I hope not but you may be right. I put large series resistors in place that are bypassed by the relays and fly back diodes around the coils so hopefully it’s minimal. I’ve done other switching schemes like that on different amps that weren’t audibleWhen I have built the mkiv clone, my second prototype was using relays. You might experience some popping noise when switching chanels, unless you mute the amp like the newer models during the switching.