Cool. I'm old enough that I've actually worked with tubes (final amps for 1970s Ham Radios needed too much power to sensibly use the solid-state transistors of

Cool. I'm old enough that I've actually worked with tubes (final amps for 1970s Ham Radios needed too much power to sensibly use the solid-state transistors of the day. Also Fender guitar amps were just turning solid-state in the late 70s/early 80s, so used tube amps were cheaper.) I would not have guessed that the first ones happened in 1889; Anyone have a favorite link for tube history?