The device is/was correct: Mytek_Firewire
I'm trying to play ISO DSD, PCM 192., PCM 44.1
The Mytek works perfectly with others sw.
There must be a setting somewhere to change: JRiver? MIDIsetup? MacOSX preferences?
Add:
I've inserted on the path, in order to use as second device, an USB->S/PDIF interface.
PCM 44.1 & 192 play (I don't like the sound but it is off topic in this 3ad).
About DSD, I have this warning: "Playback could not be started on the output Core Audio using the format 352.8kHz 64Bit 2ch"