Preventive maintenance or wait till it breaks?

Maintenance requirements vary according to environmental factors. Cigarette smoke is one of the worst fiends. That, along with high humidity and airborne dust create a layer of foul-smelling crud on everything. This wreaks havoc with convective cooling and throws finely tuned circuits out of tolerance. Every vintage piece of equipment I buy gets torn down, vacuumed, dusted with a small artist’s brush and cleaned of any flux residue etc... after that things look better, smell better and work better and longer. 

Buy Bryston, 20 year warenty that you raley even need to 

Bryston service is excellent. I've had an amp repaired- the turn around time was amazing. I also had a preamp refurbished- at no charge. 

My take on this is a little preventative work goes a long way... Take the top off and clean everything with a vacuum and acid brush plus blow it out with compressed air, why?? Heat is your enemy and thats what causes heat fatigue on caps and soldier joints (look for darkened spots on your PCB's.  If it's running primarily in class A, get a six inch (computer type) fan and cool it...