Outputs; Further Considerations; Ground Loops; Audio Connections - Ecler HAK300 Notice D'emploi

4.9 Outputs

Headphones: in order to obtain a high performance, these should be of the high
impedance type (200-600). Plug them to the HEADPHONES output (26), in the front panel, by
means of a standard stereo jack. Sleeve is Ground, Ring is Right Channel and Tip is Left Channel.
The HAK300 has two main outputs OUT1 (8) RCA, 0dB at 1k, and OUT2 (7) RCA, 0dB
at 1k with their own volume control by using a rotary knob to adjust the output signal. Jumpers (Fig
2) can internally adjust main outputs to +6dBV (2V).
CAUTION: Changes on the Output Level have to be performed by a qualified technician.
ATTENTION: You must be careful when setting up the general output level of the
mixer. The "clip" display of the connected power amplifiers must never remain permanently lightened
up, but do it occasionally by following the rhythm of the bass signals that are being played.
The HAK300 mixer has a REC (9) output of 0dBV nominal at 10k load.

5. FURTHER CONSIDERATIONS

5.1. Ground loops

Ensure at all times that no signal sources reaching the mixing desk and no devices
connected to its output have their earths interconnected; that is, earth should never reach them via
two or more different paths, as this could lead to humming which could even interfere with sound
reproduction quality. In order to avoid earth loops, ensure that the shielding of cables, if connected to
the chassis, are never connected with each other.

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 held cheap, 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 HAK 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.
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