Orchard Audio is running the Stereo Ultra on an amp tour. Listen to it in your system for a week then ship it to the next person on the list. You can read more on the Hoffman forums and contact Leo via the Orchard Audio website. Gan-fets are used in Orchard Audio's proprietary circuit. The Absolute Sound did a great video on using them to drive Magneplanars.
Thanks,
aldnorab