| AHF Art Audio | Transformers, Tubes, Schematics |
| Antique Radio Repair | Tube Radios & Related Vintage Items, Schematics |
| Audio Experience | Tube Amplfiers, Schematics, Links |
| Audio Oasis.com | Retailer, Tubes |
| AudioFanatic | Links, Schematics, DIY Tube Audio Site |
| Audiofans.net | Forum, Links, Information |
| Audiophilia | Schematics |
| Consumer Audio Information | Schematics |
| Cool Schematics | Schematics |
| Dr. Tube | Schematics, Link List, Tube Database |
| Dredge | Schematics, Manuals |
| Duncan's Amp Pages | Tube Guitar Amplifiers, Tube Data, Information |
| Elettronica ED ST62 | Schematics, Ham Radio |
| Evolve Power Amplifiers | DIY Tube Amplifiers, Schematics, Forums |
| Fi Primer | DIY Tube Amplifiers, Schematics |
| Fourier Components OTL Amplifiers | OTL Tube Amplifiers |
| Funkamt Flensburg | Schematics, Tube Comparison List, Links, Tube Radios & Related Vintage Items |
| Gary Pimm | DIY Tube Amplifiers, Schematics |
| Gary's Audio Pages | DIY Tube Amplifiers, Schematics |
| GSTubes, radio tubes, valves | Tubes, Vacuum Tube Sockets, Schematics |
| Heathkit Schematic Library | Schematics |
| Infotronix | Manuals, Schematics |
| Julius Futterman | Schematics |
| Ken's Electronics | Tubes, Parts |
| Lampy Elektro-nowe | Transformers, Schematics |
| Lee Jaehong 6C33C OTL | Schematic, DIY Tube Amplifier |
| Lidstrom Audio | Information, Schematics |
| Magnatone The Unofficial Ampsite | Schematics, Tube Guitar Amplifiers |
| Magnetic SA | Transformers, DIY Tube Amplifiers |
| Marshall Transformer Codes | Information about Tube Audio - Articles, Schematics, Manuals |
| Music Electronics µArchive | Schematics, Information, Links |
| Onkel frihu's Community das Forum | German Forum about Tube Audio |
| Pispola Patrizia | Componenti elettronici |
| Prowess Amplifiers | Schematics |
| Schaltungsdienst Lange o.H.G. | Schaltpläne, schematics |
| schematicheaven.com | Schematics |
| Steve's Tube Pages | DIY Tube Audio, Schematics |
| The Circuit Archive | Schematics, Forum |
| The Tubelar Page | Schematics, Information |
| Triode Electronics Online Catalog | Tubes, Parts, Tube Data, Schematics, Links |
| Tube schematics and more | Schematics |
| Tube Swap Homepage | Links, Dynaco Tube Schematics |
| Tubebuilder.Com | Tube Amplifier Kits, Tube Datas, schematics |
| Unofficial Dynaco Home Page | Museum, Schematics |
| Vacuum Tubes, Inc., Electron Tubes | Tubes, Sockets, Manuals, Schematics, Information, Radios |
| ValveHeart | Tubes, Schematics |
| Vintage Ampeg Amplifier Schematics | Tube Guitar Amplifiers Schematics |
| Vintage Tube Amplifier Schematics - AmpsLab | Schematics |
| Wade's Audio And Tube Page | Tube Amplifier circuits and information |
| Zeuslab | Schematics |