The QX series of Xenyx mixers contain an Ultra-high quality KLARK TEKNIK FX processor with LCD display, dual-parameters, Tap function and storable user parameters. Please note the following guide only applies directly to the QX1204USB, QX1622USB and QX2222USB To begin here is a list of the general effects to be found on the QX1204USB, QX1622USB and QX2222USB: When using the FX Processor only one effect can be selected at a time multiple channels can be sent to said effect simultaneously. A more detailed list of the effects can be found on pages 14 and 15 of the QX series user manual at the following link. Including details of the of editable parameters. Below is a diagram is the controls on the QX1622USB which set up the FX with an explanation of their use. Channel FX Send Each input channel strip on the QX1622USB has a FX Send Pot used for controlling the amount of signal from said channel is sent to the effect processor. Using these controls it is possible to send as many channels as you like to the same effect. For example the signal from you snare microphone on input 2 and your vocal on input 4 can be sent to the same reverb affect with individual control over how much of each signal is sent. FX Processor The PROGRAM/VALUE knob can be turned to scroll through effects on the display screen and pressed to select and effect. Once an effect has been selected you can press any of the parameter buttons to edit the effect (pressing PARAMETER 1/2 twice to edit parameter 2) the value is changed by turning the PROGRAM/VALUE knob. After 4 seconds of inactivity, the mixer exits Edit mode and your parameter is saved. The PARAMETER 3 [TAP] button can be used as a tap tempo control for time based effects such as echo or delay. Next to the effect name the VU meter displays the amount of signal entering the effects processor, if this overloads then you need to turn down the Aux FX Send (see FX Routing section). Below is an example of the edit parameters of the CHURCH reverb effect. FX Routing In the AUX SENDS section you can use the FX Solo button to listen to only the wet signal from the FX unit and use the pot to change the overall signal of all Channel FX Sends to the FX module as a group. You can use the button in the STEREO AUX RETURNS section to route the FX to either the MAIN MIX outputs (button up) or the SUB 1-2 outputs (button down). Here the pot controls the level of FX output to the Main Mix or Sub outputs.