What to look for when capacitor(s) decline?
Electrolytic Capacitors will change value and likely start to ooze (leak) fluid which sucks and the cleanup is usually harder than the actual Capacitor replacement.
I havenāt ever seen Polypropylene Capacitors leak or change value. Same for the Mylar Caps.
Also a cheap LCR meter will help provided the Cap is not in Paralell with something else in the circuit.
My 2 centsā¦Others may want to chime in and correct me or add better suggestions.
thanks, I should have focused on what I meantā¦sound qualities
Iāve heard that electrolytic capacitor have a life expectancy of about 20 years.
At 20y/o they should be replaced with something of the same value.
RE: sound quality degradation with electrolytic capacitors in a power amplifier, the capacitance value will slowly decrease which reduces the HV bus filtering. You may notice a less defined quality to the bass especially as that usually requires the most power from the amplifier. If the HV bus sags due to lowered filter capacitance the voltage and current delivered to the speaker will reduce softening the response.
Also, that 20 year suggestion above is a good general rule. I leave my amps on 24/7 which should increase capacitor life because they are not charging and discharging each time you power cycle. You also donāt have to worry about capacitor āreformingā as you would if you leave your amp off for a long time.
Wait, do you mean like rectal bleeding? A lisp? Warts?
I donāt think failed capacitors do any of that.