Control Elements - Alto MC250.4 User Manual

3.

CONTROL ELEMENTS

3.1 The Front Panel
2
MC250.4
PWR ON
ON
LEVEL
16
12
OFF
POWER
CH1
1
1 Power Switch
It switches on / off MC250.4 main power.
2 Power LED
This LED lights up when the amplifier is powered on
Input Level Indicator Display
3
There are three high accurate LED indicators, which shows the level of the input signal. When the respective
channel's output signal distortion exceeds 0.5%, the red LED (clip) indicator lights up. it will warn you that the
level of the input signal is too high and may cause distortion, please attenuate the level of the input signal.
4 Protection LED
This green LED indicator lights up when the amplifier is powered ON, indicating that the soft-start protection
system is working. No sound is output during soft-start up. if one of the protection systems is activated during
normal use, this indicator lights up and no sound is output. The speakers system is actually disconnected from
the amplifier outputs when this indicator lights up. The protection systems are activated when overheating
occurs or a DC voltage is corrected, the protection systems deactivate automatically, this indicator goes out, and
normal amplifier operation is resumed.
Output Limiter LED
5
Set the clip limit switch at "ON" position, the yellow LED lights up when the unit is limiting the output signal.
6 Level Control
This pot provides smooth level changes control.
7 Fan
The unit is equipped with two fans, which can accelerate the flow of air to lower the temperature inside unit. The
inside temperature determines the fan speed, which controls the inside air flowing speed.
8 Bridge Mode LED Indicator
When you operate the unit in bridge mode, the LED indicator lights up .
9 Parallel Mode LED Indicator
When you operate the unit power amplifier in parallel mode, the LED indicator lights up
3 4 5
250W 4 Professional Amplifier
CLIP PROT CLIP CLIP PROT CLIP
-10dB LIMIT -10dB -10dB LIMIT -10dB
-20dB -20dB -20dB -20dB
PAR BRDG LEVEL LEVEL PAR BRDG LEVEL
20 20 20 20
18 22 18 22 18 22 18 22
24 16 24 16 24 16 24
26 12 26 12 26 12 26
6 28 6 28 6 28 6 28
30 (dB) 30 (dB) 30 (dB) 30 (dB)
CH2 CH3 CH4
6 8 9
LTO
7
5
R