CONTRACTOR PRECISION SERIES
14 Owner‘s Manual
3 Operation
3.1 Volume Control
In DUAL and PARALLEL mode, the level controls LEVEL on the power amp’s rear panel are used to control
the amplification of the corresponding channel. Turning the control to the right increases and turning it to the
left decreases the volume. In BRIDGED mode operation, the output volume for a pair of outputs is only
controlled by the level control of the channel with odd number (1, 3, 5 or 7), the setting of the channel with
even number (2, 4, 6 or 8) is ignored.
3.2 Indications
PROTECT
The PROTECT LED lights indicating that one of the internal protection circuits against thermal overload,
short-circuit, Back-EMF, HF-occurrence at the output, etc., has been activated. In that case, the connected
load is separated from the power amps to prevent the connected loudspeaker systems and the power
amplifiers as well from being damaged. Whatever caused the fault – e.g. a short-circuited speaker cable –
needs to be remedied. In case of thermal overload you have to wait until the power amplifier automatically
regains normal operation.
MUTE
The MUTE LED lights red whenever the power amp’s output signal is being muted, which happens when
manually muting the output signal via IRIS-Net.
-30dB...LIMIT
Level indication is realized via vertical LED chains on the power amp’s front panel that individually indicate
the actual levels of each channel at -30dB, -10dB and -3dB below full modulation. The LIMIT LED lights as
soon as the integrated dynamic audio limiter is activated and the power amplifier is driven at the clipping
limit or generally at its maximum capacity. Short-term blinking is not a problem, because the internal limiter
controls input levels of up to +21 dBu down to a THD of approximately 1%. If, on the other hand, the LIMIT
LED light constantly, reducing the volume is recommended to prevent the loudspeaker systems connected
from being damaged by probable overload.
POWER
The POWER LED lights green when the power amplifier is on. If the POWER LED does not light, despite
the fact that the amplifier has been switched on, this indicates that the power amp is not connected to the
mains or the primary fuse has blown.
STANDBY
The STANDBY LED lights yellow when the power amp is in standby mode. Standby mode reduces the
amp’s power consumption to an absolute minimum. Activating the standby mode is possible via IRISNet or
the POWER REMOTE port at the amp‘s rear panel.
IRIS-Net
The IRIS-Net-LED lights blue if an IRIS-Net compatible remote control module has been installed in the
power amp’s extension slot and successful data communication has been established. The IRIS-Net LED
blink slowly whenever the “Find” function in IRIS-Net is being used to locate a power amplifier in the rack.
3.3 Standby Mode (POWER REMOTE)
POWER REMOTE provides a simple way to remotely power-on/off the power amplifier. The
POWER REMOTE function is only useful for appliances not employing a Remote Control
Modul. Controlling appliances with Remote Control Module installed per REMOTE
CONTROL is practically pointless. Leaving the pins of POWER REMOTE socket open the
appliance power is switched on. When connecting the pins the applicance enters standby
mode.