How long electrolytic caps last? - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 25th April 2002, 12:38 AM   #1
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Default How long electrolytic caps last?

I have just removed some electrolytics from my preamp with a thought that I might use them in my SOZ. After I checked them I was quite dissapointed. They measure nothing and don't get charged when I connect them to PS. They've been in a preamp for 7 years and the power was always on. Four caps in parallel, 3,000uF/40V ea. Is that normal? I've heard about caps aging but never observed it first hand. BTW I still have the same caps which I never used and they measure perfectly. The ones that are more yellow are the defective ones.
Thanks for your advice.
Attached Images
File Type: jpg caps.jpg (67.3 KB, 695 views)
  Reply With Quote
Old 25th April 2002, 02:36 AM   #2
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
I'd say about 10 -15 years, but with the improvements in capacitor technology you could get a whole lot more capacitance in a smaller space with lower ESR to boot, maybe it is time to replace those cans.

Jam
  Reply With Quote
Old 25th April 2002, 02:47 AM   #3
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
I'd say about 10 -15 years, but with the improvements in capacitor technology you could get a whole lot more capacitance in a smaller space with lower ESR to boot, maybe it is time to replace those cans.

Jam
  Reply With Quote
Old 25th April 2002, 09:37 AM   #4
diyAudio Member
 
Join Date: Jan 2001
Location: Scandinavia
Default There are many factors

1. Technology: Dry electrolytics last "forever"
2. Wet ones: Depends on a) physical size (takes longer to evaporate), temperature exposed to, core temperature, construction of seals.
3. Overloading/loading -- voltage and current.

Caps that are smaller than .75" diameter should not be trusted for more than 10 years unless particularly high quality or if kept at low voltages, or better still low currents.

If they have not been used for a while, you might want to charge them up 10 120% of rating through a resistor so that current is kept low + leave with voltage on for 10-15 minutes. You could use say 100-1000 Ohms, it is not critical, but you probably need a high power unit.

Petter
  Reply With Quote
Old 25th April 2002, 02:53 PM   #5
alvaius is offline alvaius  Canada
diyAudio Member
 
Join Date: Feb 2002
Location: Toronto
Electrolytic life is highly dependant on how you use them. The big killer is heat. Heat can come from both external sources and internal sources. If you put those in a power amp that runs hot, that could be an issue. In a low temp pre-amp, that should not be so much of an issue. Internal heating is of course from losses in the cap from in-circuit use. One thing to watch is that you are not exceeding the ripple current. That can drastically shorten the life! If you look at electrolytic data sheets, they generally have a stated life at a given temperature. Reduce the temperature, and that life increases significantly. Not too long ago, most were rated at 85 celsius. Now, some of the better ones are rated at 105 or 125 celsius. That is better in terms of life, you still need to determine how they will behave in your system, though most of the high temp ones are also very low ESR and hence may make a good power supply capacitor.
  Reply With Quote
Old 26th April 2002, 03:52 AM   #6
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
I read somewhere (EW magazine I think) that electrolytes can 'wear out'.
In my servicing work experience, cans mounted on their sides or rubber bung downside last better - maybe the rubber dries and allows leakage.

Regards, Eric.
  Reply With Quote
Old 26th April 2002, 04:34 AM   #7
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Jam,
After your advice I decided to use more modern electrolytics in my upcoming SOZ project, however, I'm not totally sure they are better.
Attached Images
File Type: jpg zen.jpg (67.9 KB, 537 views)
  Reply With Quote
Old 26th April 2002, 08:05 AM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Default Time of life

Surf to ELNA and Philips (BC Components) for nomograms over life expectancy. They are very good but I haven't got the exact URL.

But as a conclusion: Don't use old "used" caps in new projects. Go for brand new. You don't need "Computer grade" types.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 26th April 2002, 11:28 AM   #9
diyAudio Member
 
mefinnis's Avatar
 
Join Date: Feb 2001
Location: Adelaide, Australia
I've had quite a bit of luck with surplus caps, but they definitely have a life.

BTW ..... do you have stocks in aluminium ??????

2nd point ..... don't go overboard with filter caps in SoZ, because of the design it is far less susceptible to rail ripple cf SE designs .... just a hint

As always ..... have fun

cheers, mark
  Reply With Quote
Old 26th April 2002, 12:33 PM   #10
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Peter,

I am sure your new cap bank will sound better. Several audio manufacturers have replaced large electrolytics with many smaller ones. Lower ESR and better high frequency characteristics.
Your new cap bank looks good.

Jam

P.S. You must have a machine shop at home, you have got most of us jealous.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
paralleling film caps with electrolytic caps jarthel Power Supplies 386 23rd April 2013 09:09 PM
Does someone know these electrolytic caps? 12 Cents Parts 4 25th November 2005 09:26 AM
Electrolytic Caps jhead Parts 0 21st April 2004 10:11 PM
More Electrolytic Caps MRehorst Swap Meet 3 26th December 2002 10:56 PM
Electrolytic Caps MRehorst Swap Meet 5 12th December 2002 03:45 PM


New To Site? Need Help?

All times are GMT. The time now is 07:10 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2