The Zapco Z8-R is an optional Dash Remote available for those who will use the auxiliary inputs of the DSP-Z8. The Z8-R allows auxiliary functions to be accessed without the need to have a PC connected to the system while on the road. (Safety First Please). First, the Z8-R privides a switching system (MODE button) so the user can toggle between the Main-In, the analog RCA input (AUX A) and the Digital SPDIF input (Aux D). Three LED indicators let the user know which input is currently active. Since almost all digital inputs will be full gain out from the source, using the digital input will require a remote gain control. A pair of Up/Down buttons allow you to control overall volume in 1/2 dB steps. Again: Digital inputs are usually full gain, so you must take care to avoid surprises and dangerous distractions of abrupt volume changes. We highly recomend that if you are using the Aux-D input in your system, you should set your head unit to maximum unclipped output (usually about 3/4 volume), and use the Z8-R as your main volume control. This way switching from Main input to Aux-D input will not cause severe volume changes. The Z8-R also provides memory switching. The DSP-Z8 lets you set up several global tuning systems for different types of music or for different listening needs (Say for sitting and listening to the music or when you need background music without bass for when the kids are in the car). With the Z8-R you can change which memory setting is active at anytime, without the PC connected. Four LED indicators let you see at a glance which memory setting is active. The Z8-R has a USB connector on the front panel. If you have the Z8-R mountedin the dash or in the glove box, you can plug your PC into the system for tuning right from the front seat. The Z8-R also has a "reset" button. This button will only be used only if the system should need to be updated with future program changes.