Hi,
I'm having a similar issue with an iFi nano iDSD BL.
DSD256 will only play if I use no DSD bitstreaming and set output encoding to 2xDSD in DoP, but that causes the app to crash pretty often.
I keep finding contradictory reports about whether Macs can output DSD256.
Where did you find your answer?
BTW I used the Conversion tool (Tools>Library Tools>Convert Format) to convert the files to DSD128 and I can play them using DSD bitstreaming. I figure given a few more years this will all sort out. Until it sounds pretty awesome.
Details:
15" MacBook Pro Retina Mid-2015 2.5 Ghz 16G RAM
Mojave 10.14
JRiver 24.0.53
Files: Truth, Liberty & Soul by Jaco Pastorius 11.28Mhh DSD256
When trying to play the files, using a) DSD bitstreaming and no output encoding or b) no bitstreaming and output encoding 4xDSD in DoP results in an error that DSD 11.2MHz cannot be started.
Using no bitstreaming and output encoding 2xDSD in DoP allows me to play the files, although it has a tendency to crash the app.
I then used the JRiver converter to convert the files to 5.6Mhz DSD128 files and they play fine using either a) DSD bitstreaming and no output encoding or b) no bitstreaming and 2xDSD in DoP.
Running Audio Midi Setup and selecting the ifi device shows a maximum 384khz.
Based on the Audio Midi Setup results, I would expect that DSD256 would require a setting for a rate > 700khz