Amplifier question

I've got some of the short, really old Magneplanars. (I picked them refurbished.)

This is the HK-870 amplifier I'm using to drive them. HTML is not allowed so you'll have to copy and paste:

I want to understand what I'm looking at: Forgive me for asking what's an obvious question to you electrically-minded types, but is this a two-stage amplifier? Why four sets of capacitors?
All the big caps are PSU (power supply unit) filter/smoothing caps... very essintial part of an amplifier. Do you want to upgrade these? Go right ahead...

Best of luck,
Dewald Visser