The MiG-25 used nuvistors[1] for the avionics, which are quite small compared to your average stereo amplifier tubes. Sure it requires high voltage, though "onl

The MiG-25 used nuvistors[1] for the avionics, which are quite small compared to your average stereo amplifier tubes. Sure it requires high voltage, though "only" around 100V[2]. But yeah, still not great for making robots. [1]: https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor [2]: https://archive.org/details/manualsbase-id-455546/page/4/mode/2up https://archive.org/details/manualsbase-id-455546/page/4/mod...