I would really appreciate if someone from Line6 and having understanding of the internal processes will answer this questions.
So basically I use Line6 POD HD Pro as an audio interface and FX loop. The chain is the following:
Bass -> Bass Amp -> XLR line out -> POD HD Pro XLR front mic in (-> optionally a few pedals in the FX loop of the POD, but we can skip them)
Evidently, my goal is to record with best signal/noise ratio and get no overdrive in the (pre-)amps, so I set to max possible gain on the bass head but keeping low enough not to produce any clipping. Then comes the bass head line out level and POD mic preamp level (I guess this is 'gain', not 'level') with additional posibility to do -20db using a small button near the XLR socket. I don't use this button, set the POD mic preamp level to min and rise the bass amp line out level again as high as possible such that I don't clip on mic input of POD.
And here comes the question. With all these settings the recorging level is relatively low. I need to say that it is not very low, it is normal, but I would expect getting at least to, say, -2 db or 0 db when I clip at mic input. Currently the fast attack of a note, which produces slight clipping in the mic preamp will be recorded at peak of approx, -8 db or such. Why should I waste dynamic range? Are there any knobs to turn and get the signal back, but not increase the volume after digitization either in hardware or software.