[Amps] Horizontal or verticle?

[Richard]

There is a bit of debate between Polish and Ukrainian amp builders.

The some members of the Polish school argue, based on some American literature, that a valve (ceramic) should be based vertically, while some well known Ukrainian builders, have there GU74b's amps horizontal.

Now some Poles maintian horizontal is bad as, as for lack of a better word, "pollutants" which occasionally fall from the anode land on th grid, rahter than at the base of the valve as would be the case if the valve was verticle, and this eventually causes a short in the valve.

My feeling is that rather the cooling problem is the issue here, but I wonder s the valves were designed with the though in mind of working in any positon.

Any comments

Rgds

Richard 
SO5GB