The Lyr+ switches seamlessly to its internal solid-state gain stage, based on exotic depletion-mode MOSFETs if you don't plan to use tube mode. You can always switch to tubes such as 6SN7-type, and Lyr+ switches over to 100% tube voltage gain with the MOSFETs out of the picture. The Schiit Lyr+ is the answer to the magic of Fusion Architecture