Many years ago I discovered Hotrail style pickups as a problem solver for awkward guitarists. My strat quickly gained a full sized humbucker (ie two coils sided by side wired in series, with both the coils and magnets arranged opposingly, so the motor effect is (nearly) doubled but electromagnetic noise is (almost) cancelled out). And me being me, this humbucker was seriously overwound (extra coils of wire for increased output) to a resistance of 16k (Ohm - Guitarists like to omit units, especially when they lead to odd questions, the answer being all other things being equal, more turns of wire increases DC resistance of a pickup, and is thus an indication of output, this value is small compared to the (usually) 500kOhm potentiometers used for Volume (potential divider) and Tone (low pass) controls on the guitar and compared with the impedance of a typical amplifier. For reference, the single coil pickups in my strat were approximately 4.5k which is a little low, and most off-the-shelf guitars that aren't marketed at the insane have humbuckers that are between 6k and 11k, with the bridge position needing proportionately more output as the strings vibrate less.
I then briefly owned a Washburn Mercury guitar with some very curious features, a locking trem that was almost a Floyd Rose but wasn't (and didn't really work very well), two single coil sized pickups, Seymour Duncan Hot Stacks, that were two coils stacked on top of each other around a huge ceramic bar magnet rather then individual magnets for each string (as in single coils) or a single large magnet underneath the pickup with iron pole pieces (often bolts) guiding the magnetic field through the coils underneath the strings (as is common in humbuckers). In the neck and middle position these had a DC resistance of 13kOhm which meant lots of output. They struck me as being very well balanced, without too much bottom or top, without adding much of a character of their own to the unplugged sound of the guitar and never sounded muddy no matter how far past 11 you turned the gain control of the amplifier. And string bends didn't go quiet then loud again as the string moved past the pole pieces as the magnetic filed was reasonably uniform all the way across the width of the pickup. In the bridge position was another Seymour Duncan monster named the Invader. This was completely different animal. 16.8kOhm DC Resistance, 3 ceramic magnets and large Allen headed bolts as pole-pieces, the heads of which were so large they were almost touching. These gave something of a rail effect in that it really didn't matter where the string was over the pickup. However where the rails screamed and wailed this thing just growled. It had it's own distinctive voice and leaves little of the character of the guitar in the sound. There's not a lot of top end and intricate parts become muddied even when played with very little distortion. Great for bashing powerchords and palm mutes on, and great for hiding mistakes. Just after I bought this bright red 80s shred machine, Blink 182's Tom Delonge signature Fender was launched, sporting a single Invader in the bridge position, a volume control and nothing else. It sold like hot cakes and inspired many imitators. I quickly fell out with that guitar becasue it didn't stay in tune, and each pickup had a separate On/Off switch, with the invader having a On(Both Coils)/Off/On(Single Coil) switch, so a mid song change to the neck pickup for a bit of wailing was fiddly and annoying.
I swapped that guitar for a bass and started pushing the guys I was making music with to actually get a gig somewhere, but we had a problem, our guitarist's prized Fender Stratocaster had single coil pickups, and we played grunge. Or we did when there wasn't too much electrical noise. I was told I couldn't cut holes in the guitar like I had on mine to fit a humbucker, so I went looking for a Hot Stack, and began failing. It seems they weren't popular at the time. What were popular were Hot Rail style pickups, although the Syemour Duncan product has a different voicing to the other models I've tried, the DiMarzio Chopper and Fast Track 1 sound closest to the sound I associate with this style of pickup. These designs have two coils side by side, with a blade through the centre of each, so they're laid out like a standard humbucker, but have rails and fit into half the space. One of our local guitar stores had some unbranded (probably Artec, someone suggested Gotoh) in stock at a reasonable price, and this cured our hum problems and convinced me to try a 15.9kOhm monster of a pickup in the neck of my strat as it was a drop in replacement, no carving of scratch pates and and gouging of wood. It was a little overwhelming even for my reasonably hot bridge pickup, a little glassy, very warm on the clean channel but it just begged for lots of slow wailing parts and is the only pickup I've never considered changing. Weak minded individuals sometimes attempt Run To The Hills on discovering this pickup and my amp settings.
