Hi Everyone. I'm new here. I have a couple of sites that have a vast collection of pro audio schematic diagrams from my bench tech days and are all free to download. schematics.ca and schematics-free.com have free electronics schematic diagrams downloads for pro audio gear such as guitar amps, power amps, vintage tube amps, musical gear like keyboards and effects pedals and repair manuals. A must for road musicians (like myself) to have schematics for all their gear in case you get in trouble while touring.