Links

http://www.duncanamps.com/ Duncan's Amp Pages.  Excellent source of infomation about all things tube.

http://www.audioasylum.com/index.htm Can't live without these guys. 

http://www.provide.net/~cfh/   Antique Vintage Guitars Info - good source for dating vintage guitars

http://www.notecannons.com/ Gorgeous site with info, pics and sound clips of National-Dobro instruments and amps

http://www.well.com/~wellvis/gitinfo.html Brad's Page of Steel.  Everything lap steel.

http://online.physics.uiuc.edu/courses/phys498pom/498emi_lap_steel_guitars.htmlhttp://online.physics.uiuc.edu/courses/phys498pom/498emi_lap_steel_guitars.html

Lap steel site - some 30s and 40s amp pics

Pics and info on Rickenbacker Amplifiers

http://jzu.free.fr/rick/amp/TRR.html 

http://www.rickenbacker.com/history_early.asp

Paul Tutmark and the History of Audiovox

http://www.historylink.org/essays/output.cfm?file_id=7479
http://www.danbyrnes.com.au/hotm/1930s.htm

http://www.b0b.com/infoedu/tutmarc1.html

National, Dobro, Supro, Valco History:

http://www.vguitar.com/features/brands/details.asp?AID=1090