b. Control Locations.
(1) Program Selector Switches. The program selector switches are located directly above
each pot and regulate the direction of the channel into either the audition or program amplifier. There
are three positions for the program selector switch and they are: left for audition, center for neutral, and
right for program.
(2) Tab Key Selector Switches. The tab key selector switches, which are located above each
pot and program selector switch, are used to simply select a particular input to the pot.
(3) Microphone Channels. The microphone channels are made up of Pots 1, 2, and 3.
Through the use of the tab key selector switches up to 12 microphones can be put into the three pots at
(4) Turntable Channels. The turntable channels are made up of Pots 4 and 5. Four upper tab
key selector switches above each pot select the turntable input to be used.
NOTE: On pots four through 10 (fig 2-20) there is an extra position on the pot itself,
below the zero mark, which is called the cue or detent position. This cue position
connects any input to the pot to the cue amplifier and allows for the cueing up of the
(5) Tape Channels. The tape channels are made up of Pots 6 and 7. The tab key selector
switches above each pot are used to select the tape channel input as with the turntable channels.
Learning Event 3:
DESCRIBE MICROPHONE CHARACTERISTICS
Introduction. Up to this point, you have learned about sound as it is heard in the form of
acoustical (sound) energy. With the use of a microphone, we convert acoustical energy into electrical
energy. The microphone becomes the first link between sound as it is heard in varying forms of air
pressure, and its permanently recorded forms of tape, disc, and film. Almost any recorded material,
such as voice, instrument or special effects, must first pass through a microphone. In the following text,
the basic construction uses of microphones, the five types of microphones, their general and specific
characteristics, and their uses will be discussed.
Principles of Operation. A microphone (electracoustic transducer) converts sound energy into
electrical energy. Physical structure for all microphones includes a housing, diaphragm, magnetic field,
and a moving part within that field according to their principles of operation. Microphones break down
into two categories.