Reply to Bang!

So I'm playing my usual Thursday evening , and mid-way through my set, I hear an almighty BANG. Everything's still working, so I'm desperately trying to work out just exactly what it is that blew up on me... then I notice my mixer smells VERY strongly of burning.

And yet, everything's still going strong :-/ going to have to disassemble it when I get home, mebelieves.