There are a couple of ways to do what you are asking. Probably the easiest is to use two M/E Outputs that you're not using and 2 keyers that you're not using. For example... Lets say you're using Auxes 15 & 16 to feed the Vizrt. If you are not using ME1OP2 and ME1OP3 for anything, select the first on Aux 15 and the later on Aux 16. If those M/E Outputs are not mapped to any buttons on the Aux Panel, you can always dial up the M/E Outputs on the GUI in the Aux Setup menu - then lock them. Let's also assume that M/E 1 is used mainly for chroma keys or other simple stuff and you rarely use Keyers 2 and 3. In this case, you would go to ME Output setup in the ENG Config menu and set ME1OP2 to Black as the Background with Key 2 ON and Keys 1, 3, 4 OFF. Then set ME1OP3 to Black as the Background with Key 3 ON and Keys 1, 2, 4 OFF. Now you would use the Key 2 Bus on M/E 1 to feed converted sources to Aux 15 and the Key 3 Bus on M/E 1 to feed converted sources to Aux 16. Of course you can use any combination of Auxes, Keyers, and M/E Outputs to accomplish this. You can also go a step further and use Bus Linking to use one of the 64 internal Aux Buses to control the switching on the Key Buses. You will find Bus Linking in the Panel Config menu. The advantage of this is it would allow you to use a remote Aux Panel to essentially control switching on the unused Key Buses of the 4 M/E control panel. A new OPTION available with 3.3 software and newer is the ability to change an unused M/E bank into 8 Aux Buses with FormatFusion. Whether or not you can afford to lose an M/E to gain 8 Aux Buses with conversion is for you to decide. Cheers, -= Ken =-