The line in is an analog input, so there is no way to bypass the internal preamp. You can use it as a digital input recorder, but that is only through the USB port. (stereo only) Be aware that the line in on this unit is sensitive, so you will most likely need to a.) reduce the gain on the 9100, or b.) get an inline 10dB attenuator. I suggest option( b.) M-audio sells one with 1/8" ins/outs for around $20 I thiink.