Output Sensitivity Adjustment; Considerations; Ground Loops; Audio Connections - Ecler MAC70i Notice D'emploi

4.7.2. Output sensitivity adjustments
Same as with the input sensitivities, the output levels are also internally and independently
adjustable. The following table shows the jummper arrangements for the desired levels:
CHANNEL R
OUTPUT 1
J102
-10dBV OFF
0dBV ON
+4dBV OFF
+6dBV ON
ATTENTION: The modification of the output gain must be carried out by a qualified
technician.

5. CONSIDERATIONS

5.1. Ground loops

You should always try that all sources which reach the mixer, as well as all devices
connected to its output, do not have their grounds interconnected between them, that is, that they
never get the ground signal through two or more different ways. Sould this ever happen, hum and
noise could appear and interfere the sound quality.
The cable shielding, when connected to the chassis, must never be interconnected
between them. This way ground loops will be avoided.

5.2. Audio connections

As a general rule of thumb, make the signal connections as short as possible and use the
best connectors and cable available. Cables and connectors are frequently undervaluated, forgetting
that a bad connection can result in a poor sound quality.

5.3. Background noise

The use of active circuitry can yield, depending on the configuration, to a significant noise
level. The MAC70i mixer has been designed for the minimum possible noise. Anyway, the noise
level will always depend on the correct use and installation of the mixer.
It is not the same setting up the "FADER" at "2" and the "MASTER" at "10" that the other
way round; "FADER" at "10" and "MASTER" at "2". In the first case you get a poor signal-to-noise
ratio that will be fully amplified by the master while on the second we have a good signal-to-noise
ratio only amplified by 2. As a result, the background noise is greater in the first case than in the
second one.
CHANNEL L CHANNEL R
OUTPUT 1 OUTPUT 2
J103 J104 J105 J106
OFF OFF OFF OFF
OFF ON OFF ON
ON OFF ON OFF
ON ON ON ON
CHANNEL L
OUTPUT 2
J107 J108 J109
OFF OFF OFF
OFF ON OFF
ON OFF ON
ON ON ON
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