VidaBlue2U

I have been using AE to distribute music wirelessly for sometime and overall am very happy with the results. I use the DAC in my Marantz SR 7001 receiver and today noticed while listening to an HDCD copy of Doc & Dawg that the HDCD indicator light is showing. If I switch to a non-HDCD selection, the light is no longer activated. It was my understanding that AE was limited to 16bit (itunes shows 16bit in info tab), am I really getting the 20bit version, or am I missing something? Thanks for your help!