Power supply caps

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.

Not all caps are equal in size either so do your homework and make sure they will fit.

I'm having trouble finding caps with the correct values. I need 4700uF 50VDC, 470uF 63VDC, and 1000uF 25VDC. Couldn't find them on Parts Connection, Parts Express, or Madisound. Any suggestions where to find them would be appreciated. I'm doing googles now to try to find a source.