I don't have the Tchaikovsky's Suite No. 3 , but I have Debussy La Mer - Nocturnes from the same series and just confirmed I could rip it with foobar2k and then convert it to flac with AudioMuxer. I used the File/Open CD/Rip menu with Output Format = WAV in foobar2k to do the rip and then the Tools/Audio Conversion/Select Audio menu in AudioMuxer. I do have the ArcSoft DTS decoder installed in AudioMuxer; so maybe that makes a difference. When the WAV files are loaded in the Audio Conversion tool, it will recognize them as DTS WAV files if all is working. Here is a screen shot:
In the past, I have tried both of these, albeit without using foobar for ripping, and both failed. I admit that I am a completely unsophisticated user of AudioMuxer. I will try these again, just for the experience.As you have JRiver just drag the wav file into that and convert to flac. I've done that with all my DTS discs so I can play them via Roon. Should retain all channels doing this.