It is well known that the 1/8 jacks on the MT2496 need a pad. There were lots of aftersale items available to allow 1/8->1/4 conversion. The problem does not exist with the 1/4 trs jacks. This is very different than the MT2 which seems to favor the 1/8 jacks. I have used the mt2496 since it first came out and I always just go through the 1/4 jacks. I do have a (1/8) 10db pad, but from MT, but have never messed with it. There is no clicking noise when using the 1/4 jacks as has been a problem on the MT2. Balanced or unbalanced does not seem to have any effect on the sound. the L/M/H will depend on your mics. For instance if I use my AT 853, I am usually on "L" and if I use my Church mics it is ususlly "M" or "H". These stand for Low Medium and High although some think it is line and mic and ??. It is not per the manual and hours of recording. I hope this helps!