5
10) Power switch and power led: flip the switch to power on the amplifier. The blue led will light up to indicate
that mains power is present.
11) Volume potmeter channel 3: use this potmeter to preset the volume. In case the amplifier has been switched
to bridge mode, this potmeter sets the level for bridge operation.
12) Signal led channel 3: this led lights up green when a sufficiently strong signal is present on the first channel,
after passing the input level control. At startup, the led will light up red during a few seconds, this is perfectly
normal. When it lights up red during use, the power transformer or power amplifier is overheated or in
protect mode and is shut down. Turn off the power.
The amplifier will not turn on automatically after
most error conditions. In some cases, the user MUST turn off power and remove the overload and
then power on again !
13) APC activity led channel 3: this led lights up when the APC circuitry is active. The APC circuitry reduces the
gain at the inputs to guarantee the full dynamic range of the power amplifier circuits.
14) Clip led channel 3: this led lights up whenever the amplifier clips. This is a warning sign: you are pushing
things a little too far or you are overloading the amp. Reduce the input level by a few dB so that this led
never lights up anymore ! Don’t ignore this !
15) Bridge led: this led lights up to indicate that the amplifier is in bridge mode.
16) Signal led channel 4: this led lights up green when a sufficiently strong signal is present on the left channel,
after passing the input level control. At startup, the led will light up red during a few seconds, this is perfectly
normal. When it lights up red during use, the power transformer or power amplifier is overheated or in
protect mode and is shut down. Turn off the power.
The amplifier will not turn on automatically after
most error conditions. In some cases, the user MUST turn off power and remove the overload and
then power on again !
17) APC activity led channel 4: this led lights up when the APC circuitry is active. The APC circuitry reduces the
gain at the inputs to guarantee the full dynamic range of the power amplifier circuits.
18) Clip led channel 4: this led lights up whenever the amplifier clips. This is a warning sign: you are pushing
things a little too far or you are overloading the amp. Reduce the input level by a few dB so that this led
never lights up anymore ! Don’t ignore this !
19) Volume potmeter channel 4: use this potmeter to preset the volume. In bridge mode, this potmeter has no
function.
Note : signal leds 2, 6 , 12 and 16 have multiple functions: during the first few seconds of startup they
light up red, this is perfectly normal. When a strong audio signal is present on the amplifier circuit,
the leds light up green. When an error occurs during operation, they will turn red to indicate an error
condition and the speaker relays will switch off automatically. Possible causes can be : amplifier error
or DC on the output, amplifier overheat or transformer* overheat. In such cases, remove the error
condition or overload and wait until the unit has cooled down before powering on again.
*In case the transformer is overheated, it may take a long time before the amplifier has cooled down sufficiently.
In such cases, you may have overloaded the amplifier too much. Power off the amplifier immediately, correct the
error and wait until the amplifier has cooled down.
