hi, i'm getting ready to retube my 400 plus. i've heard that i can get a better tone than the stock tubes. any suggestions? also, do i need to change out the preamp tubes at the same time?
I will be retubing mine soon too. Please anyone with thoughts on the 400+ specifically tell us. The M-B manual says to use ONLY M-B tubes because they're the ONLY tubes that are biased properly. Is this true?
Hmmm, Yes and no really. Mesa tubes are supposed to be matched for the same bias current(s). So in theory if you buy 4 or so of them with the same bias numbering you shouldn't need to do anything else but fit them in the sockets. You DO NOT need to do this with pre amp tubes only outputs. BUT there is no reason why you shouldn't get any other make of tube just as long as the supplier can give you "dual matched" sets (matched for gain and bias current). Try JJ TESLA's - they are brilliant tubes.