viola posted a topic in HelixHi, I' ve tried several times to switch in "dinamic range" my Marshall Vintage Modern by "Ext Amp" on Helix. No combination is able to switch it. I use 4CM. I' ve heard that' s impossible to switching, because VM use a relay and Helix "Ext Amp" not has relay. Is it correct ? If yes, any suggestions to solve this problem? This amp hasn't MIDI controls… Anyway, "Ext Amp" feature it's not a "great work" ….many modern amps use footswitch relay and all of them are unswitchable by Helix.