Just a general word about capacitors:
The absolute value of most capacitors in audio amps is not important, as most are decouplers, either low or high frequency. For these capacitors you can always go up in value, but make sure your circuits are balanced (ie negative and positive supply rails have the same value capacitance). Also, you can always parallel capacitors to make up a value, but not put them is series.
It is only frequency response shaping capacitors and Zobel network capacitors that need to be accurate to within 10%, or better as specified.
Within reason, you can also go up in value for coupling (in signal) capacitors too.
In terms of working voltage, it is best to operate solid capacitors no higher than 90% of their voltage rating, taking into account temperature. You can always fit a higher voltage solid capacitor but beware that some high voltage solid capacitors bring extra baggage that may make them less suitable for audio work.
It is best to operate aluminum electrolytics between 60% and 90% of their rated voltage, once again taking into account temperature. The reason for this tighter voltage range for aluminum electrolytics is to keep the insulating film well formed and to ensure that there is sufficient voltage to blast away weak areas and give a nice clean insulating barrier. This does not apply to tantalum electrolytic capacitors.
In terms of reservoir capacitor ripple current, the less the better, and do not exceed the maximum rating, taking special care to derate the ripple current in accordance with temperature effects which can be quite large.
Often it is not realise that aluminum electrolytic capacitors are lifed components and should be changed after the data sheet specified period has been reached- typically 5,000 hours. This is especially applicable to reservoir capacitors, have a hard life. Apart from military and special equipment though, this is rarely done. Aluminum electrolytic capacitors' are available in 85 deg C and 105 deg C rating. Roughly for every 10 deg C increase in temperature the life is halved; it is the actual electrolyte temperature that counts, not the ambient temperature.
Some cap references.
https://www.mouser.com/pdfdocs/ELNAReliabilityAlumElecCaps.pdf
https://www.cde.com/resources/catalogs/AEappGUIDE.pdf
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https://en.wikipedia.org/wiki/Electrolytic_capacitor