01-18-2014, 09:17 PM
While ESR in general can be important, the initial spec of the capacitor is not as critical as how the ESR increases over the service life of the equipment. As the capacitor ages, its actual ESR increases due to electrolyte evaporation.
A high temperature rated 105C cap will last longer at normal operating temperatures than a 85C rated one. For every 10C reduction in temp from the rated value, the life doubles, so the higher temp rated cap has an inherent 8 times longer life advantage at lower operating temps.
Most electrolytics fail in audio equipment from electrolyte loss due to age and elevated temperatures. The hotter it gets the shorter its life, so you want the highest temp rated part even though it may never reach the rated temperature.
Now if you buy a cap with low initial ESR and a high temp rating, that is the ideal solution, but typically it may cost a bit more.
A high temperature rated 105C cap will last longer at normal operating temperatures than a 85C rated one. For every 10C reduction in temp from the rated value, the life doubles, so the higher temp rated cap has an inherent 8 times longer life advantage at lower operating temps.
Most electrolytics fail in audio equipment from electrolyte loss due to age and elevated temperatures. The hotter it gets the shorter its life, so you want the highest temp rated part even though it may never reach the rated temperature.
Now if you buy a cap with low initial ESR and a high temp rating, that is the ideal solution, but typically it may cost a bit more.
