Playing flac files on my Mac book


I want to use my Mac book as a music server to take advantage of the spdif to optical input on my dac. 

I transfered all my flac files to the mac into a folder. I have tried VLC and Windows Media but the sound quality is very poor and highly distorted sounding.

I have gone to quite a bit of effort and expense to update this Mac but am very dissapointed. 

Where have I gone wrong. 

Thanks for any help you can offer. 
128x128pkvintage
I should add. This Macbook does have the spdif/optical shown in the list of outputs. Thanks
Probably the best source of help for problems using VLC on a Mac to play FLAC files would be in the support area of VLC's developer.
https://www.videolan.org/support/
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