Is the problem end of life or the new processor?

Amps can last a very long time IF the power supply caps stay in good condition.  This is why you read so many questions here about getting amps recapped, and 20 years is about the minimum age these days.

If you do have them recapped, ask for high temperature variants.  They last longer.

I would agree @jeffbij ,  but these amps are beasts.   Shipping them is a pain.   Hard to find repair on this stuff, for me anyway.   My Classe went to NY, and when it broke twice I was done.  It was an SSP 800 however, and I am sure way less reliable than their amps.   I sold my CA2300 stereo amp after that, and new or used Audionet amps at any level sound better (to me).  There are many other good choices.

Thanks all for the replies. 

@fastfreight - yes they are beasts - getting almost too heavy for me to lift:). I also have an SSP-800 but it's boxed in the attic at this point. I went to Marsantz and just upgraded that to the Marantz Av-10.

@erik_squires - they have been on amp stands but you are right close to the floor. I periodically dust and also cover them when not in use but I'm sure there's an accumulation of material inside since they have been is use for 23 years.

@jeffbij - I'm going to have the amp looked at - Classe has responded (which I appreciate) by suggesting sending the amp as an out of warranty item to George Meyer in LA  or Deltronics in IL. 

I live near Boston so if anyone has a resource for amp evaluation I would be happy to hear it.

Thanks again everyone.

Sorry, can't help on a service resource in the Boston area, but I hope it works out well.  It would be a shame if they have to be retired due to repair/refurbish cost.

Let us know how it goes.