Cap life span?

Many suggest changing electrolytic caps every 15-20 years. This is an estimate, like tube life, it can vary. My amp is 19 years old and I just sent it to the manufacturer and wanted them to change caps, they told me that the caps looked to be in great condition, and tested well also. They recommended not changing them, I took their recommendation.

Tutate: this question has been thoroughly discussed. Search the Forum for threads.

If you look at the datasheets of aluminum electrolytic caps; you'll find that their expected life spans are noted in hours, at a certain temperature. Some datasheets even list an expected shelf-life. These sites each mention different ways caps age/lose their values: ( http://www.elna.co.jp/en/capacitor/alumi/trust/index.html ) ( http://chemi-con.com/u7002/life.php ) Some good info here: ( http://www.hans-egebo.dk/Tutorial/electrolytic_capacitors.htm ) If the amp is approaching the 20 year mark: A cap change is a good preventive maintenance measure, and you'll probably notice improved performance in the system's bass & overall dynamics.

If leaking then replace. Sometimes a new one is bad. If all is working and specs fine leave it alone. I like to change mine when I get a new tube amp, but this an ocd indulgence rather than a sonic necessity. Jallen

When talk of replacing electrolytic caps comes up on this and other forums. Most people are concerned with the larger can style caps found in amps and preamps. Overlooked are the dozens of small value electrolytic caps such as those found in cd players, remote controls, secondary power supplies etc etc. Looking at a spare cd transport I have in storage (that is 20 yrs old) I see about 30 small value electrolytic can style caps soldered to the circuit board. Do I worry about these caps being dried up? No, and I dont worry about the large caps in my 20yr old amp, 30+yr old receiver and many other pieces of equipment either. Never had a Electrolytic cap go bad on me. However, I never let my equipment sit dormant for any prolonged lenght of time. Including hooking up the spare transport and running it occasionally. Which I think is probably a key factor in prolonging the life of electrolytic caps and avoiding failure.