Back side of circlotron output stage power amp. Right side PCB contains driver stages, direct coupled parallel ECC85 driven by AC coupled plate loaded 6N3EP triode. Custom duble C core output transformer (DIY section),designed for 6c33c triodes. 9 seperate (left side PCBs) mosfet regulated power supplies (2 floating). 125wpc with 10dB NFB, class A operation to 40 Wrms. Nice and accurate sound with plent of triode power.