Rectification

Like me, when you're contemplating rectification, you probably only think of solid state or valve, right?  Something like this:

Or maybe this:

But there is another type.

Mercury arc rectification is by far the most impressive:

The two glowing orbs on the right are the mercury arc rectifiers at Kempton Steam Museum and convert 3 phase 415VAC into 200VDC @ 100A.  Impressive, but possibly a bit big for my amp.