Class A amplifiers

I have Salk Sound speakers

im thinking of buying a mark levinson 50 watt class a amp except I’ve never bought used gear and am a little gun shy . Lol

A well built Class A amp might need servicing every 30 years or so...but so will all the non Class A amps - they need the electrolytic capacitors renewed.

Last week, I shipped my Krell Evo 402e for a factory refurbishment. It is played six to eight hours daily for 10 years and well ventilated. I plan to keep it forever and feel it a good investment to refresh the unit. 

I have Plinius SA 102 in dual mono at 125 watt pure class A stereo and 740 watts mono.
Bought new in 2004. Still running great!
Also Plinius SA 100 mk3 runs fine.
Also a Cary 300b sei 8 watts pure class A tube amp running great. And ...
A Dared VP 845 18 watt pure class A running great.
All amplifiers need proper care and ventilation.
Follow those simple requirements and they will last forever.
What is needed is a little care and common sense. Know what speakers perform best woth a given amplifier.

I have a Spectral DMA 200 that sounds wonderful driving a pair of Magnepan 1.6's. I have tinnitus so I can't hear the cooling fan. And yes, it helps keep the room warm in winter. Not bad for a 34 year old amplifier!