How hot is hot when moving from class a/b to to a or tubes?


I am considering moving from a class a/b Luxman L509x to a class a or tube amp. 
I have never owned a class a or tube amp, so have no experience of living with one. My kids are hopefully old enough and wise enough not to burn themselves, but I do live in an already warm house with bifold doors leading to a south facing garden. There is no escaping the sun, despite having uv treated glass. 
 
My room is roughly 9 meters by 12 open planed living space. Equipment is, Luxman L-509x integrated, Zu union 6 supreme, 99db sensitivity (this is why I am considering a lower powered tube I can barely turn the Luxman up) music is played roughly 6 hours a day, more on weekends  

who here has moved from class a/b and d to class a with or without tubes. What were the differences of things like:

warming up time 

additional heat to the home

Running in summer time 

additional cost to run

any considerations I should make before purchasing something. I will try in my home, but will need to free up funds 
 

 

mpoll1

Showing 2 responses by jasonbourne52

There are very few true Class A transistor amps. Most so-called Class A amps switch over to Class B after a few watts. A true Class A amp of considerable power will always run extremely hot under zero load and then progressively cooler as output level increases!

A true Class A amp will always run hottest with no signal. When playing music the current/voltage goes to the speaker and is dissipated there. The true Class A amp then runs increasingly cooler! A little-known fact that most audiophiles are unaware of! My Bedini 25/25 fulfilled this design aspect as a true Class A amp. In use it always started out extremely hot and ran progressively cooler as output level was increased. Stopping playing music it again got hotter until it reached its bias limit.