. Yes, there are many other "hot" pickups now, but the original that's got the balls, so to speak, is the DP100.
Then there's alnico magnet pickups, and that's what I'm going to talk about.
For those not aware, alnico means magnets made from ALuminum, NIckel and CObalt. The most generally available alnico magnet strengths are 2, 3 and 5 (there is also 4 and 8, but those are not-so common). Sometimes these numbers will be shown as roman numerals II, III and V. A higher number means a greater magnetic pull and usually greater output overall.
With Stratocaster guitars, the two most common types of alnico are 3 and 5. The 3 is weaker but brighter. The 5 is stronger with greater midrange response, but has less brightness. Some prefer the 3 because of the clearer "bell-like chime", but I prefer the 5 on the Strat.
For guitars with humbuckers, the two alnico types you see most are 2 and 5. I prefer the 2, but the Alnico Classic PRO pickups have alnico 5 magnets, which usually means "hot" output.
I'll describe the bad of this and then the good.
I've been having to go through all my amp presets (I have a Line 6 Spider V 60) and adjust them to accommodate the higher output of the Alnico Classic PRO set. This has been an annoying process, because I had all my stuff set to pickups with medium output. It's not the end of the world that I've had to do these adjustments, but still, kinda annoying.
Because the pickups are alnico V, they're both hot and trebly at the same time. On a Strat, I could deal with this because Strats are always trebly and it's expected. But on a Les Paul or like guitar with the same pickup set I have, it's not expected.
Having hotter output pickups means I've been able to cut back on using compression quite a bit, and sometimes eliminate it entirely. This is a welcome thing because it means the guitar is more usable in more situations.
The hot/trebly thing was unexpected and somewhat annoying, but it's also a good thing for basically one reason. Better to have too much treble response than not enough. Too much treble? Dial back the tone control; that's what it's there for.
There is also one gigantic major advantage of having a pair of humbuckers with alnico 5 magnets:
It is the classic Les Paul rock sound.
As I've been experimenting with my guitar, getting used to the pickups and so on, I could hear rock sounds of the '70s, '80s and '90s come out prominently.
When the distortion is kicked in, this is That Guitar Rock Sound from a lot of famous rock bands I heard from decades ago. I could hear Def Leppard, Guns 'n' Roses, RATT and many others from that wail of the bridge-side humbucker at full volume.
It's basically the same thing that happens whenever I play a Strat with pickups that have alnico 5 magnets. On that guitar, when the magnets are alnico 5, I hear famous Strat sounds. Stevie Ray Vaughan, Mark Knopfler, David Gilmour and so on...
...but on the 'Paul with the alnico 5 magnets, I hear the famous rock tones. This is a sound I definitely did not get out of my Ibanez guitars with their ceramic magnet pickups.
Alnico 5 humbuckers like to be driven
I'm not a high-distortion type of guitar player, but the 'Paul with the alnico 5 humbuckers really, really likes it when played overdriven or distorted.
This isn't to say I started playing metal again, because I haven't. But I have started toying around with rock and hard rock tones again since the guitar likes it so much.
Even something as simple as old school distorted power chords really rings out true with pickups that have these particular magnets in them. It just works.
Would this work in a non-Les Paul guitar?
Yes. It's not so much the 'Paul itself but rather a pair of genuinely decent alnico 5 humbuckers that's really making the difference here.
I'm not saying that alnico is any better than ceramic magnets. It's just different.
I have played some crazy-good guitars with crazy-good sounds that come from ceramic magnet pickups (like the Mexico made Fender Strats of the '90s and 2000s), but in this instance, my 'Paul totally has that classic rock tone to it, and it's because of the alnico 5 humbuckers.
The closest equivalent to what's in my 'Paul would be the Seymour Duncan '59 set. The voicing of those is pretty much the same as in my 'Paul. Classic rock tones kicked up a notch from the alnico 5 instead of lower output alnico 2.