Upsizing Capacitors

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. 

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.

I used a car analogy in another thread, have always had the same logic on auto "upgrades". Take wheels for example, somewhere you have an engineer who dedicated their LIFE to the field and maybe months/years on any specific car only to have someone think they know better - it's a valid point!

On circuit design, absolutely. What prompted my post is every other capacitor DIY story, we have people increasing capacitance! On average, more negatives than positives (pun totally intended)..