Ground Loops, Background Noise; Cleaning - Ecler SAM312 Notice D'utilisation

6.4. Ground loops, background noise

You should always make sure that the signal sources coming to the unit, as well as all devices
connected to its outputs, do not have their grounds interconnected, that is; ground must never come from
two different devices. Should this ever happen, noises could occur and seriously interfere the sound quality.
Cable shielding, when connected to the chassis, must never be interconnected, so as to avoid
ground loops.
The SAM312 mixer has been designed for the lowest possible background noise. Independently
from the electronic design itself, background noise level will directly depend on the right installation and use
of the mixing unit.
I. e.: setting a channel VOL to "2" and the output to "10" is not the same as the other way round. In
the first case, the signal coming to the mixing amplifier - which has got its own noise - is low, and so is the
signal-to-noise ratio (low signal). When the output amplifier boosts the whole signal we will get a very high
background noise. In the second case - with the channel fader at maximum - the mixing level is high, and
so is the signal-to-noise ratio. When the signal reaches the VOL OUTPUT and is boosted, it will keep a
much better signal-to-noise ratio than in the preceding case.

6.5. Cleaning

The front panel should not be cleaned with dissolvent or abrasive substances because silk-
printing could be damaged. To clean it, use a soft cloth slightly wet with water and neutral liquid soap;
dry it with a clean cloth. Be careful that water never gets into the unit through the holes of the front panel.
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