This a an interesting design f**k up. The initial design reissue with the PCB had close mounted components and PCB mounted valve sockets. The capacitors are (were?) fitted, standing, flush to the PCB. Turns out, it all got ‘too hot’. So they fitted a fan blowing air over the transformer/ capacitor area to try to keep components in a thermal range to try to prevent a load of ‘in warranty’ repairs coming back. Blowing air INTO the amp, not pushing air out. Does it actually do anything useful? Many people have written passionately either way! The most polite way to describe it - an unconventional design from a thermal design perspective.
The ‘59 original, no PCB and no fan. And yes - they get hot.
The point is, if you want to remount it, the ‘correct’ orientation is blowing air over the transformer area. But there are plenty of people that have flipped it round, and plenty of people that removed completely - which I don’t know is a good idea….
Hope this is interesting! Is the fan an afterthought? Yes. Is it testament to poor design choices? Yes - obviously! Does it do anything actually useful? Debatable. Does it matter which way the air blows? Not really, no.
