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  • fererencz89

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    válasz Dißnäëß #110303 üzenetére

    Szerintem itt valami rosszul van értelmezve. Hangváltóban jellemzőbb, hogy a szivárgás teszi tönkre az elkót, mint maga a használat.

    "What absolutely kills electrolytic capacitors (such a main PSU caps) is temperature. A typical modern electrolytic cap will have it's lifetime specced by the manufacturer at something like 2000hrs at 105degreesC. Looks like just 3months at full load and temperature!

    However the actual useful lifespan (usually taken as 'to the point where Equivalent Series Resistance doubles) is an inverse-exponential function related to running temperature, with lifespan roughly doubling for each 10degreeC drop below rated temp. This is the caps' internal temperature, which depends on ripple-current loading as well as environmental temperature.

    So at 40degreesC that same cap should last c. 64*2000 or about 14years in continuous use. Now perhaps one can see why Naim's rule of thumb of replacing main PSU caps at 8 years is about right - it's about the useful lifespan assuming for full ripple current , 24hrs a day, at around 45degC internal temp. It agrees with basic chemistry.

    Stick that same cap inside, say, a Class A amp chassis exposed to heavy ripple (due to the constant idle bias) and so running at 60degC and it may only last , on average, 3years or so.


    Use an electrolytic cap in a speaker crossover though and I suspect the thing die from simple loss of electrolyte via the seals over, say, 15+ years. Domestic use / listening levels are very unlikely to ever run such things warm let alone hot. I think you'd be replacing drivers weekly to get even in that ballpark!"

    Nem szotkam hibázni.

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