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.