Trying to understand why I hear a difference between USB vs spdif and AES inputs. I compared a vintage tube dac with a current solid state dac. I have a Levinson 31.5 reference transport. I connect it to a Sonic Frontiers MkII DAC via optical SPDIF or a Schitt Modius dac via AES.... I can't say there is much of a difference between the two dacs and the differences are subtle. Relevant to this thread... I never developed a preference between comparing the optical and coax connections on the SF and had no preference comparing the Coax and AES inputs on the Schitt Dac.
What surprised me was the difference between streaming a flac file of a cd to the USB input of the Schitt versus the cd played on the transport via AES to the DAC. I can't say one is better then the other... they are just different. The transport to the Schitt (or SFdac) is a bit more velvety sound quality while the USB is a bit more crystalline. Why such a difference?....
I can imagine a parade of reasons...and none make a lot of sense to me since I can't say the USB sound is good or bad.... just different...and I have no basis to understand the differences. So.... explanations like Jitter from the transport to Dac. Noise from the PC polluting the USB DAC or jitter in the USB interface etc etc are all theoretical to me and make no sense. Thoughts would be appreciated!
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