I really like how Fender is shipping the schematic with their amp (I hope they still do it). That being said, guitar amps, specially tube amps are indeed extre

I really like how Fender is shipping the schematic with their amp (I hope they still do it). That being said, guitar amps, specially tube amps are indeed extremely dangerous, not only the caps, but also the 300, 400 and sometimes 500 volts DC around the tubes. You need to be extremely cautious when handling these, specially if they are powered and opened (to check voltages in various points of the circuit for example). That being said, I've not seen a lot of guitarists actually opening and servicing their amp themselves, even if the circuits tend to be quite simple and easy to maintain/repair (few components, no SMD).