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Re: 12A_7 local NFB?

1/27/2005 6:07 AM
kgRe: 12A_7 local NFB?
honestly, the big thing about the input stage is that a) it should be a tube! and b) it's singular purpose is to get the amplitude of the fragile guitar signal out of the "mud" of noise. imho at least.  
voltage gain per se isn't really the big goal... just enough to boost it to the level of 10s of volts. the input stage itself won't be likely to ever clip unless you run an active preamp on the guitar, or a stompbox.  
and--as always--make it as quiet as you possibly can. dc heaters, high gm tubes, low value resistors, high plate current, etc.  
fwiw, i've tried the 12a_7s, the ef86's, even el84s, cascoded solid state circuits... the one i've stuck with is a 6c45pi with an active plate load (current source).