Now, turn up the Aux Send knob on the channel you want to process. If there is an Aux Send Master for that Aux turn it up to unity. Turn up the input level on your processor for a line level signal. Turn up the output on your processor to unity.Turn the Aux Return knob on your mixer up to the desired level of effects you want to hear in the Main Mix.(This process is also explained in detail on pages 12-13 of your owner’s manual.).ow, turn up the Aux Send knob on the channel you want to process. If there is an Aux Send Master for that Aux turn it up to unity. Turn up the input level on your processor for a line level signal. Turn up the output on your processor to unity.