Your amp will be fine as long as you use it for lounge-room listening. Just don't use it in pro situations, e.g. a wedding reception or large party (50+ people). Please!
(But if that cap across the transformer secondary is only DC rated, not AC, you can expect it to explode. Might take a couple of years, if you're lucky. I had one last five years before I learned about "X-class" mains rated capacitors.)
Glad I'm not into power or audio electronics. :)