This is quite interesting. I have being measuring with my limited home equipment, a Creative X-Fi SB0460 and a X-Fi front panel. The actual numbers are of course, not accurate at all. But as I am comparing this unit to what I got from a previous drop, i.e. a SMSL Sanskrit Pro-B DAC.
The results I am getting are saying that the Pro-B is performing better in terms of THD and THD+N from sine waves generated by ARTA in different frequencies ranging from 20 Hz all the way up to 11,000 Hz. With the SB0460 front panel as the SPDIF output @88.2Khz, both coaxial and optical, the Pro-B DAC managed to beat the M9 by around 0.001% of THD and THD+N in almost every frequency I measured. The two DACs are roughly performing the same when USB is used as the interface and the best result was achieved at setting both to @176.4Khz.
My guess: the clock of my SB0460 at 88.2Khz when used in combination with the Pro-B DAC resulted a smaller jitter than that the USB interface SMSL had implemented on both DACs.
Let me know what you guys think, or if anyone wants the data I've recorded, even though those numbers are not going to be accurate whatsoever.
Thanks for reading~~