Connecting Power; Using Ac Power; Using Vehicle Battery Power - Radio Shack MPA 31 Owner's Manual

Line transformers have several connec-
tors cafled taps. The primary taps (on
one side of the transfonnner) are the in-
puts and are rated in watts. The second-
ary taps (cff) the opposite sicte of the
transformer) are the outputs and are
rated in ohms.
{SECONDARY)
Cauttons:
• Before you connect the speakers, be
ajre the total wattage of the primary
taps you intend to use does not ex-
ceed the ampfifier's maximum 20-
watt output power rating.
• Avoid multiple connections to the amp-
lifier's 70V and COM terminals.
COM 4 0 a n 160 70V
CDM 4 0 8 0 160 70V
(PRIMARY) (SECONDARY)
1. Connect a wire from the ampliftor's
TOV tenninal to the transfomner's pri-
mary tap that matches your speak-
er's wattege ratFig.
Note: Usually, eac* speaker in a sys-
tem uses the same wattage tap. If
you want a particular speaker to
have a higher volume level, use a
higher wattage tap on its transformer.
2. Connect a wire from the ampfifier's
COM (common) tenninal to the C
(common) taps on the transfomner's
primary side.
3. Connect a wire from the speaker's
positive (-F) terminal to the trans-
former's secondary tap that matches
the speaker's total impedance (4
ohms, 8 ohms, or 16 ohms).
4. Connect a wire from the speaker's
negative (-) tenninal to the C (com-
mon) tap on the transformer's sec-
ondary side.
CONNECTING POWER
You can power your amplifier from stan-
dard AC power or from a 12-vdt DC
power source (such as your vehide's
battery).
Using AC Power
To use standard AC power, simply plug
the suppfied AC corcl into any standard
AC outiet.
Using Vehicle
Battery Power
You can power the amplifier from your
vehicle's 12-volt battery.