Control
elements
3
Front Panel
The front panel LED area includes the following indicators per channel:
6
Audio
input
and
output
connections
BALANCED INPUT CONNECTIONS
The XLR input connectors are electronically balanced,
and wired according to the IEC 268 standard ( pin 2=
hot ). XLR input connectors should be wired follows:
Audio input-4-channel models
Pin 1 Ground/Shield
Pin 2 Hot (+)
Pin 3 Cold (-)
When linking the same source signal to several input channels, be aware that there
is a limit to the number of channels an output source can "drive". A typical output
sourse (e.g. a DSP crossover unit) can drive up to four amplifier channels before
external line-drivers might be required to buffer the signal.
To connect an input to an unbalanced source, it is
possible to connect pins 1 and 3 in the XLR plug at the
amplifier end of the cable. However, a better method
is to connect pin 3 to the shield at the source end of the
cable, as this usually results in better hum and noise
rejection. Balanced input connections are recommended
whenever possible
Unbalanced Input connections
Speakon Output connections
Refer to the instructions in this section if your amplifier is equipped with the Speakon output connectors
Speakon outputs-4-channel models
1. LEVEL CONTROL
Calibrated detente potentiometers to alter the total gain of the power amplifier. In order to avoid
distortions in mixing consoles upstream, these controls should normally be positioned between 0 and
10. The calibrated markings show the additional attenuation directly.
2. PROTECT LED
protection under mute position.
3. CLIP/LIMIT INDICATOR
This indicator signals if the amplifier output is clipping or limiting. It has two different indication
states:
If the clip limiter is engaged, it has a short time constant, and it illuminates briefly.
If the clip limiter is not engaged, it has an increased time constant, and it illuminates for a longer period.
4. SIGNAL
LED
Green SIG Indicates output signal levels in normal operating range
5. TEMP
This LED lights up if the limiter has been activated and the power amplifier is being operated at the
clip level. If the LED flashes briefly, this is not a cause for concern. If this LED is lit permanently, the
volume should be reduced to avoid overload damages to the connected loudspeaker systems.
6. VH
F
VHF-Very High Frequency protection active ( output muted ) ( Yellow Constant )
7. CPL LED
CPL-( Orange constant with output muted ): Low impedance/Short Circuit Detection Fault
8. POWER SWITCH
Turn the unit power on or off
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2 3 4
5 6 7
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