IMO, almost all audio equipment uses generous PS cap values to keep ripple voltage low, plus it never operates at full power, save for the test bench. The ripple current rating of almost any cap with the right value will invariably be greater than the actual demands. Unless you listen to that modern boogie woogie music at unhealthy volume levels.
Naturally, the specs for the new parts should always be checked, but we often don't have a spec for the specific parts used in vintage units, especially if they were customs for the manufacturer.