178.738UK User Manual
Wiring for balanced mic and unbalanced line inputs are shown below.
Operation
To check an input, ensure that Pan and Low / High EQ controls (2, 4, 5) are set to the vertical
(12 o’clock) position and the Level, FX and Gain controls (1, 3, 6) are turned fully down.
Turn the Master volume controls (21) down and set all Graphic EQ sliders (20) to halfway position.
Some microphones and DI boxes require phantom power to operate (check manufacturer’s spec.)
A Phantom power switch (25) pr48V to all XLR inputs with an indicator to show when active.
Switch the mains power on (28) and check the microphone or line level input whilst increasing the
Gain control (6) until the red Peak LED (7) lights when the loudest sound is produced at the input.
Back the Gain down control down until the Peak LED lights only momentarily on the loudest sounds.
The channel gain is now set to match the input source.
Turn up the Master volume controls up part way and gradually increase the Channel output level (1)
for the microphone or line input source whilst checking the output through the connected speakers.
Alternatively, a USB pen drive with compressed audio tracks stored can be connected to the USB
Audio Player (10) for checking playback. More details are shown in the “USB player” section below.
Once the sound has been checked through the speakers, increase the Master volume to the required
level, ensuring that the LED level meter (19) doesn’t continually reach into the red (+7dB).
The red +7dB level meter LED should only ever light briefly on the loudest peaks of the sound (e.g.
bass drum beat) and if it lights for anything longer than momentarily, the Channel or Master levels
must be reduced until it stops lighting.
Adjust the channel output level controls (1) to balance the mix and if required, adjust the tone of any
channel by boosting or cutting the Low and High controls (4, 5) – the vertical position is neutral.
Further tone adjustment for the overall mix is available via the master Graphic Equalizer (20).
This section is home to 2 sets of 7 sliders which range from 63Hz to 16kHz centre frequencies.
Halfway up the slider is neutral, top position is 12dB boost and bottom is 12dB cut of that frequency.
