Guitar Pickups: Guitar Electronics Simplified

I tried to list all the variables in making a pickup as well as what they do and how they function.

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Pickups, so called because they "pick up" the vibrations of the strings, are electromagnets. They are made of a plastic bobbin with 6 metal slugs, very fine 42AWG wire wrapped around it ranging from 3,000 - 20,000 times, a magnet underneath the bobbin and then shielded. They make the biggest difference in sound and are the most expensive guitar electronic to purchase. 

The number of times wire is wrapped around the bobbin determines the intensity of the magnet field. This creates different types of pickups made for certain genres of music. A more relaxed style, which would want a softer tone for a classic sound, would have under 10,000 wraps of wire. However, metal guitarists would prefer upwards of 18,000 wraps of wire because it creates super high gain used in metal. By adjusting the amount of wire, you can adjust for what sound you want. 

Different types of magnets are used in the pickups. Alnico and ceramic are the most common with a Hybrid sometimes used. Alnico magnets are divided into three types. The II, III and V are different alnico magnets. The II is a middle ground between the III, which offers a softer tone having the least pull, and the V, having the most aggressive pull. Ceramic magnets has a very thick tone which creates a full sound. The Hybrid is a signature pickup with an Alnico V and a Ceramic magnet.

Another big difference is made when using either a single coil or humbucker pickup. A single coil is, as the name implies, a pickup with one spool of wire. They have a relative clean sound, producing a trebly output with very little bass. The most common guitar manufacturer that uses these is Fender. Many country guitarist love the "squeak" of the Fender Stratocaster and Telecaster obtained by using single coil pickups. In contrast, a humbucker has two spools of wire. They have a very hot output, with much bass and very little treble. It's easy to get a crunchy sound from humbuckers even when your amp is set for a clean channel. Gibson is the big name mainly associated with using humbuckers. Generally, people use these for rock style music. Both are great, but neither could do the job for everything. Ultimately, it's about your preference which is most influenced by your fellow peers and guitar icons.

Pickups can be either passive or active, passive being more common and cheaper. Passive pickups receive their power through the amp via the input cable. When the amp is turned on, the electricity flows through the pickup to create the magnetic field. However, active pickups require a battery to power the pickup. They have a lower output so it uses the battery as a preamp to boost the guitar's output signal. When you plug the cable into the guitar, the battery automatically turns on the preamp, pickups and all. To shut the battery off, you simply unplug the cable from your guitar's input jack.

Shielding is the final step to complete the pickup. You shield it to prevent unwanted buzzing produced by UV Rays hitting the magnetic field. Generally, wax is used for cheap ones and the more expensive ones have either a spray or some type of tin foil like paper. Without this, they pickup more than just the string's vibrations.

Pickups make a world of a difference in the world of guitar electronics. They are the single most influencing thing on the sound and tone of your guitar. In order to obtain your desired sound, you have to choose the correct style of pickup. With many variables, you must do some research to get an idea as to what you would want. Always, always play a guitar with the pickups you want before buying them.

9 comments sorted by best / new / date

    You did explain the basics pretty well, but I have a few complaints. First of all, there were some grammatical errors and misspelling in the article, which isn't a big deal but it did make it sound less convincing. I'm also under the impression that there are more than three types of alnico, I thought that they range from I to VII. I don't really get what you mean by "the hybrid is a signature pickup". Like, whose? I know that Misha from Periphery uses alnico V/ceramic hybrids, but I doubt that you meant him, and I think that there are other such hybrids out there. It was just a weird statement. It's also not as simple as "humbuckers are hotter", an active single coil can easily be more aggressive than a vintage humbucker. But yeah, I guess that generally speaking humbuckers are hotter. And remember that the pickups are the second most influencing factor on your tone, right after the amplifier.
    The active/passivem part is all wrong. First of all the instrument cable is strictly one way, the amp doesn't power anything and the only signal in the cable is the guitar signal to the amp. The passive pickups simply don't need any electricity to work. Instead the string vibrates when played, which alters the magnetic field and the alteration in the magnetic field induces a current in the coil. Secondly, active pickups don't have a lower output, they simply make use of the battery to boost the output even more. It may however be that manufacturers don't use as many windings in the coil because it saves them time and they don't need to since the battery does the work that those, say 2000, wraps of wire would've done instead.Actives don't need to have any preamps at all really, you can just put the 9V straight into the coil which increases the power of the magnetic field, resulting in a higher output. An active guitar doesn't necessarily have active pickups either, it can just have an active EQ or some other cool stuff that has nothing to do with the pickups.
    actives were born of the desire to run fewer windings to have less field to pull strings out of intonation when super low action was desired for jazz players. It is nothing to do with saving time or any other resource. The battery is required to fuel a preamp circuit to drive the signal from pickup (much lower in strength than a normal passive) into preamp to bring it up to an appropriate level for your amplifier to recieve.
    Appreciate all the feed back. Not too sure with the magnets. I don't know much about them. That's just what I've resd. As far as the active pickup thing, I learned what j30max said. That's what I've been taught.
    I have a hum single single loaded Strat pickguard with a wiring problem. All pickups work fine and the selecter swich positions relate to the right pickups, however, there is no tone variation on any pickup. Neither tone control does anything. Any ideas?
    Do you have tone caps on the tone pots? I recently redid all my electronics in my SG, but I had to wait for tone caps. Without the tone caps, it made my tone pots practically useless. That's the first thing that comes to mind.
    I just saw this and I must comment on a few items: 1) A pickup's magnetic fields come from the magnet, as the name indicates. The number of coil turns only affects the strength of the electrical signal that is produced when the string drags the field around them. The pickup is the signal source. 2) The amplifier does not put current through the pickup (hey, it might even work to try it, but it is not the way they operate). The only source of current is the energy from the electrical signal generated by the pickup. 3) Shielding is metal wire braid around the center conductor of the cable to prevent external electric field interference from getting into the signal produced by the guitar's pickups. UV (which is light energy) does not have anything to do with creating guitar noise. 4) Wax is added to prevent acoustic vibrations (from the volume in the room)from making the coils move, which causes signals to be generated acoustically (it is then called a "microphonic" pickup if it suffers from that). Wax is not a form of shielding. 5) Single coils pickups have lower inductance (about half) compared to humbuckers, and they detect a relatively narrow region of the string vibration. Both of these give them the higher frequency response and make single coils sound brighter and 'thinner'. Humbuckers sacrifice some of the high frequencies (averaging out a larger section of string length in their detection of string movement and having twice the inductance) in favour of rejecting the external electric and magnetic field noise, and they give a stronger signal output as a side-effect, which makes them attractive to metal players who want more amplifier overload.
    "Actives don't need to have any preamps at all really, you can just put the 9V straight into the coil which increases the power of the magnetic field, resulting in a higher output." This statement is not accurate. ALL active pickups have built in pre-amps. The battery doesn't even touch the coils in the circuit, it powers the pickup's on-board pre-amp which the pre-amped signal is then sent to the amp at line level/low impedance. If the coil was being powered it would create an electro-magnet out of the pickup and there would be a large amount of pull generated on the strings. not to mention you'd go through batteries like mad.