Upsizing Capacitors

I've upsized large 4 filter caps on Accuphase E202 integrated amp on capacitance, temperature and voltage. The idea is to keep discharge time relatively similar. If the FACTOR of discharge time goes like 2...3x faster through the resistor, you'll need to replace it to the larger resistor. In my case the difference was tolerable only by 12% faster. Therefore I didn't change any other circuit components.

I have to assume we are talking about filter caps...

You have to be careful as bigger caps = more current draw and more stress on the transformer and upstream components.

Personally, reduced ESR and higher temperatures are a bigger factor in upgrading these than the capacitance. Higher temperature caps have longer endurance ratings generally speaking, so if I can fit a 105C cap in place of an 85C cap I will.

Best practices: If it works, leave it alone.

People spend months or years designing amps and other people who think they know better want to "improve" on the design. Where's the facepalm emoji? Sheesh.

Measure the capacitors with a good lcr meter to see if they have degraded due to age 

Replace if they are more than 10% low. Otherwise leave them be.