When and why would you want a signal higher than 4 or 5 volt preouts? For instance my pioneer head unit has 4v preouts, and I know signal strength is important so I was thinking about buying an audiocontrol overdrive to boost signal strength but would it even be noticeable? As far as sound quality or output goes? When is a good time to get something like this? All I'm running atm is head unit, and an amped front stage.