But despite all that, something feels off. Tweak as you might, you can't get the low end you want or maybe can't find the clarity in the mids that you need. You know your relationship with your guitar is missing something, but you just can't imagine life without it. So what can you do?

In short, the last chance for you two may be sending your guitar under the knife and getting it seriously upgraded by changing the pickups.

To be certain, there is possibly no more drastic maneuver and nothing that will affect an electric guitar more than altering the electronics. At the most basic level, the very character of the instrument is defined by the wood body and the magnet inside the pickups; altering the body will affect tangential sound properties like its sustain, but changing the electronics will almost turn it into a new guitar.

Compounding the problem is the sheer number of options in pickup configurations and how wild of a sound alteration you're willing to make. For example, taking a run-of-the-mill Stratocaster and fitting it with a pair of EMG active pickups can effectively render one of the de facto standards of country music playing into a squealing death metal machine. A converse swap of EMGs to Dunlops in a Les Paul can morph the average gunslinger's weapon of choice into an accidentally tasteful jazz guitar. So how does a person choose, and what exactly needs to be done once the replacement parts have been selected?

The general guideline is to know in advance what kind of sound you want your gutted instrument to have. Something heavier? Cleaner? Louder? Most guitars are fitted with very tame electronics at the factory, but it's important to note they're chosen for the simple reason of their complementary relationship with the body they're housed in. While the simplest route may be to merely acquire a higher-end version of those pickups, this will usually only result in a more extreme version of the sound you already have.

Much like many guitarists do when they first pick up the instrument, try researching gear used by musicians whose tone you're trying to borrow from. Guitarists of any fame often have dedicated technicians with elaborate installations, but the general idea isn't impossible to research and at least slightly recreate (one exception to this is U2's The Edge; legend says he and his technician are the only two people on earth who know both the guitar configuration and rig settings for the tone on "Mysterious Ways").

Tone issues aside, the biggest decision you need to make around swapping pickups is the choice of installing active versus passive pickups. Active versus passive refers to how the magnets are actually powered; "passive" electronics create the magnetic field by virtue of having a magnet at their core, while "active" electronics actually receive an additional boost from an attached nine-volt battery. This boost creates a wider magnetic field, which in turn creates a louder tone useful in heavy distortion, and is a big part of why active pickups are the weapon of choice inside the guitar of many of the gunslinger guitarists of heavy metal. This boost, however, also provides a wider response at the top end and has made active pickups a favorite of jazz players as well.

Active pickups, of course, will require a more complicated installation to make room for that battery inside your guitar's body, as well as extra room carved out to ground the current inside the instrument. (They'll also require you to remove the instrument cable from the guitar when you're done, as the completed circuit will drain the battery even when it's not being played.) This creates the veritable paradox of active pickup installation: your sound will be pushed almost to another level, but you run the risk of irreversibly damaging the way your guitar handles the sound it produces.

This also leads to the other crucial decision about the overhaul of your guitar: how to handle the installation. While it's entirely possible (and superficially not that difficult) to install them yourself, this is only recommended if you have at least some soldering experience and a thorough understanding of pickup positioning relative to the rest of the guitar body. For example, with the new sound your guitar creates and the more powerful magnet at work, you may need to have the bridge raised or lowered to avoid overloading (or possibly increase the strength) of the signal sent into the pickups. So although dropping new pickups into the instrument is relatively easy, ensuring you can fully exploit their capabilities is usually an endeavor best saved for luthiers and professionals.

Let's say you have a Les Paul with which you play fairly straight-ahead pop and rock, but you decide you want a little more thump in your guitar sound. You know that your amplifier can only work with what it's given, so you decide it's time to change what sound your guitar is sending it. You opt for those active pickups – we'll say you chose the EMG 81 and 85 combination, a fairly standard pairing – and get to work. You remove the back panel from your guitar and get all the existing electronics out of there.

Since you chose active pickups, your old electronics are useless now anyway; the potentiometers ("pots") already in place don't put up enough resistance in the volume and tone knobs to truly control the strength of the signal that will come out of those new pickups, so you pack the whole old setup away. You carefully drop in the new pickups, wire the new circuit together using a very low-wattage soldering iron (40 watts maximum to avoid burning through both wiring and body) and some high-quality rosin-core solder (something in the neighborhood of a 60% rosin compound), and screw the jack back in place. The battery is safely nestled in place, and luckily there was enough room in the guitar body to avoid any major surgery.

With everything in place, you plug in for a test run and right away you can hear the difference, but suddenly you may notice an unintended change – the introduction of signal noise. To create the louder and wider sound, the magnets send a hotter signal, meaning the magnets in your new pickups are much more sensitive than the old ones.

This is obviously just an example, but also not a very uncommon situation in changing guitar electronics: the result is exactly as intended, but the side-effects create new problems of their own. The joy of doing it yourself aside, the case for letting a professional do the work on your pride and joy more than makes itself, unless you're willing to gamble the time and effort needed to get all the pieces working together.

Or, depending how serious you and the old model were, if the whole thing goes horribly wrong you can always just buy a new guitar. This may sound extreme but, if you think about, is really not much more extreme than gutting the insides of the instrument you already have and changing its sound forever.