"Organ donors"... or: sources for tube project parts...
Vacuum tubes and parts tend to be rather expensive these days. But there's a good source for parts, and it's often free: old tube organs.
I picked up a working 1960 Wurlitzer a couple days ago. It's got:
-- full complement of tubes (the mother lode!), including
9 (nine!) 12AX7 preamp tubes.
2 6L6-GC power tubes
1 5U4-GB rectifier
(there were other tubes: (28!) 12fq8's but they're not so useful for audio...)
-- Huge power transformer
-- Large (20-25 watt) output tranformer
-- two 16 ohm speakers
-- lots of carbon-comp resistors, sockets and other reusables.
Total cost--just gas, and a sore back.
Even the non-tube organs are a good source of speakers, reverb tanks, pedals, etc. The tank, bass pedals and the volume pedal were from a solid-state Conn organ left on the curb...
The bass pedals could be made into a MIDI project, and the volume pedal would be a nice start of a wah, or left as-is. Yeah, they are grungy, but that's easy to fix....