I had a moment of weakness and bought another guitar, a copy of a Warlock. The pickups were rubbish, and I thought I'd try an Invader in it. I think the guitar lasted one gig, before being swapped for a friend's Mockingbird copy by the same manufacturer, and the Invader went in the bridge of my strat, and stayed there for years. It was quite satisfyingly menacing but I kept breaking pickup selector switches as I beat the guitar into the neck position as soon as I wanted to really play. Strats are supposed to have a middle position pickup, I removed the last of the rubbish single coils when I had a new scratch plate made for a Gibson style Neck/Both/Bridge of nearly indestructibleness and just the hotrail and the Invader.
I then found a DeArmond M55, which had just one (stock, 9.8k and weedy sounding) pickup that had a really nice neck on it and decided to rescue it. A GFS Crusader (Invader lookalike) pickup was found, but it sounded a bit different, less mud and more top end. Much more useable if I don't treat it like an Invader as it. I've previously gone on about this guitar so I won't now.
Then we needed to find new pickups for the lead guitarist for the band I was in at the time. An LTD Diamond Plate Explorer should be the epitome of thrash metal, but for some reason it was fitted with some very conservative pickups that didn't adequately torture a Marshal JCM900. A sweet sounding Seymour Duncan Jazz was chosen for the neck, as its clear, articulate, and surprisingly mid-scooped sound make for an excellent soloist's pickup. In the bridge position we chose a Seymour Duncan Dimebucker for ultimate shredding power. This is another Rail based design, like a hotrail but with two full sized coils. It's full of bite and clarity when required yet power chords and palm mutes still growl appropriately menacingly. I didn't get to play with this much as prying the guitar out of its owners hands was difficult.
Fast-forward to my next band, and I decide I'm going to get the other guitarist using his locking trem equipped Peavey that's been gathering dust for years. Once set up properly the liscenced Floyd Rose worked perfectly, but the guitar was no way near as powerful sounding as his other guitar a very well worn Ibanez equipped with ferocious DiMarzio pickups that are a symphony of squealing harmonics and low end crunch, supremely sensitive to how they're used or abused. There was the additional problem of the pole pices of the stock humbuckers not lining up with the strings properly. The string spacing on a Floyd Rose bridge is slightly wider and it looks like some cost cutting had ruined an ok guitar. I found something in a bargain basement for very little cash, similar in design to the Dimebucker, except this had much thicker rails. I think it's the Artec product that GFS market as the Power Rails. It's very articulate and responsive, but not as sterile and harsh as the Dime, but also not as tight at the low end and less scooped, allowing more of the character of the guitar through. There is much grinning like a child on Christmas morning when the guitar is handed over.
I'm convinced by all this to try a rail pickup in the bridge of my strat, so I track down a pair of what GFS market as Crunchy Rails, again for very little money thanks to the wonders of ebay. The neck pickup can go it pair the Power Rails in the peavy, and the bridge is currently in my strat, whilst the Invader takes a holiday. The Crunchy Rails are full of squealing goodness and have a tight focussed sound that matches my favourite hotrail remarkably well. Only time will tell if it stays.
I ran into a problem or 4 installing the pickup, mostly due to differing colour schemes for pickup wiring, and by following the included diagrams, you end up with something that's out of phase with Seymour Duncan wired guitars, giving a horrible squawk when both pickups are on together, I chose to re-wire the neck pickup and managed to melt the series/parallel switch, so I need to order a new one of those. And then I broke some strings and I decided to use up an old pair of 10-52 (Regular tops, heavy bottoms) when I've been playing 10-46 or 9-46 (Light Top, heavy bottoms), and I'm not sure I like it. However there is an entertaining conversation that nicely illustrates the level of giberish both guitarists and trekkies talk.
Quote:
Charles Elwood followed the polarity chart for the new pickups carefully, only to find that somewhere, something is out of phase
Greg J Preece I recommend doing it ST style - reverse the polarity, reconfigure the deflector dish and dump the warp core.
Charles Elwood I'm going to disasemble the deflector dish *again* invert the inductor, rebias the valve emulator, and engage the pinch harmonic distortion.
Charles Elwood studies internal dictionary... I suspect the increased tension of the new harmonic generators may require realignment of the warp core.
Charles Elwood Gah, the forward sensor configuration relays are fused! We can't go any slower than warp 9!