Audio Research VS110 Middle transformer gets very hot the 2 sides not so is this normal


After about 1 hour of play the middle transformers gets very hot  you can touch it but bearley 
the 2 side transformers nearly warm .
my question are 
is this normal or an issue in the making?
Is it safe to keep it on for 4 hours or not ?

Thanks for your advice 

molocka12

Showing 1 response by jwm

I was told a long time ago that if the power transformer gets hot but the other transformers remain cool then it's a good tube amp design.