| Chicago Joe's Tube Information Page | Information about Tube Audio - Articles |
| Focal Jmlab | Speakers |
| J.C. Verdier | Tube Amplifiers |
| JA5GYU | DIY Tube Amplifiers |
| JAC-MUSIC | Tubes |
| JacobVisser.nl | Links |
| Jadis | Tube Amplifiers, DAC's |
| Jaeger-Meisterelectronics | Tubes, Tube Amplifier Service |
| Jameco Electronics Electronic Components | Parts |
| James Audio | Tube Amplifier Service |
| Jannes homepage | DIY Tube Audio Site, Ham Radio |
| Jantzen Audio | Foil inductors for crossovers |
| Japan Audio Tubes | Links |
| Japan Quad Fan Club | Audio Clubs |
| Japanese Tube Forum | Forums |
| JAS Homepage | Japan Audio Society |
| jazz guitar pages - tube amps | DIY Tube Audio Site |
| JBL Professional | Speakers |
| JC Audio | Retailer |
| JCM | Tubes |
| JE Labs Homepage! | DIY Tube Amplifiers |
| Jean Maurer - Lectron | Tube Amplifiers, Speakers |
| Jeff Korneff Custom | DIY Tube Amplifier |
| Jena Labs | Retailer |
| Jensen Capacitors | Capacitors |
| Jensen Tools | Tool Kits, Test Equipment |
| Jensen Transformers, Inc. | Transformers |
| Jeremy Epstein's Home page | DIY Tube Amplifiers |
| JH Brandt Enterprises | Tube Amplifiers, Tube Guitar Amplifiers |
| JH Sound Hi-FI Tube Amplifiers | Tube Amplifiers |
| Jimcom | DIY Tube Amplifiers |
| JimCom Tube and Electronics Hobby Pages.. | DIY Tube Amplifiers |
| Jim's Citation Amp and Vacuum Tube Page | Tubes, Information |
| Jingau Enterprise | Tubes, Transformers, Parts |
| Jinvina Audio Company | Tube Amplifiers |
| Jiya-noda | DIY Tube Amplifiers |
| JJ Electronics | Tubes, Capacitors, TubeAmplifiers |
| JLVillabona | Vintage Radios, Tube database |
| JM Audio | Retailer, Vacuum Tubes Retailers New and NOS Tubes |
| JMH's Virtual Valve Museum | Museum |
| Joe's Tube Lore | Information about Tube Audio - Articles |
| Jogi's Forum | German Forum |
| Jogi's Röhrenbude - Röhrenradios und mehr | Old Radios and more |
| John Harper | Private Tube Audio Sites |
| John's Radio Pages | Vintage Audio Gear, Scott |
| John's Radio Web | Tube Radios & Related Vintage Items |
| Jolida | Tube Amplifiers |
| JoMama | Tube Guitar Amplifiers |
| Jongwoo's Page | Links |
| Jonka.net | Forums, Links |
| Jonz Valve Page | Tube Radios, Links |
| Judybox | Tube Guitar Amplifiers |
| JuicyMusic | Tube Amplifiers |
| Juke Amplification | Tube Guitar Amplifiers |
| Jukebox Friday Night | Tube Amplifier Service |
| Jukka Tolonen | DIY Tube Audio |
| Jule Amps | Tube Guitar Amplifiers |
| Julius Audiophile Homepage | DIY Tube Amplifiers |
| Julius Futterman | Schematics |
| Junji Kouchi Tube Amplifiers and Music Sources | DIY Tube Amplifiers |
| jyk listening room | Private Tube Audio Sites |