"I always thought the tone / distortion from Tube amps came from driving the inputs . . . not cranking the actual volume up."
actually, it's both............the idea is to layer the preamp tube distiotion with the powertube distiortion.
i can't imagine that you're able to get so much volume that you're distorting your mic. most tube amps are only 100 watts max.......i do believe there are some that are more, but not a whole lot.....so anyway........i'm assuming that you're using a 55, 60, or 100 watt amp.........i've been told by a guitar tech that the difference between the max. volume ona a 55 watt amp and a 100 watt amp is only 3db...........
the other day i was recording two amps at one time, and the other amp i was using was a really loud solid state amp, so I recorded my 55watt amp at like 8 and wasn't getting any distortion from my mic.......I can't imagine that you would have had it that loud......it doesn't need to be that loud to get the powertube distortion you need.
if you aren't able to get you're sound by haveing it on a lower setting than 8, maybe you're tricking your ears......
.i think i read in here that you're ears are flatest at about 80 or 85 db....but as the volume goes up, the amount of percieved low end also goes up......
i don't believe microphones act in the same way as your ears. i don't think volume effects their frequency response much. i may be wrong though, and now that i've thought about it, i think that i am.
but here's my theory.(based on the assumption that i'm right) ...... even with that loud volume, the amp isn't going to sound the way you want on the recording. to get the sound that you are hearing at the volume level you are recording at, all you would have to do is a mid scoop, or boost a little low end with EQ. and you could turn the volume down to a level that's not distorting your mic.........but i honestly think that either you have a faulty mic or something in your signal chain is distorting.
but like i said..........i may be wrong and i think that i actually am.
it would be nice if someone told me if i was right or wrong.