I am talking to a guy about building me an amp and we've been talking about an 18 watt all tube amp, woudl that be able to comfortably get over top of a drummer?
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BC Rich BW-4000BB
Schecter C-1 Classic
Depends on the drummer, the style of music, and clean headroom you want.

For a straight up drive channel for a blues/jazz drummer, it will be loud enough. With a metal drummer, it has the potential to not be loud enough, although I highly doubt it would be a metal amp :p. As Kyle and forsaken said, your clean headroom might suffer.
Major of 7 String Legion 7 > 6

Carvin DC747
Ibanez RG2228
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