I usually listen to one of the three radios:
http://quasar.shoutca.st:8468/stream
http://s7.iqstreaming.com:8014/live.ogg
http://icy1.abacast.com:80/kplu-jazz24aac-64
I have a strong, stable internet link and neither one of them *ever* drops out. But, *every* time the external thunderbolt drive spins up for regular Time Machine backup, the internet radio starts to stutter catastrophically. Even after the backup is complete, the stuttering continues indefinitely. After I stop (*NOT* pause, but *STOP*) the playback and then start it again, it continues ok (unless the backup is still running).
It might have something to do with the fact that the computer is networked through an Apple 27" Thunderbolt Display, i.e. through its ethernet interface, so all the network, and all the external HDD traffic run through the same thunderbolt interface. The TB throughput is way higher than the total sum of all bandwidths in question (max. theoretical speed of external HDD and the bandwidth of my internet connection) so it shouldn't be a bottleneck, but...
I'm not sure when the problems started. Maybe it was when I got the thunderbolt 2 external HDD dock instead of previously used USB2.0 external HDD housing. But I think not. I think it worked OK for some time after this change and the problems started with on of the latest VLC updates.
The setup is:
MacBook Pro Mid 2012, non-retina, 16 GB RAM, 480 GB SanDisk SSD
Apple 27" Thunderbolt Display
OWC Dual Drive Dock TB2 + USB3
WD Black 1.0TB external HDD
Mac OS 10.11.6
VLC 2.2.6 Umbrella (Intel 64bit)
(probably not relevant - Apple wired keyboard attached to the TB Display USB port, and Apple wired mouse attached to the keyboard USB port)