10. Direct Out jack - Use this electronically balanced XLR jack to route signal from the Model 3500 to a professional mixing console or as a tap to a main PA system via a mic input on the console. The signal output from this jack is low impedance (600 ohm) with an output level of approximately -30 to -20 dB. You can also use the Direct Out jack to route signal to an external amplifier with a -10 dB input sensitivity. when it says i can route a signal to an external amplifier, what kidna amp would it be? and would i need a special chord due to the different jack type?