Ecler AMPACK Series, User Manual

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4. OPERATION AND USAGE
4.1. Start up
This can be done using the power switch (20) and immediately the ON / STANDBY led (7)
will start lightning. We highly recommend the "safe power up sequence": First the sound sources,
then mixer, equalizers and active filters and, finally, power amplifiers. Powering off should be done
by following the exact reverse sequence in order to avoid any possible peaks reaching the next
device, and consequently protecting the loudspeakers, which are specially sensitive to these peaks.
4.2. Input attenuation
These are rotary trimmers located on the front panel (1, 4).
These attenuators allow the connection of different mixers, an independent volume control
and the connection of speakers not able to handle the amplifiers maximum output power, thus
avoiding the risk of damaging them with the mixers or preamps volume control.
An independent level adjustment can be done using a screwdriver or another appropriate tool.
4.3. Remote control
The AMPACK rear panel offers one terminal per amplifier to remotely control the volume,
using the built-in “VCA” circuit.
The combined usage of the rotary potentiometers located at the front panel (1, 4) and the
remote VCA (17, 18) control determines the final value of the signal’s attenuation for each input
channel. Therefore, a certain value can be fixed for the signal attenuation using the rotary so that the
remote control via VCA will not exceed this value and viceversa, that is, the two controls are
connected in series.
4.4. Connection of the VCA control
As already mentioned in the introduction of this manual, the signal attenuation level for each
of the input channels can be set using the following methods:
a) Using a remote potentiometer with nominal resistance between 10k
Ω
and 50k
Ω
.
b) Using a device that generates a control voltage from 0 to 10V DC.
c) Using remote relays/dry contacts.