Evh 5150 iii channel switch with ext amp in Helix Posted Wednesday at 06:28 PM The EVH switching is "proprietary" so it does not work well with other switchers. You may be able to get it to work with an RJM product. Eddie had it designed to be seamless and as noiseless as possible. I would highly recommend using Midi to switch channels. It is very easy once you get the hang of it and works great for me. I am using the 5150 III 50 watt and the Helix Floor. I switch channels per snapshot.