Depending on the value of the
component, resistors block electrical current. This is exactly what
potentiometers do as well, but those have a variable level of resistance.
Consequently, these are sometimes referred to as "fixed resistors."
These are only applied in a limited
number of applications in most guitar circuit. For example:
- A high-value resistor is placed between the string ground and the guitar's
output to prevent a guitarist from being electrocuted if the amp's ground
is somehow interrupted.
- A resistor can be added between the volume knob and the ground to increase
the brightness (and even the overall signal output) by blocking part of
the signal normally lost to the ground.
Commonly refered to as "caps,"
these store a small amount of charge, but in various guitar circuits, tey
are used to alter a tonal range. Some example applications include:
- A capacitor is usually soldered between the tone knob and the ground,
and this sets which
- A rotary switch is used to select between a variety of caps in
order to selectively pull out and accentuate particular frequencies.
Switch - A simple type of a Varitone consisting of just two caps.
These are most commonly (read: almost exclusively) found on Gretsch guitars.
Cap codes: Some additional useful information.
- A very small gauge cap is attached in parallel to the volume knob to
prevent the high frequency components of the signal from being selectively
cut when the volume is turned down.
To read the value on a capacitor, you need
to understand that the first two digits are multipled by the number specified
by the third digit. Use the following code, and the value will be
given in pico-Farads:
For example, if a capacitor says 223 is 22
with 3 zeros or 22,000 pF which is otherwise referred to as a .022 uF capacitor.
Additionally, there is sometimes a letter
representing a tolerance code. For example, J stands for a +/-5%
These store electricity in a magnetic
field,. They are occasionally found in applications such as custom
passive tone controls. For example, many people include an inductor
between a varitone and the ground of