2. amps-preamps
  3. 130661-70602

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
kalali's avatar
kalali
1,645 posts
 
This may or may not apply to the Krells but I was told a sign of electrolytics reaching the end of life is you can hear the capacitors make a faint sound when the amplifier is turned off. My old Adcom does that. The noise lasts only a second or so and it’s hard to describe but it is audible if you listen carefully. It almost sounds like you can hear the capacitors discharging. Just something i had read when a similar question was asked in the Adcom circles.
czarivey
4,494 posts
 

25...30 years, you don't need to really know when to recap. if it works, than you can decide weather you like the performance or not.

regardless, recapping old amp will have similar effect of the new strings on guitar -- fresh and crispy sound. also i would replace output transistors as they also tend to become noisy within same period of time.

randy-11
1,913 posts
 
https://en.wikipedia.org/wiki/Capacitor_plague
czarivey
4,494 posts
 
randy-11, it's when capacitors are completely shot. less likely the amp would power up or powering up this amp is unwanted.
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

More to discover