alesis, я написал в службу потдержки лайн 6.ком и вот что они ответили
If you are connecting a preamp *within* the effects loop of the POD X3 Live, there is a very good chance that you will experience added noise and hissing.
?
The reason is... the POD X3 live effects loop operates at "line level" signal strength. Most preamps are designed to boost "instrument level" signals, which is much lower than line level signal. So you're basically feeding a preamp signal with a much higher level signal. Imagine sending a modelled amp sound at higher signal level than a guitar's pickup output signal through *another* preamp stage which is designed to boost/amplify a pickup output signal... this equates to more noise and hiss to the human ear.
кароч по русски: "Идите вы со своими проблемами в .опу!"