85°C caps rated for 2000h in an amp running @ 35°C [95°F] have an rated life of 8000h.Oops. 2^5 = 32. 2000h rated are 64,000h @ 35°C. 32k days @ 2h/d ≈ 88y.
However other factors limit the life other than temperature, so 15y is a safe limit.
Fans on amps.
Fans on power amps are rarely quiet enough for listening to acoustic music. One friend had a fan cooled power amp and when we tried to listen to solo violin it was like attending a concert with a DC-6 winding up for take off in the room. Had we been listening to loud rock it probably wouldn't have mattered. You can get away without fans if you have proper heat sinks, but that is expensive. Take a look at the pics of these Classe Class A amps: https://www.aussieaudiomart.com/details/649274239-pair-of-classe-dr3-vhc/images/1228060/ The amps put out into the hundreds of watts of heat just sitting there (a bit less if they are converting some of the current into sound. Another friend had some fan cooled Crown (commercial) amps - I couldn't listen to them with the fans going beside us. |
The amps mentioned sound like PA amps which are not designed for HiFi home use. Any system that is audible when not playing isn't HiFi. There are many sound apps available for smart phones. Broadband, ambient noise should be below 40db or below 30db 1/6octave. If there is any delta between amp off and on at 1m, the fan is TOO LOUD!! |