Each of the four channels may be individually operated in GATE or EXPander mode. Balanced or unbalanced signals may be applied to the XLR style input connectors. To further expand the 564E's functional possibilities, a control loop (send and return) is included for devices like delay lines and graphic equalizers (for enhancement of frequency sensitive operation). This allows special effects and manipulation of problem audio sources. Wide range front panel control allows extensive signal manipulation to solve problems found in both studio and live environments. With all controls being fully variable, the level of performance you are able to extract from the 564E depends entirely on your understanding of these controls. For this reason, the following pages include a tutorial section to aid in understanding the various functions available from the 564E.