Power supply caps

OK, I'm not trying to start an all amps sound alike type thing, but I would like to know if anyone has actually heard this. Not theory or speculation, but actually replaced caps on their equipment.

Will upgrading/replacing old caps in a phono pre-amp's separate power supply have any effect on sound? I'm getting ready to recap my 20+ year old phono pre and wonder if the caps in the power supply should be run of the mill or high quality? If they make a difference, then fine, but if the PS caps won't have an effect on sound, I don't want to waste the money.

Thanks for the help.
I have upgraded the caps in my previos phono preamp. I had already upgraded the op amps, resistors, coupling caps and regulators. So I can definitively speak to the effect of just changing power supply caps.

In my case the backround got blacker as in the very low level detail was not lost or masked in the backround noise.

Also, the high frequencies lost an annoying zingyness. It was like I had changed from an agressive metal dome tweeter to a smoother silk dome type.

In my case the existing caps were very cheap and I replaced them with Blackgates.

I will also conceed that I may not have heard much of a difference if I had not already upgraded virtually everything else in the circuit.

Ofcourse, YMMV
I replaced power supply caps in Cambridge Audio A3i amp a while ago. Theoretically it should not make any difference since amp was only few years old (unless Canadian dealer sold me very old amp in new box) but it had pronounced effect on the bass. It became taut and more dynamic.

It depends on temperature of your amp and amount of time it was powered on. Every 10deg C cuts life of capacitor by factor of 2. Good capacitor can last in room condition for 50 years but there is always some temperature increase. Aging of electrolytic capacitors is simply drying out of electrolyte causing increase in ESR (effective series resistance) reducing damping effect amplifier has on speakers. Good replacement caps should have low inductance and low ESR. If old capacitors have wires soldered to them make note where. Load should be connected to last capacitor while rectifier should be connected to first one (opposite side of the bank). Soldering wires in wrong place is common mistake that might end up in audible hum.
Thanks guys. I have been slowly coming to the conclusion that literally everything matters, so I sort of figured that the PS caps would matter. I'll probably replace the PS caps before replacing the ones in the pre, since the ones in the pre aren't exposed to much heat. Then I will be able to tell for sure how much difference the PS caps make.