Electronic parts. What is Under The Hood
Really, when you get right down to it, the electronic parts a Dino has to deal with when they pull the pickguard or back cover plate off their axe are all pretty basic items. This is definitely not rocket science and that's good. I don't believe Dinosaurs did any rocket building, but, I could be wrong.
When you look inside you'll commonly find wires running from the pickups to the control layout, potentiometers, switches, one or more capacitors, possibly a resistor, mounting hardware, and then more wires leading to a ground point and output jack. Hopefully you'll also find sheilding in the form of paint or tape lining the cavity as well as on the inside of the control backplate or pickquard.
While many Dinos prefer to hire techs to nose around in their electronic goodies, not a bad idea if you can afford it, others that need to save up just to buy whatever part(s) they're replacing can usually handle the basic setups on their own. Knowing how to make a clean solder connection without toasting the delicate stuff is definitely a plus. Wiring diagrams can be found at many guitar parts websites for you to download for free. Print out the ones you need for your project and keep them handy.
Picking the appropriate parts to fit your needs.
It's important to note that many of the parts you'll be dealing with come in different values or have different tolerances. Even very basic items like buying a potentiometer, pot, with the proper shaft length and diameter is important. The wrong size could result in your knobs looking like they're sporting a boner or the guitar cavity not being deep enough for the pickguard or backplate to be screwed down flush or even screwed down at all. If the shaft is to big to fit through the hole there's even more problems in paradise. Remember. Size matters.
Two types of pots are commonly available. Linear taper and audio taper. Linear tends to have a narrow band where the volume or tone level takes a major jump in one direction or the other. Audio taper sounds smoother and allows for a more precise adjustment in the way your ear will hear it. It's also important to note the value of the pot. For most single coil setups 250k pots are recommended. Most humbucker equipped guitars come standard with 500k pots. Note. In the 70's, Gibson equipped some of their guitars with 300K pots while, at the other end of the spectrum, it's not uncommon to see 1meg pots used with humbucker equipped guitars produced by current manufacturers. Basically, the higher the value of the pot the less treble or brightness will be bled off as you turn the the control knob down. Most humbuckers can't afford to lose too much treble so higher values work better.
Switches come in many different forms from toggles to sliders to blade type to push pull pot types, etc. Two way through five way switches are most common. Some have many different tabs you can solder to depending on what you want the switch to do. These can be a bit confusing. Make sure you've got a closeup schematic of the points you want to connect the wires to right in front of you.
A capacitor is used in conjuction with the tone pot. Think of the cap as the determining factor on what frequencies the tone pot can bleed off from the guitar voicing as you turn the tone knob down. It acts like a baseline. All frequencies below this line are passed on to the output jack while frequencies above this line will be slowly cut or reduced as the tone setting is reduced. Smaller caps will put this baseline relatively high so only the very high frequencies are affected. This means the pickups will retain more brightness when at the bass end of the control knobs sweep. Only the highest frequencies have been cut. A humbucker equipped Les Paul normally carries a small cap rated at .022MFD, Microfarad, while a single coil equipped Strat has a larger cap on board rated at .047MFD. This allows for a wider range of the high frequencies to be cut when the tone knob on the Strat has been turned down. Note* Not all caps are held to the same standard of tolerance levels. Caps carry a code imprinted on them that note the size followed by a letter. For example, 223M or 473K. The first two numbers identify these examples as having a .022MFD and a .047MFD value respectively. The letter that follows denotes the tolerance level of accuracy the manufacturer has allowed. The further along the alphabet the higher the tolerance level. See the table below.
F equals a tolerance of +/- 1%.
G equals a tolerance of +/- 2%.
J equals a tolerance of +/- 5%.
K equals a tolerance of +/- 10%.
M equals a tolerance of +/- 20%.
Both Mallory and Sprague Orange Drops normally carry a J. +/- 5%. Most caps found in brand name guitars carry a K or an M or worse.
You'll sometimes find a small resistor used in conjuction with a cap on the volume control. This is usually done as an upgrade on a modded circuit. It reduces the amount of treble loss when the volume knob is turned down. Lower volume settings don't go all murky sounding.
As with the size of pots and pot shafts output jacks come in quite a few different sizes and shapes. Other than choosing between brand, shape, size, and mono or stereo they all carry out the same function. Mono jacks can only be used as a mono output while most stereo jacks can be wired for mono or stereo output.
Wire types commonly used include shielded or unshielded, braided, cloth covered, etc. Shielded wire, just like shielding the cavity with aluminum or copper tape, will contribute to a reduction in hum or buzz .
That's about all you should find if you look inside your guitars control cavity. I picked up a used modded strat once and found what looked like a piece of a roach in there, but, the stoner who did the mods did a really good job, so, what the hell. It's a Dino world. We're usually too busy playing to take much time to sit in judgement of each other.