Interesting Ultra-Fi Sites
No 1996 to 2006 Lynn Olson.
Nostalgia Air http://www.nostalgiaair.org
Online antique and Vintage radio references offering free online schematics, manuals, tube data, references and more! Offers a tube substitution and characteristics guide, schematics and manuals, and an active technical forum,
Frank's Electron Tube Pages http://www.tubedata.info
A big tube data site with emphasis on foreign tubes. Includes substitution guides and lots of other tube information.
Tube Collectors Association http://www.tubecollectors.org
The Tube Collectors Association is established to support and encourage the collection of electron tubes of all types and historical periods. The TCA provides a forum for sharing information on the development, manufacturing, trends in design, specifications, and historical relevance of electron tubes. The membership of TCA is dedicated to the non-commercial collection of electron tubes and the preservation of electron tube history. TCA prints a magazine six tuimes per year. They also offer on site tube ads and a tube database search engine.
Virtual Valve Museum http://www.tubecollector.org
This is a site by a tube collector in the UK. It is quite an undertaking an a serious reference for anyone interested in vacuum tubes. There are currently 2730 valves in the collection, 2295 on the website.
The National Valve Museum (Virtual) http://www.valve-museum.org
This museum exists to preserve our heritage of the early days of the electronic age when the wireless set had to warm-up, and, viewed through the perforated back of all electronic equipment, could be seen the dull red glow of the valves inside. This is a very large, easy to search index of 2,701 tubes with nice pictures and other tube related resources too!
Duncan's Amp Pages - Free Schematics & Tube Data http://www.duncanamps.com
There is a nice list of tube music, guitar, and hi-fi amplifier schematics here that are available for free download. There is also a wonderful tube data chart database. Just enter the tube number and hit the button!