I also agree with most others here to keep the tubes visible. I remember Roger Modjeski of Music Reference once writing about his tube amp philosophy - keep the transformers in the back and the tubes in the front for better ventilation. And his amps have always been known for their long tube life....I personally hate it when tube manufacturers hide a portion or half of the tube into the chassis. I like to see the whole tube exposed. (not to be construed as a political statement, sexual preference, double entandre, or anything other than my preference on tube amp aestethics).
Manufacturers don't get it. make tubes visible.
After all of this time, why don't manufacturers get it? Everyone I talk to who owns tube gear wants to see, at the very least, the power tubes while the gear is operational. Many want to see the preamp tubes as well. So why do so many great manufacturers still bury the tubes inside of the gear? Are they afraid we will electrocute ourselves? And, if this is true, who is going to miss a few deranged audiophiles anyway, not to mention their wayward offspring and badly trained pets? Interestingly, large transmitting tubes which pose, by far, the greatest danger, are almost always out in the wind.