[morzh]

Ron

Depends what electrolytic we are talking about.
Early power supplies often times had simple rectifier bridge - electrolytic cap structure. Given the fact that the solid state uses low voltages and high currents, ESR and Ripple are not unimportant. And because the current is high the capacitances there are huge, 10,000uF not being unusual.
You want to minimize discharge of a cap especially so when you have large volume/high power peaking (which especially with modern music happens a lot) and you need to provide stable power while drawing large current. In transistor amps the amplitude of a signal becomes comparable with the power voltage and so every change in that voltage affects your output a whole lot more than it does with tubes.

Luckily very large electrolytics almost by default have quite large ripple currents. Minimizing ESR by choosing switching grade caps will help further.

if you buy through a legit major catalog (Mouser/Digikey) they all carry practically only legit major cap manufacturers. Of course even major manufacturers, as we know, sometimes have problems, but the likelyhood of it is that much smaller.
Nichicon, Chemicon, Rubycon, Panasonic.