8.14 Line Mixer Doesn� Work When Using FIREstation As t Stand-Alone A-D When using the FIREstation as an Analog to Digital (A-D) converter, the line mixer does not contain the analog signal. 8.15 The EXT Button Is Blinking The External If the EXT clock button blinks then no clock is present for the FIREstation to be slaved to. 8.16 The Sample Rate LED Is Blinking If the LED for Sample rate/external device blinks, then signal is out of the sampling range. 8.17 S/PDIF Feedback Loop If you connect the S/PDIF input to the S/PDIF output you will create a feedback loop. In other words you will hear some strange stuff.