Smoothing Cap: ESR or Capacitance


Am selecting smooting caps for my Amp but have restriction of space (recap purpose).
I have selected either BC058 or BC056.

The original was using 4,700uF customised BHC caps.

For the space I can only get BC058 at 3,300uF to fit, ESR at 57mOhm, and Z at 33mOhm.
Alternative is BC056 at 4,700uF but the ESR is higher at 65mOhm and Z at 52mOhm.

So which is better?
Hi Andrew,
Thanks for the reply.
I really don;t knwo what is the current draw but this is a 50W amp.
The existing cap has Ripple spec at 2.52A and the BC has 3.14A, so I guess except for the Capacitance, the BC is better than the existing one.

Anyway I'll go for the the 3,300uF and if they sound worse then I'll just fit the old one back.