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.pickup.construction...
Several different types of pickups are fitted to guitars. Pickups allow the sound of the guitar to be amplified -
 | magnetic pickups - fitted to the vast majority of electric guitars |
| piezo pickups - mostly used on electro-acoustic guitars |
| microphonic pickups - mostly used on acoustic guitars |
| special sensors for triggering, pitching and enveloping synthesisers |
The BluesHawk has magnetic pickups - here's how they work...
A magnetic pickup takes a small amount of the energy of a vibrating guitar string and converts it into a tiny electric current. A magnetic pickup is a small electrical generator.
first things first
Every magnetic pickup has two essential elements -
| a coil of fine electrical wire |
| a magnet or magnets that produce a magnetic field that surrounds the coil and the guitar strings |
Guitar strings are made of a material, e.g. steel, which changes the "shape" of the magnetic field around the magnet in the pickup - this also means - the strings become "magnetised" and are attracted to the magnet.
a bit of theory
When a wire (a conductor) moves through the field produced by a magnet, a small electrical current passes through the wire - and, vice versa - if there is movement in a magnetic field around a stationary wire, a current will be created in the wire.
The reason why there is this relationship between magnets and electricity is almost impossibly hard to explain - so I won't even try.
the real world
In the case of a guitar pickup -
| "the wire" is actually a coil of wire |
| the movement in the magnetic field is caused by the strings vibrating and disturbing the field surrounding the pickup. |
The movement of the strings/magnetic field produces a tiny electrical current in the wire of the coil, and because there are lots of turns of wire in the coil, the effect is multiplied. Despite there being many turns of wire in the coil the "amount" of electricity produced by guitar pickups is very small - it's the amplifiers job to make that small amount of electricity into one that is large enough to drive a loudspeaker.
can pickups be made more powerful?
In theory the more powerful the magnet, and the more turns of wire in the coil, the more current flows and the more powerful the pickup. But, things are not that simple -
| the more powerful the magnet, the more it "pulls" at the strings and stops them vibrating effectively and... |
| the more turns of wire in the coil, the longer the total length of wire, and the more electrical current is lost on the journey through the wire - this effect is caused by electrical resistance/impedance. Increasing impedance and resistance in a pickup not only affects the amount of output, but also the tonal quality of the output. |
So making magnets ever more powerful and coils ever fatter, in pursuit of more powerful pickups, is ultimately self-defeating. Another problem with powerful magnets is that they can change the pitch ("tuning") of a string - these effects known as "wolf-tones" are common on the lower strings of Strats if the pickup is raised too close to the strings. BluesHawks are subject to "wolf-tones" if the neck pick-up is raised too high.
single coil pickups - as fitted to the BluesHawk, Strat and Tele - are just that - magnetic pickups which have a single coil of wire in them.
Unfortunately (in this case) any coil of wire acts like a radio aerial/antenna and picks up all kinds of stray interference -
| radio signals |
| interference emitted by computers and monitors, and light dimmers etc. and especially... |
| interference in the form of "hum" given off by mains electricity, from cables and mains powered devices - for example guitar amps |
So - guitars with single coil pickups tend to be noisy - that is, they pick up a lot of interference that competes with the bit guitarists are interested in - the sound of the guitar - enter the humbucking pickup - developed by Seth Lover working at Gibson in the mid-fifties. Other anti-hum techniques are available, which include the use of a dummy coil as employed in the BluesHawk.
the blueshawk has worked hard to make this description straightforward - did you understand it? - let the blueshawk know...
coming soon...
| humbucking pickups - why they buck hum - and why they sound different |
| dummy coils - what they do |
| how tone controls change the sound |
| how the varitone works |
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