Kent S. said:
Err, ... not quite the -10 is more for lower levels, semi-pro multi tracks and such, the +4 is for pro line level, and works best with preamp outputs, if the unit was put thru an amp's FX loop that was a send and return for pedal levels then -10 would be the way to go, pushing a preamp output into it, +4 would be the way to go ... also there is usually an impedance difference as well ... nothing to worry about, it just works out better on +4 for preamps and for line level outputs from mixers and what not. A good way to zero in you gain is to test your cleans, get it without clipping and then set you distortions to the same level ... most people wind up setting up their cleans a bit louder than their distortions because of the headroom difference, accounting for the greater peaks of the cleans, even though the distortions come out a bit louder sounding. If it works good clean, it will work good dirty.