jKeenan wrote:I notice that this transformer is hot to the touch while operating.
It is a hot August day in Florida and I don't need the extra heat.
The original Dynaco PA774 ran a lot hotter...there was almost 50% more
DC resistance on the secondary!
One thing I would suggest is to check the voltage across the cathode
resistor, do a little ohms law calculation and see how much current those
EL84's are actually pulling. If it's close to or more than what the
transformer's rated for (180 ma), I'd think about either raising the
cathode bias resistor value or getting a set of EL84's that don't run as hot.
If any transformer is run to where there's enough load for it to
regulate well (you don't want it run nearly unloaded), it'll
get warm, at least.
Some old TV power transformers actually had heatsinks
on the endbells...no room for that on an ST35, though..