Outputs; Further Considerations; Ground Loops; Audio Connections - Ecler HAK380 Bedienungsanleitung

4.11. Outputs

Headphones: to obtain the maximum efficiency from their operation, the headphones must have
high impedance (200-600Ω). They have to be connected to the PHONES output (60), which is provided
with normalized stereo TRS connectors, one with 6,35 mm and another with 3,5 mm. The sleeve will be
the ground, the ring the right channel and the top the left channel.
The HAK380 has two main outputs, OUT1 and OUT2.
OUT 1 is provided with balanced XLR3 (17, 18) and 6,35 TRS (8, 7) connectors with 0dB at
600Ω and one RCA connector (19) with 0dB at 1kΩ. With the LEVEL switch (6) located at the back
panel of the unit, the output level can be modified from 0dB to +6dB.
OUT 2 (20): RCA, 0dB at 1kΩ, can be configured internally to +6dB using welding bridges (see
fig. 2)
Both outputs have rotary potentiometers (31, 32), which allow to perform the level adjustment.
The switch L+R (5), located at the back panel, converts both outputs into mono outputs.
The HAK380 also has two advisory leds (29, 30), one for each output, that lighten up when the
existing level exceeds the nominal level (1V). This red LED should be blinking during the performance
and never remain permanently lightened up.
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 HAK380 mixer has a REC (16) output of 0dBV nominal on 10kΩ 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.
10