Wednesday, September 4, 2013

Guitar electronics

Today I am going to talk a bit about electronics. I can get into great detail on this subject, but I really don't want to do that. There are varying opinions on the subject of what pickups are better than others, what guitar company wires their instruments the best, and on and on.
What I do want to talk about is what makes a guitar an electric guitar. Where does the sound come from, that you hear in your amplifier, and what makes that happen.
Basically, electric guitars and basses operate on the same principle. They have pickups, controls, switches, etc.
A pickup is a series of magnetic poles. These poles could not effectively 'pickup' the sound from the strings without a few important things. Number one is a fairly strong magnet, that is attached to the poles, 6 and 12 for guitar, and 4, 5, 6 and more for basses.
Number two is a coil of insulated wire with a start and finish end.
The insulated coil wire is wrapped around the magnetic poles, and the amount of wraps vary from one manufacturer to another.
There is an elite group of pickup manufacturers in todays market, and depending on what sound you are looking for, they will custom design a pickup that is just right for the sound you want to hear from your guitar.
That, in a nutshell is what makes the sound. Again, I am not getting into detail in this blog.

So, what happens from the pickup? How does that sound get to my amplifier?

The pickups convert the sound that the strings make on the guitar to an electronic signal. Based on how many pickups you have on an instrument, this is usually routed through a switch. The switch basically sends the signal from one, two, or three pickup guitars to a volume / tone potentiometer, or 'pot'. The potentiometer varies the amount of signal that you would want to go to your amplifier on to the guitar's output jack. So when you plug your guitar into your amplifier, you can control the volume both on your guitar and your amplifier.
Potentiometers are also referred to as 'faders', because that is what they do. There are also tone, or treble / bass potentiometers on your guitar. These vary the bass / treble, or 'tone' on your instrument through a small capacitor. On some guitars, there are either one, or two tone controls, and the same is true of the volume controls.

By raising and lowering the pickup, either closer to, or further away from your strings, one can add a lot of colour and tone to your 'sound'. There are factory specs for Fender, Ibanez, Gibson, PRS and many more. But ultimately you are the one that has to decide what sound your are looking for from your instrument.

Some pickups require an 'active' circuit, by means of a small on-board pre-amplifier. These Pre-amps are usually powered by the use of a 9 volt battery, which, like the pre-amp, is installed in the control cavity of the guitar.

Acoustic guitars can also be amplified by use of a pickup. Newer acoustics utilize 'piezo' technology. A 'piezo' is a tiny pickup that is designed to pickup vibration and resonance, as opposed to a magnetic signal.
Some of the new manufacturers of acoustic pickups have gotten incredibly good at making an acoustic sound amazingly like it should sound 'acoustically' by means of the use of these pickups.
The piezo pickup is also operated on battery technology, or 'phantom' power. Which, in simple terms is power that comes back into the instrument from an external device, like a DC power supply, sound board, or a digital interface.

The Gibson guitar company features a PAF (patent applied for) pickup on their guitars. These are also called humbucking, or balanced pickups. They are basically two single coil pickups that utilize two different magnets. The magnets are mounted in such a fashion that their respective poles attract (North-South and South-North) On the 6 string models, they feature 12 individual poles and on most PAF's one set of poles is covered by the chrome pickup cover. It is debatable as to whether or not the pickup cover is really required on these, and on some models it is dis-attached from the pickup.

Fender pickups, for the majority, have always been single coil. That just works for them. Like Gibson, and so many others, Fender has always maintained an 'if it ain't broke....' approach to their guitars. They may have changed their guitar designs and colours a bit, but their basic pickups are still the same.

Bass guitar pickups are built much the same as their electric 'cousins' but are usually overwound to better re-produce the lower frequencies of those bass notes. Basses also utilize both the humbucker, single coil and active designed pickups, but most of the bass guys I know prefer the simple old single coils, or active single coils. The Fender Precision Bass is still one of the biggest selling basses on the planet, and they are pretty much the same guitar they were when they were introduced in the 50's.
It's just that pickup technology has gotten so much better than the old ceramic or 'rare earth' magnets.
Newer designed magnets (Alnico 3&5) will outlast their counterparts, because the magnetism will not fade like it did on the old pickups, and as a result, neither will the tone.

Some guitar manufacturers use both humbuckers and single coil pickups on their guitars. This combination of pickups gives the player a wide range of sound. Not just volume, but different 'tonal' characteristics as well. Different pickups can totally change the sound of your guitar, and they can be an exact retrofit for your guitar. In other words, nobody will ever know but you.
I have my favourites, but again, that is not what this blog is about.

Hopefully this has given you a better insight as to how electric guitars work.

Have fun!

Brett McNaueal

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