This listing is two pieces of bare PCBs of "power follower" 2019 by the designer, audio expert Mr. Andrea Ciuffoli. This is the newest version 2019 and an authorized PCB version by the designer.
This listing DOES NOT include the tube driver board. JUST TWO PIECES of power amp boards.
For the project details, please refer to http://www.audiodesignguide.com/PowerFollower/index1.html.