Don't mess with tube amps. If you touch the wrong capacitor without knowing what you're doing you could really injure yourself.
That said, there's plenty of safe audio equipment out there to experiment with. Before I got an EE degree, I was building effects pedals in my basement.
Regarding effects pedals specifically, you won't end up saving much money versus buying one off the shelf due to economies of scale, but you can make something really fun and unique by yourself pretty easily.
Definitely agree! Tube or solid state alike. Both can house some dangerously-sized caps.
Guitars are also quite safe and relatively forgiving as you keep the grounding intact.
That said I only mentioned amplifiers as the GP was referring to hacking on cars—so I imagine the project wasn’t targeted at complete beginners when they were wondering about equivalent projects. And draining caps before working on them is one of the first things any tinkerer learns—or learns to stay away from.
That said, there's plenty of safe audio equipment out there to experiment with. Before I got an EE degree, I was building effects pedals in my basement.
Regarding effects pedals specifically, you won't end up saving much money versus buying one off the shelf due to economies of scale, but you can make something really fun and unique by yourself pretty easily.