Yamaha KPA-502 Owner's Manual page 6

Connecting speakers
Connect the SPEAKERS terminals to your speakers with
wire of the proper gauge cut as short as possible. If the
connections are faulty, no sound will be heard from the
speakers. Make sure that the polarity (+ and – markings) of
the speaker wires are correct. If these wires are reversed,
the sound will be unnatural and will lack bass. Do not let
bare speaker wires touch each other and do not let them
touch the metal parts of this unit as this could damage this
unit and/or speakers.
÷ Use speakers with an impedance of 6 ohms or more.
Using speakers with an impedance of less than 6
ohms may result in malfunction or damage to this
amplifier.
÷ Do not connect more than one pair in parallel to this
amplifier.
1
Press down the tab.
2
Insert the bare wire. [Remove approx. 5mm insulation
from the speaker wires.]
3
Raise the tab to secure the wire.
Black: Negative (–)
R
Red: Positive (+)
1
6
L
3
2
Connecting the AC OUTLETs
This unit is equipped with two UNSWITCHED AC OUTLETs
for connecting the power cords of other components to this
unit.
The power to these outlets is not controlled with this unit's
POWER switch. They will continuously supply power to any
component connected to them.
The total maximum power consumption of components
connected to these outlets must not exceed 100 watts.