Normal
Nothing can control the volume of a compressed bitstream (DTS/AC3/MPEG/WMA etc) without decoding it, so all Windows can do is mute it completely i.e. it's 100% or 0%. The slider is there because if the spdif stream is stereo PCM it *can* control that (like any other decoded audio). It's always better (from a quality perspective) to control volume with the amp - just set the windows/MP volume to 100% and forget about it.
Nothing can control the volume of a compressed bitstream (DTS/AC3/MPEG/WMA etc) without decoding it, so all Windows can do is mute it completely i.e. it's 100% or 0%. The slider is there because if the spdif stream is stereo PCM it *can* control that (like any other decoded audio).
It's always better (from a quality perspective) to control volume with the amp - just set the windows/MP volume to 100% and forget about it.
