Some hobbyists who are building their own tube synthesizers:
The most complete list of modular-synth form factors we know of. Covers both current production and defunct manufacturers.
Magnus Danielson’s very good synthesizer hobbyist page.
One Electron–very good output transformers, plus one of the best libraries of classic
vacuum-tube circuit schematics on the web.
Electra-Print–the best tube-audio specialty transformers we know of
This site has been online since November 1998.
Last update March 2021