Connect a pair of XLR cables from the right and left outputs on your audio source device to the corresponding right and left inputs on the back of the D2040.
Connect a set of XLR cables from the right and left output jacks for Channel 1 on the back of the D2040 to the corresponding right and left inputs on either a set of speakers or an audio device.
Repeat Step 2 for Channels 2 - 4.
Push the power button on the D2040 to turn the device on.
Rotate the "L" and "R" knobs under each channel (labeled 1 through 4) clockwise to increase the volume for that channel or counterclockwise to decrease the volume.
Press the "Mute" button over each "L" and "R" knob for each channel to mute the volume. Press it again to unmute it.