WWW.APART-AUDIO.COM
4
2. Inputs and outputs
1) Volume potmeter channel 1: 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.
2) Signal led channel 1: 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, remove the overload or let it cool down and
then power on again !
3) APC activity led channel 1: 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, without allowing any
harsh distortion.
4) Clip led channel 1: 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 !
5) Bridge led: this led lights up to indicate that the amplifier is in bridge mode.
6) Signal led channel 2: 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, remove the overload or let it cool down and
then power on again!
7) APC activity led channel 2: 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.
8) Clip led channel 2: 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 !
9) Volume potmeter channel 2: use this potmeter to preset the volume. In bridge mode, this potmeter has no
function.
Front panel layout:
1
6
7
8
9
11 16 17 18
19
10
2
3
4
5
12 13 14 15
