C20 power transformer temperature

[cspyon]

Hi
Please look at the comparison of the temperature of two C20 power transformers:
The first one reads 126F after 5 hrs of running.
(This one is an original C20 in good working condition.)
The second one reads 127F after 3 hrs of running.
(This one has been fully restored by Audio Classics.)
I've also checked the temperature of their power supply caps on the top of the chassis, but it runs a bit hotter on the one restored by AC.
In fact, I expected the temperature of the original one would be much higher than the other one, but it wasn't. Any observation or comment?

 

[ramjet]

Why did you expect the original to "be much higher than the other one"?

 

[cspyon]

Why did you expect the original to "be much higher than the other one"?

Well, one is a rebuilt C20 with a well-regulated power transformer, and the other one is an original whose caps need to be replaced despite its good functioning.
So I just thought the temperature of the original one's transformer would be higher, affected by the old caps, especially the power supply caps...

 

[ramjet]

Electrolytic capacitors, particularly those in low current applications, as in the C20, will exhibit low ESR and remain withing their capacitance value range for decades.............right up to the moment they don't. It is that moment when their failure can damage that which costs much more money than their preemptive replacement (including labor and shipping) would. Hence my (and others) constant nagging to replace them.
The difference in current draw between the tubes in one C20 vs the other is probably a bigger factor at this point. Use the restored one and send the other one to me and think of it no more............

 

[cspyon]

Electrolytic capacitors, particularly those in low current applications, as in the C20, will exhibit low ESR and remain...

Nice observation, and I'm going to have it checked and recapped sooner or later.