After retube transformer runs cool. Normal?

Tubes Asylum

Questions about tubes and gear that glows. FAQ

My amp is a KT88 based integrated which uses 4 tubes in the final in a push-pull-pull configuration. Since I have owned it the power transformer has always run hot to the touch after several hours of use. Hot that you would not want to leave your hand on it for more than 10 seconds. Will not burn you but too hot to want to hold onto for any length of time.
After searching the forum here I was led to believe this is normal and not to worry.
Today I switched out the four output tubes from EHKT88 to a new set of JJKT88. For whatever reason the transformer now is running cool in comparison, a very noticeable difference.
Is this the nature of the beast in that differing tubes can have that much of an impact on heat generated?
The amp is self biasing if this shed any light on the question.
If this is to be expected they Iâ€™m a happy camper since the JJâ€™s sound one heck of a lot better (more low end slam).
Thanks for any insight.
sdz

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Topic - After retube transformer runs cool. Normal? - seadzz 03:20:44 10/04/04 (5)

Is this set up so you can bias the tubes? . . - John PA 05:34:46 10/04/04 (0)

Your new tubes have a different bias point - Chris O 05:32:53 10/04/04 (3)

Amp is self biasing - seadzz 06:17:49 10/04/04 (2)

Re: Amp is self biasing - truep 07:05:35 10/04/04 (1)

Many thanks, that's what I needed to know. (nt) - seadzz 16:15:46 10/04/04 (0)

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