Hello,

I am an applications engineer with Benchmark Media Systems.  Jsa contacted me regarding this problem.  It seems that the 24-bit operation is what is preventing XXHighEnd from locking to the DAC1 USB through 'Exclusive Mode'.

Peter, operating at 24-bits has several advantages, even if the audio is 16-bits.  For instance, operating the software's volume control will result in a greater-than-16-bits digital audio stream (because the math leaves remainders).  To reduce to 16-bits, the data must be truncated (omitting all bits after the 16th) or dithered to 16-bits.  Truncating results in serious distortion, as you may be aware of.  Dithering is acceptable, however it requires extra processing.  If the result of the software volume control was left undithered at 24-bit, the distortion would be sufficiently below the performance of currently available D-to-A chips (i.e., < -150 dBFS).  In other words, it would not have any audible degredation. 

I understand you probably have a very full plate with regards to modifying your software.  And I commend you for this open forum for feedback...I wish all software designers were as open to suggestions as yourself!

Thanks,
Elias