Ecler HMA120, User Manual

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7. POWERING AND OPERATING
7.1. Switching on the unit
This is done directly by using the ON/OFF switch (26) on the back panel, lighting up the front ON
LED indicator (1). In a complete audio installation, it is important to start up the equipment in the following
sequence: sound sources, mixer, equalizers, active filters and finally power amplifiers. To turn them off
the sequence should follow an inverse pattern.
7.2. Gain adjustments, levels and indicators
Adjust the input gain level for each signal using its ADJ control on the rear panel (34, 36: MIC1 and
MIC2/LINE inputs).
Then, adjust the relative mix volume of the input channels using their respective level controls on
the front panel (18, 21, 24). The SIGNAL indicator (2) begins to light up when signals are sufficiently
present to be audible, lighting up with greater intensity when the level increases. The CLIP indicator (3) will
begin to light up when the mix level is so high that it comes close to the clipping threshold of the unit.
It is normal that when operating at high output power, the CLIP indicators light up in rhythm with
the low frequencies, which carry the most energy. Make sure that these indicators do not remain
permanently lit.
Additionally, you can activate the Noise Gate and/or Talkover functions for the MIC1 and
MIC2/LINE inputs, via the switches on the left side of the unit. Refer to section 4.1 MIC1, MIC2/LINE
Inputs for more details.
7.3. Equalisation
The tone controls for the different inputs (19, 20, 22, 23) provide a gain/attenuation of ±10dB for
each of the following bands:

BASS: 100Hz ± 10dB

TREBLE: 6kHz ± 10dB
Given the philosophy of use of the product, it has a tone control system that requires a screwdriver
adjustment, thus preventing operating mistakes during its daily use.
7.4. Auto Stand-by Function
You can enable the automatic switching to low power mode using the dedicated switch located on
the left side of the unit. When activated, the HMA120 enters the low power mode after detecting the
absence of audio signals at the inputs for a period of 2 minutes or more, returning back to normal operating
mode upon detecting a valid input signal.
7.5. Ground loops, background noise
You must always avoid interconnected grounds between signal sources. It means grounds must
never arrive by two or more different ways, since this could produce "hum" ("ground loop") that would
even interfere with the sound reproduction quality.
Cable shielding, when connected to the chassis, must never be interconnected, so as to avoid
ground loops.