Capacitor lifespan and audio quality

[KHashmi316]

What happens to audio quality as capacitors -- and, notably, aluminum electrolytic capacitors -- approach and exceed their rated lifespan? Should one be as concerned about replacing them as, say, vacuum tubes?

(see this link for Elna's take on this issue)

[EchoWars]

Depends on the age, the amount of ripple current the cap is regularly subjected to, and the ambient temperature in its environment. All of these contribute to the aging of the cap.

My own rule of thumb: if it's 15 years old or older, replace it. When it is in doubt, replace it. If something weird is happening on that board, replace it.

New low ESR caps (Panasonic FC and FM and Nichicon PW and HE) are so much better than anything used in older gear that the reasons NOT to replace them pale in comparison to the benefits.

[AMV8]

Hi

I have been rebuilding some equipment that I originally built in 1980 at which time I used Elna electrolytic capacitors and also ALS20 electrolytic capacitors.
I found a slight improvement from chaging the elna capacitors. I did not find any change from changing the ALS20 A capacitors. In fact in one power amp I put the ALS20 capacitors back in as they sounded better.
Plastic capscitors ( such as polcarbonate, polystyrene etc ) do not seem to age but electrolytic ones do seem prone to drying/leakage.
If possible I use 105 degree capacitors and not 85 degree capacitors. The higher temperature rating gives them a much longer useful life as they are operating so much more within their temperature rating. I think that is why the ALS20A capacitors were still working fine after 20 years.
The last caps I bought were Kendeil and they have a rated life of 10,000 ours at 105 degree. So as long as they do not dry out ( in central heating ) they should last some time.
When storing capacitors at home,before use,I store in air tight plastic bags to avoid drying out if possible.
I hope this helps.
Don

[KHashmi316]

Originally posted by AMV8
Hi

I have been rebuilding some equipment that I originally built in 1980 at which time I used Elna electrolytic capacitors and also ALS20 electrolytic capacitors.
I found a slight improvement from chaging the elna capacitors. I did not find any change from changing the ALS20 A capacitors. In fact in one power amp I put the ALS20 capacitors back in as they sounded better.
Plastic capscitors ( such as polcarbonate, polystyrene etc ) do not seem to age but electrolytic ones do seem prone to drying/leakage.
If possible I use 105 degree capacitors and not 85 degree capacitors. The higher temperature rating gives them a much longer useful life as they are operating so much more within their temperature rating. I think that is why the ALS20A capacitors were still working fine after 20 years.
The last caps I bought were Kendeil and they have a rated life of 10,000 ours at 105 degree. So as long as they do not dry out ( in central heating ) they should last some time.
When storing capacitors at home,before use,I store in air tight plastic bags to avoid drying out if possible.

Thx for your reply.

I have some equipment that is on all the time. Some feel electronics perform better/"last longer" this way. But with respect to electrolytic caps, I'm not sure always-on is such a good idea. A lot of us may have upgraded/sold/traded-in equipment long before cap lives are "expired". This is especially true for rapidly-evolving technologies, such as DACs and CD/DVD players. But some of my equipment -- notably amps and pre-amps -- is modular and does not become outdated very quickly. So cap longevity may be more of an issue here.

[AMV8]

Hi

I think that the life of a part, especially a capacitor or semiconductor is considerably extended by running at low temperature and at below the current rating. For example a capacitor in a class a power amp may run at 50 or 60 degrees centigrade. If its life is rated at 85 degrees it will not exceed its 85 degree life by much. However if it is life is rated at 105 degrees it will be working long after its rated life.

Don