Comment by peteri

Very true, I remember many years ago when working at Soundcraft, there was a loud bang from next door as a small mixing desk with builtin amp was powered on for the first time[1].

Large electrolytic smoothing caps fitted the wrong way round, the smell is horrendous.

[1] By Douglas Self who has an excellent page about subjectivity in HiFi http://douglas-self.com/ampins/pseudo/subjectv.htm