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How will I know when a Krell KSA-80b needs to be recapped?

How will I know when a Krell KSA-80b needs to be recapped?
cocopah
minorl
740 posts
 

You know when you "need" to recap the amp when:

1.  The caps failed and the amp doesn't work anymore.

2.  The caps show signs of imminent failure.  i.e. bulging capacitors, or sound quality is failing as a result of failing caps.

These are the only time one "needs" to recap the amp.

Any other cases are speculative theory.  If the amp is working, and there is no sign of imminent failure, then you don't "need" to do anything but sit and listen and enjoy.

Preventive maintenance is a good thing, but not absolute in this case.  You can budget for the cap replacement and do so at your leisure.  Or, listen for ten more years with no issues.

A lot depends on how hard the amp was driven (used) in the past. 

I would just enjoy

dhite71
17 posts
 
I don't know from personal experience, but I visited a quite reputable hi-fi repair shop in Nashville, TN and they said don't ever recap until they are physically leaking.  

ei001h
67 posts
 
Recently bought a 20 year old krell KAV500, worked fine for couple weeks, now I hear popping sounds from the amp while it's on and even after it's been off for several hours. It works well otherwise, full power to all 5 channels. Sound lasts less than a second and I hear them about once an hour. I was told the unit was recapped priror to purchase. Is this a cause for concern ? 
lowrollinghills
5 posts
 
A technician and/or factory trained person will bench test the unit
and check to see if the unit falls with in the factory spec.  If it fails to reach the numbers, then recapping and replacement diodes... etc will be called for.  
All companies will bench test wether it's off the assembly line or
in for an upgrade.  This is just standard quality control.  If your Krells
sound fine to you then why spend the money on new caps that will have
to go through the break in period?
(thats if you can still get the same components)
cjmc8
8 posts
 
The hotter an amp runs the faster the caps will deteriorate. If you have owned it since new you can guess how many hours are on it. If not things like heat-sinks turning from black to purple or even lighter would show lots of hot hours. A tech can look at the ripple on the caps and see approximately what shape they are in. Personally I would not like caps leaking in my classic Krell ever. I would have it looked at if you are unsure of condition.

Don S
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