Aesthetix Calypso getting hot on the left side


I've just bought a used Aesthetix Calypso preamp and I'm very happy with its sound.
But I'm worried as it gets hot over the left side of it.
The source of the heat is on the left side of the common board, just on the left of the AC cable channel before it enter the transformers enclosure.
It's definitely hotter than on the right side, but not so hot that I couldn't place my hand on the cover over it.

Do you think this is normal?

Kiriakos
kiriak
@Mattkimb96
it sounds reassuring

@Zd542
I have the one with the yellow capacitors.

But the heat does not come from this board (with the tubes) but from the common board with the black smaller capacitors and the alone transistor that is between them, just on the left of the mains cable groove.

Many thanks to all of you!!
Have you contacted Aesthetix? That is what I would do instead of asking the question here.
I got this answer from Aesthetix

"...............
For the area that you mentioned, it is normal for it to get fairly warm.
..................".

This was a same day answer and thanks to them for the immediate response!