Yamaha 150 Controls and Functions

Controls and Functions

POWER

SIGNAL CLIP SIGNALCLIPPROTECTION

CH A CH B

ON OFF

1POWER switch and indicator

This is the main POWER switch. Press to power ON

the amplifier. Press again to power OFF. The POWER

indicator lights up when the amplifier is powered ON.

2SIGNAL indicators

These green LED indicators light up when the

respective channel’s output signal exceeds 4 Vrms.

3CLIP indicators

These red LED indicators light up when the respective

channel’s output signal distortion exceeds 1% (i.e.

clipping). Output signal clipping is usually due to

excessive input signal levels.

4PROTECTION indicators

These LED indicators light up to indicate that the

protection circuit is working. The speaker system is

disconnected from the amplifier outputs and no sound

is output from the speakers.

The protection circuit is activated in the following

situations:

• When the amplifier is powered on:

The protection circuit is activated for approximately 3

seconds when the amplifier is powered on. After 3

seconds, the protection system is deactivated auto-

matically, and the amplifier is ready to use.

• If a DC voltage is present at the amplifier’s

outputs:

If the DC voltage problem is corrected, normal

amplifier operation resumes.

• If overheating occurs:

Turn off the power to the amplifier to cool down the

unit and consult the Precautions section of this manual

to improve the vent condition, if necessary. Turn the

power on to the amplifier after it cools down.