HDMI to Stereo Rca will it improve audio quality.

I have power dvd with realtek alc887 which is not supported in power dvd for high Def audio output. But I have radeon HD 6450 which hdmi outout, I don't use hdmi port for either video or audio out. Question is
If I'm using hdmi for audio out with hdmi to stereo adapter will I get better sound or full resolution sound.
For e. G like this Alcoa Prime Audio Extractor Converter HDMI to HDMI & Optical SPDIF+RCA L/R Audio Splitter C1:Amazon:Electronic