Yamaha PROFESSIONAL PC1602 Operating Manual page 4

FRONT PANEL
YAMAHA
PROFESSIONAL
POWER AMPLIFIER
CLIP
SIGNAL SIGNAL
THERMAL
M = =
PROTECTION
Q POWER Switch/POWER indicator (Red)
Pressing this switch turns power to the amplifier ON and
causes the power indicator to light. Pressing the POWER
switch a second time turns the unit. OFF.
Q Thermal Indicator (Red)
This indicator lights when the force cooling fan is operating.
Ө PROTECTION Indicator (Red)
Lights for approximately 6+2 seconds after power is
switched on, indicating that the protection circuitry is ac-
tive. The speaker outputs are shut off while this indicator
is lit. If the protection circuitry is activated for any reason
during amplifier operation, the indicator will light and the
speaker outputs will be shut off. Once the cause of pro-
tection activation has been remedied, normal operation
will resume automatically and the protection indicator will
go out.
CHANNEL A
DES
CHANNEL B
don aS d
Q Input Attenuators
These attenuators adjust the sensitivity of the respective
amplifier channel in 31 steps. Attenuation in the fuily
clockwise position is O dB, and о in the fully counter-
clockwise position.
(
Q CLIP Indicators (Red)
The CLIP indicators light when output distortion of the
respective channel exceeds approximately 196. This indi-
cates that the amplifier is clipping due to excessive input
signal levels.
Q SIGNAL Indicators (Green)
The SIGNAL indicators light when output level of the
signals is 2 V or more, in the range of 20 Hz to 20 kHz,
for confirmation of input signal.
o9 Knob Lock Adaptors (Supplied)
The Knob Lock Adaptors prevent accidental alteration of
attenuator settings once the appropriate settings have
initially been made. How to install Knob Lock Adaptors:
pull out the Input Attenuator Knob to insert the Knob Lock
Adaptors into exactly the same place.