Guitar Amplifier Schematics - Guitar Nucleus Guitar Amp Schematics. WARNING - If you are not a qualified technician please do not attempt any repair you are not confident with. Amplifiers (especially tube amps) contain high voltages that can kill ! Even when unplugged the capacitors can still contain a substantial charge and must be discharged before attempting any work. Guitar Amp Schematics - wwwubestore Guitar Amp Schematics. Here we've listed our collection of guitar amplifier schematics. All are available for free download. If you need a guitar amp schematic for your amp repair that is not listed here, contact us and we'll try to locate it.