Ecler AMPACK Series User Manual

Contents

74. OPERATION AND USAGE4.1. Start upThis 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 doneby following the exact reverse sequence in order to avoid any possible peaks reaching the nextdevice, and consequently protecting the loudspeakers, which are specially sensitive to these peaks.4.2. Input attenuationThese are rotary trimmers located on the front panel (1, 4).These attenuators allow the connection of different mixers, an independent volume controland the connection of speakers not able to handle the amplifiers maximum output power, thusavoiding 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 controlThe 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 theremote VCA (17, 18) control determines the final value of the signal’s attenuation for each inputchannel. Therefore, a certain value can be fixed for the signal attenuation using the rotary so that theremote control via VCA will not exceed this value and viceversa, that is, the two controls areconnected in series.4.4. Connection of the VCA controlAs already mentioned in the introduction of this manual, the signal attenuation level for eachof the input channels can be set using the following methods:a) Using a remote potentiometer with nominal resistance between 10kΩ and 50kΩ.b) Using a device that generates a control voltage from 0 to 10V DC.c) Using remote relays/dry contacts.