Why so many tubes?


Many of the most expensive tube amps/preamp have multiple tubes...6, 8, 10. If direct path is preferred in the speaker by most, why the acceptance of a glass army in one's amp/preamp? 
jpwarren58
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unless you are the legendary Roger Modjeski ( RIP ) with oh so magical RM-10
More expensive preamps may use different tube configurations like cascode, paralleled, constant current sources, regulation etc.