Yes it does bypass the gain stage. I think ARC has the function since LS-2. I had the LS-1 and it did not have that function. I then went to LS-3. But can't remember if it has it or not. My 3rd pre was the LS-2b Mk II, and it definitely has that function as I had my system set up where I was using that mode to run my HT set up. My next and current pre is the LS-25. But I decided to separate my audio and HT systems completely, thinking that burning 4 NOS tubes while watching movies (and not even getting any benefit out of them) would be a waste.