He He...... sorry 'bout the thread title but all will become apparent.... I've been rebuilding a Selmer all Tube head. It's been comletely refurbed new (Modern!) audio grade caps, ofc wiring etc etc. It's running 4 JJ E34l's - these are basically KT77's in a strengthened EL34 envelope. It's putting out around 120 - 140 watts. The biasing is set pretty "hot" on these tubes and they run (temperature wise) a fair bit warmer than the originals. Soooo ..... to help with longer tube life I have a couple of really nice fans (from a Sun Computer power supply). Question is: Do you A) "Suck" the cooling air over the tubes and exhaust it out of the cab? or B) "Blow" the cooling air onto the tubes from the outside as it were? Simple question but one that has me really confused - I think the answer is "suck" but I'm not sure!