InfoComm 2019: Roland Debuts 4-Channel VR-50HD MK II Multi-Format AV Mixer with Video Follow AudioJune 19, 2019 | Home / June 19, 2019 rave-video / InfoComm 2019: Roland Debuts 4-Channel VR-50HD MK II Multi-Format AV Mixer with Video Follow Audio InfoComm 2019: Roland Debuts 4-Channel VR-50HD MK II Multi-Format AV Mixer with Video Follow Audio