INTEGRATED CIRCUITS
Integrated circuits are complex,
tiny, self-contained collections
of components that contain
a complete circuit. Op-amps,
audio processors, and linear
voltage regulators are three
kinds of integrated circuits.
TRANSISTORS
Transistors are
used to amplify
electrical signals.
The have a flat
side and a round
side. The location
on the circuit
board also has a
round side and a flat
side. Match the orientation
of the component to this outline.
UNDERSTANDING ELECTRONIC
COMPONENTS
DIODES
Diodes are used where you want electricity to flow
in only one direction, such as power rectification,
and also to limit how much current can flow, to
create “clipping” distortion.
Diodes are also polarized, so they need to be
installed in the correct orientation. The stripe
around one end marks the negative (minus) lead of
the diode. On the circuit board, the printed outline
of the diodes also shows this stripe. Install each
diode so that its stripe matches the direction shown
on the circuit board.
2n2J630
TL072
PT2399
PT2399
PT2399
PT2399
echo audio
processor (1)
#7490
TL072CP
TL072CP
low noise
op-amp (1)
#7444
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 flat. LEDs are
mounted inside of a bezel, which protects
the LED and insulates the leads from
shorting against the enclosure or any
internal components.
