Connect your audio sources to the inputs of the UB1202FX. Use the headphones or speakers to monitor effective sound levels. Adjust the levels so they are comfortable and do not distort the mixer preamps, indicated by the "Clip" light on the mono channels.
Add a signal to the effects circuit by rotating the "FX" control on any channel to which you wish to add an effect. These signals will be mixed prior to the input of the effects unit. Using different amounts of effect on different signals can be effective, such as reverb, where more effect gives the illusion of an instrument or vocal being farther away.
Turn the "FX to Main" control clockwise until the effect is as loud as you want. To monitor only the effect signal without the main audio, press the "FX to CTRL" button. This procedure will route the effected sound only to your headphones or monitors. This method is useful for setting the relative level of each signal sent to the effects unit.
Choose a different effect by rotating the "Program" control either clockwise or counterclockwise. The LED display will change, indicating the program. Press the "Program" knob to select the displayed number. If the LED display is blinking, the program is not yet selected.