Electronic circuit schematics, manuals, books, datasheets. Since Y2K.
19 Apr 2025 -- New format underway. Archives grown substantially. Up soon.
For 23 years schems.com ran open, unmetered. Millions of downloads, inumerable terabytes later: Yahoo and google proved among worst of pointlessly punishing grabbers now necessitating download tokens or login.
Data Sheets
Electron valve / vacuum-tube datasheets.
Schematics
Audio equipment galore including Schematic-Heaven mirror, pedal effects, etc.