So, I was sitting here on this rainy Sunday morning going through some amplifier designs and looking through my stash of tubes and various amplifier building supplies. While standing there looking at the shelves of vacuum tubes, transformers, and various piece-parts, my eyes drifted up to an amplifier sitting on the top shelf. It was my 6AS5 µ-power UL amplifier documented here. But why was the little amp sitting on a shelf collecting dust? Then I remembered.