Changing channels on my Mesa Studio pre with a g major

[tonefreak25]

Ok, I know this, or something like it has been done/covered. But do I need a y cable or can I use a stereo tipped cable or something different here? Greatly appreciate any help on this. As I would love to be able to set up the g major to switch back and forth between my 2 channels on the studio pre. Any helpful advice would be appreciated. Thanks.