Dynacord PM2600 - Manual (Page 15)

15
CHANNEL A, B
Level Controls For The Channels A, B
These level controls are used to adjust the power amplifier’s input sensitivity. They should be positioned
between their “0“ and -6 dB mark. Too low settings for the input sensitivity can result in distortion in the
output stages of the connected mixing console which then off course would also effect the processor sta-
ge of the power amplifier.
Input Signal Indicators For The LO/HI Channels A, B
The input signal indicators are located pre-input level controls, indicating the audio signals outputted from
the connected mixing console. The LEDs also light when the power amplifier’s level controls are set to
their minimum position. This ensures that, when setting up the sound system, the audio signal can be op-
tically monitored at the power amplifier, without the need to reproduce the sound through the loudspeaker
systems.
Output Signal Indicators For The LO/HI Channels A, B
These LEDs indicate the output voltage of the power amplifiers. The LO-indicators represent the output
voltage of the bass power amplifiers while the HI-indicators represent the output voltage of the MID-HI
power amplifiers. The LEDs are directly fed from the output connectors which additionally provides optical
information of short-circuits in loudspeaker lines. Whenever a faulty condition like a short-circuit occurs
and even though the audio signal is reproduced, the corresponding indicator does not light at all or is dim-
med.
LIMIT
The limit indicators light whenever the internal limiter is activated and the power amplifier is operated at
its limits. Short-term or frequent blinking does not represent any problem. If the LEDs are continuously
lit, reducing the output level is recommended to prevent the connected loudspeaker systems from being
damaged by overload or clipping.
Thermal Brain Circuit (TBC)
The internal power amplifiers are capable of producing output peaks that by far exceed the nominal out-
put power capacity as stated in the specifications. To protect the connected loudspeaker systems from
being damaged, the TBC reduces the output power: either after a short period of time when the regular
output level is continuously exceeded, it is reduced to its nominal value or, depending on the overdrive
condition, even a bit lower. A lit LED indicates that the sound system is operated exceeding its output ca-
pacity which means, that the connected loudspeaker systems operate in a thermally critical range. In this
case reducing the output level of the mixing console is strongly recommended.
PROTECT
This indicator lights during operation when one of the protection circuits - thermal overload, short-circuit or
HF at the outputs - has been activated. Whatever caused the defect - for instance a short-circuit in one of
the loudspeaker lines - has to be eliminated. In case of thermal overload, you have to wait some time until
the power amplifier automatically re-enters operation mode.
POWER CN
IndicatorWhen the power amplifier is in operation mode the LED lights. If the LED does not light after
switching the power on, presumably the mains cord is not correctly plugged in or one of the mains fuses
is blown.
POWER Switch
This push-button switch turns the power on. The loudspeaker outputs are switched delayed via relay. This
prevents any power-on noise from being heard. An initial inrush current limiter circuit protects the entire
system from being damaged during the power-on operation.
FRONT PANEL