The Blue Guitar Very good info on mods. Lots of really good tube amp circuits and moreSome Music, Electronics Links
Jon Tirone's Music and Electronics Page
These are just a few of the many good links on the subject. These are some of my favorites or places to get info.
Vacuum Tube Guitar Amp Links
The Blue Guitar Very good info on mods. Lots of really good tube amp circuits and more
AMPAGE - Tube Amps/Music Electronics If you want to learn about guitar amps and music, electronics, just hang around this site for while. Excellent discussion groups.
Larry's World of blues (Lots of good schematics)
Triode Electronics Tons good info, circuits and links
The Fender Amp Field Guide The place to go for Fender Schematic and info
Vox Downloads Vox Guitar Amp schematics to your hearts content
Tube Amps For Beginners The name says it.
Eddie Ciletti Wide variety of info and good links
PAiA Electronics A few DIY projects
Guitar Effect Pedal Info
GEO - the guitar Effects Oriented Web Page good info and circuits
Guitar Effects Schematics - AMZ more info and great collection of schematics
Aron Nelson's Stompbox Page great site for pedals
Lazyfinger circuits and PCB layouts
Other Electronics and Audio Electronics Info
Professional Sound system (PPS)
QSC Technical Services Library