While working on his undergrad at Michigan State, [Gregory] thought it would be a great idea to build an all-tube home theater system. He calls his seven-foot tall rack of amplifiers ...

The GA-10 is an audiophile-grade headphone amplifier that features the SEPP (single-ended push-pull) circuit with eight vacuum tubes, a linear transformer, and direct tube output. The vacuum tubes ...

which is surprising when you understand that it’s not an audio tube at all. Instead it’s a small-signal VHF amplifier, a rough equivalent of the European EF95, and would be much more at home ...