GR2. Reset Print to PDF 26 March 2026 12:46 Updated Hold down the four grey source-select switches on the front panel of the unit whilst powering up. Related articles GR4 User Guide General. Spare Parts - identification and ordering MixWizard4. WZ4 USB Audio Option (W4-USB) Phase Coherent Mixes (dLive, Avantis) Browser based MixRack Firmware Update