Should I Contact Joh Curl And How? re:A21

[Matador]

Dear Comrades,

I few months ago I acquired A21 amp. It really is a very nice amp, and I am absolutely satisfied. However, a while back, I found out a few differences between the amp pictured at Audio Advisor's web cite and mine. In the AA's photo of the amp's inside I clearly see that it uses four Elna 80v 25000uf capacitors, while mine has four Rubycon 100v 22000uf caps. Now is this something I should be concerned about and ask Mr. Curl, or you, guys, can give me simple explanation for my peace of mind. I just want to know if these two amps sound different.

Thank you very much!

[r100gs]

Richard will be able to answer your questions. richard@parasound.com

[Glen B]

John Curl posts on Audio Asylum fairly regularly. Manufacturers often make parts changes and minor improvements during an amplifier's run. The differences you point out are not major.

http://www.audioasylum.com/index.htm

[Chris D]

That's where I've found him before in the past, can talk to him there.

[Matador]

Thanks, guys. I called Parasound long before I posted here, and was told that they ran out of the Elna 25000uf caps in 2005, and since then they've been using the other caps. That makes sense, but I don't know how my previous two A21's (they turned out to be defective) had that damned 25000uf Elnas... Anyway, now it doesn't matter since I've been assured here and somewhere else as well that the difference is really very small, and won't affect the sound in a negative way. Of course, it would be nice to hear the man's (Curl) opinion on this, but I guess it is not a matter of great importance now.
Nice thing, though, is that both Parasound and AudioAdvisor stand behind their product, and they replaced the defective units without any hassles, great service. Thanks again for taking the time to respond.

[Peter Nielsen]

There are so many things that have more effect overall. Temperature and time kills capacitors.

The lifetime of a capacitor is usually classified as the time when the capacitors value has decreased by 20%

Did you know that the lifetime of electrolytical capacitors is typically 3000 hours @ 85 degrees Celsius? For every 10 degrees less, the lifetime is doubled. So at 75C you get 6000 hours, 65C 12000h, 55C 24000h, 45C 48000h and 35C 96000h...

At 85C you would kill your capacitors in only two months(!). At 45C you get 5 years out of them...

Stocking lifetime of capacitors is often as low as 1000h @ 85C, so even if you got hold of 5 year Elnas, you would not want to use them. What you want is factory fresh capacitors that were manufactured recently....

[Johnloudb]

John Curl is posting on his blowtorch thread at diyaudio.com most everyday as also:

http://www.diyaudio.com/forums/solid-state/146693-john-curls-blowtorch-preamplifier-part-ii-213.html