Is the TEAC player running in the background? Maybe it's set to exclusive or direct modes that disables other programs from using it.
Problems with playing through DAC/headphones
Just bought a TEAC UD-501 DSD DAC and have been listening to lossless files via iTunes and DSD via the TEAC player. I am listening primarily through headphones, and the sound is great. For some reason, though, if I try to load a video via youtube or if I try to listen to music clip on an internet website, I hear nothing via the headphones. I have a MacBook Air and check the sound settings -- the TEAC is selected as the primary output, so I can't understand why I can hear music via iTunes and other dedicated players but not via my web browser. Any insight into this problem would be greatly appreciated! Thanks!