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POTENTIOMETER
A potentiometer, or pot, is a variable
resistor. This means as the knob shaft
is rotated, the DC resistance
will change. There are three
lugs or soldering terminals on a
conventional potentiometer. The
outside two are the ends of the
resistive strip, and the center lug
is connected to the “sweeper.” The
sweeper allows you to vary the DC
resistance relative to its position along the resistive
strip, or relative to the outer
two lugs.
Potentiometers come in
two varieties, linear-taper
and audio-taper. The linear-
taper pot’s taper works at a 1:1
ratio. Audio taper, has a special
logarithmic ratio.
Audio taper is used because our ears don’t hear
changes in volume in a linear fashion as you might
expect. As the volume increases, a greater change
in signal or sound-pressure is required to perceive a
smooth transition.
LED
LED stands for Light Emitting Diode,
and functionally LEDs are very similar to
regular diodes. LEDs are most often
used as indicator lights in pedals. They
are polarized just like diodes and
electrolytic capacitors and must be
installed in the correct orientation to
work. The positive (anode) lead of the LED
will be longer and the anode side of the
LED housing will be round. The negative
(cathode) lead of the LED will be shorter
and the cathode side of the LED housing
will be at. LEDs are mounted inside
of a bezel, which protects the LED and
insulates the leads from shorting against
the enclosure or any internal components.
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