178.190UK User Manual
Operation
Once all connections have been made as described above, turn down the Master Volume control (21) and
Monitor Output Volume control (19).
Switch the power on to the powered mixer module and the power LED (20) will light.
To check inputs 1-4, ensure that the Mic/Line switch (3) is set to the correct type of input source.
Set the Treble and Bass controls (4, 5) to the vertical (12 o’clock) position and ensure that the Effect and
Volume controls (6, 7) are turned fully down.
Turn the Master Volume control (21) up part way and gradually increase the channel Volume (7) checking
for output from the speakers whilst speaking into the microphone, playing the instrument or playback
device. A similar test can be made using any of the stereo line inputs (8, 9, 11)
Alternatively, a USB pen drive or SD card with compressed audio tracks stored can be connected to the
USB/SD player for checking playback and sound-checking the system.
More details are shown in the “Internal USB/SD player & Bluetooth receiver” section.
Once the sound has been checked through the speakers, increase the Master Volume to the required level,
ensuring that the LED level meter (20) doesn’t continually reach into the red (+6dB)
The red +6dB 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 should be
reduced until it lights only briefly (above this level, the amplifier will self-limit to avoid damage)
Adjust the channel Volume controls (7) to balance the mix and if required, adjust the tone of any channel
by boosting or cutting the Treble and Bass controls (4, 5) – the vertical position is neutral.
For microphones, the Effect control (6) governs the level of signal sent to the internal delay (echo) effect.
This effect has controls for Repeat (14) and Delay (15)
Turning up the Repeat control increases the number of repeats returned by the delay effect.
Turning up the Delay control increases the speed (reduces time) between the repeats.
If monitors or further active speakers are connected via the Monitor Outputs (16), these are governed by
the Monitor Output Volume control (19), which will need to be turned up to the required level.
The L+R RCA output and headphones output are not affected by the Monitor Output Volume control.
When the unit is not in use, turn down the Master Volume and Monitor Output Volume controls before
powering down in order to avoid damage to the DUET300 and other connected equipment.
