Jim, you want me to reply in this thread and I will do so.
Actually I just can stipulate, it is no DAC problem, as the DAC (which is a Devialet) works perfectly with JRiver under Windows and runs perfectly with itunes under MAC. But I'll get this sample rate issue with the JRiver MAC version 19. And I want to use the MAC version for several reasons!
And the second point: You suggested re-sampling to e.g. 96kHz for all files. Well, where are the disadvantages of this solution? Do we have any sound improvement or degradation?