Turn all knobs and faders to zero. Turn the "Gain," "Aux" and "Fader" control knobs to the left, and center the "EQ" and "Pan" controls. Push all buttons so that they are in the "Out" position.
Turn on the mixer board. This step is not necessary for unpowered mixers.
Plug in the audio source via the "Audio In" inputs. There are two common types of audio inputs: XLR (or preamp) plug and 1/4-inch plug. Microphones plug in via the XLR jack; guitars and other instruments use the 1/4-inch jack input.
Listen to the mix using headphones or speakers (also known as monitors) by plugging them into the "Audio Output." Listen to an individual channel by selecting PFL (pre-fader listen) or to all channels at once by selecting AFL (after-fader listen).
Adjust the channel's "Volume," "Gain" and "Channel Fader" settings to the desired listening level.
Push the "Main Mix" button to the "On" position. Adjust the Main Mix knob and the Fader to bring the mix to the level you want.
Send the Main Mix to the monitors or another output. The "Main to Mon" control sends the mix to the main monitors, which are usually the audience's speakers; the "Control Room" control sends the mix to the audio engineer's headphones.
Adjust the EQ and Pan controls to create the sound effect you want.