For people worrying about hooking up speakers, most powered monitors (what most people would probably be using with this) have built-in power amps, but you don't usually control volume from them (controls are often on the back). This unit essentially functions as a preamp when used like this. If you do plan to use an external preamp, just set it to unity gain (90). Also, if it hasn't been mentioned, you can mute the line-out for use with headphones if you use the second headphone jack.