Pass XA 160 review:life span is 6 years?

Caps have a limited life/ performance expectancy. Change the caps & you're set for another 5-6 yrs.
The performance is usually spec'd in hours of operation. However in powering up/down, components do get a small beating...

"Gregm" is correct - the bus caps will have a finite life period
where leakage remains within their spec. All designers calculate the life
expectancy of the caps since these are virtually always the limiting
component in regards to life expectancy. Or, at least they should be doing
this and providing us with the info.

The Pass amp is no different than any other amp that uses electrolytic
capacitors, especially the bus rail caps. Be advised that the actual realized
life will be far greater than the calculated life since the calculations are
generally made using worse case parameters - such as the amp being run at
max watts, in the highest spec'd ambient temperature, etc.

Yep, change the caps and you're back in business - when you really need to
which could be a long time away. No reason at all to fret this as it is
generally a simple activity. If the designers of the other amps can't give you a
life expectancy then maybe you should shy away from their product since
they likely were not diligent in their design process. At this point I would
say the Pass is a very well designed amplifier.

I have one of those Monster Krells (Ksa-250), 20 years? Mine went in at 11 years. Krells response after rebuild:

It should sound better than new and last another 10 years or so.

None of the amps that run hot will last as long as cooler running amps under normal/heavy use. Of course there could always be reports of exceptions to the norm.

Dave

The XA series is class A which means they are always charged up. This probably means they are "used up" faster than other designs. But still, 50,000 hours is a long time!

Dave & Budrew pointed out an important issue, heat.

All Pass runs in high class A or full class A, class A means lots of heat and transistor is always on. Unlike your computer CPU which is based on CMOS, transistors used in power amp are either BJT or MOS and will draw current (and create heat) when they are on. Heat kills unless you have active cooling, but you don't see Pass amps with coolant running around or forced cold air into the amp. Therefore, you have transistor life expectancy on top of cap life.

Buy tubes, just replace the tubes and you are as good as new.