I appreciate the two replies I have received on this matter. I understand the "scientific method" value of forcing the Output Format to a lower resolution to see the results. I consider this a last resort action because I value the Hi-Rez files' fidelity. I suspect it would work because, as I said, mp3 files play with no problems. I use dBpoweramp to rip CDs. I save to .mp3 files with the settings at Constant Bitrate at 320kbps to user/music/iTunes/media/music, which I use for my iPod Classic. I don't use the iTunes Media Player except to update my iPod.
The CD files I listen to at home through JRiver MC 22.0.97 are ripped to flac files at Lossless Level 3. I have tried ripping to uncompressed wav files and even converting 24/192 downloaded files to .wav so that my computer didn't have to uncompress the files for playback, thinking this might solve my interruption/buffering problem; but no luck.
Under the Tools>Options>Audio Device menu for my JRiver MC version 22.0.97, the device I selected is: "MF USB 192 ASIO Driver [ASIO]" where "MF" is the Musical Fidelty V-Link 192 DAC I am using. On "Device Settings" I have the Buffering setting at 500 milliseconds (the max) and a checkmark on "Use large hardware buffers (recommended to prevent stutter)".
I do have other choices under the "Audio Device" dropdown selection for the MF USB 192 Driver. They are shown as: "Musical Fidelity V-Link 192 Audio [WASPI]", then under the "More" sub-dropdown there are these choices: "V-Link 192 Audio 2.0 Output [Kernel Streaming]" and ""Musical Fidelity V-Link 192 Audio [Direct Sound]". I had read somewhere that my current choice (ASIO) is the best choice for the best fidelity, so that's why I chose it. Maybe a tech-savvy audiophile could suggest a driver that would work better (i.e. not stopping & buffering) while retaining full fidelity playback.
My equipment is an HP Pavilion HPE h8-1256s Desktop PC, Intel Core i5-2400 CPU quad core @3.1 GHz with 8 GB RAM running Windows 10 Pro 64 bit with all current updates. Playback is via one of the two high speed USB ports on the top of the PC, from a Western Digital 1 TB internal drive model WDC WD10EACS-00D681 designated as drive:E, through the aforementioned Musical Fidelity V-Link 192 USB DAC and into the Coax input of a Denon AVR-2310CI receiver. The motherboard sound card's digital output is not capable of outputting a 24/192 signal, which is why I bought the outboard DAC. The receiver displays "24/192" when playback begins, so this is confirmation that it is receiving a hi-rez signal from the outboard DAC. The computers Performance monitor tab in Task Manager indicates low processor usage and memory usage is at 2.6%; this with "Memory Playback: Load decoded files into memory" selected in Options>Settings. I did move the DAC's USB source from a rear motherboard socket to one of the two on top, which are designated as being high-speed ports. No luck, still stops and buffers. I think the playback driver choice may be the solution, but I don't know which would be the next best choice "below" ASIO.
Thanks again for your consideration and your thoughts on this problem!