Quote:Jeff Zhu's utilization of HDMI as a tethered source is opening up a whole new highten input as far as I can see. Four lines one for data stream and three for clocks! Another veil will be eliminated.
Yes, the I2S implementation sounds really good. Guessing all of it is!
I have heard quite good USB implementation, and with good cables
it can do less damage and sound pretty complete and musical. Interestingly, with more refined mains power, with my modified DAC having improved internal power, USB, clocking, etc... a special USB cable I made sounded more like music to me
without the jitter bug and Uptone USB regen combination I had used for a long time with other nice USB cables. I think this was a combination of progressive power, power cable, computer, and DAC upgrades,
and a better USB cable.
My DAC has separate transformers for the input and output/DAC boards, as well as two pretty heavy chassis "walls," isolating the transformer section and the input and output boards. To this, I added noise and vibration refinement by ear, along with improving the power supply, clocking, etc. No small part of this broader equation was from following some guys who know loads more about it than me. I first tried a homemade silver coax cable bypassing the connectors and replacing the cable between input board and the DAC chips on the output board. This was a big improvement over the stock copper coax setup. But then pulling the cable and installing a good Crystek clock and a little cap right next to the DAC chips, that made the DAC notably more resolving and musical.
When I got a Kitsune Singxer SU-1 USB Bridge, HDMI/I2S did prove to be more solid and complete, but I think this was a combination of the extra good USB cable I got lucky with, the well implemented USB Bridge,
and using I2S into the DAC. The Kitsune Singxer, with an improved power supply, connectors, good femto clocks, upgraded regulators, etc, does a lot to keep the digital stream clean while also refining the stream before the I2S. And even with this sophisticated USB "treatment," doing cable tests with some good USB cables, they still sounded different enough, computer to Singxer, to make clear sonic choices, and my hierarchal preferences remained the same as pre-Singxer.
Experiments also indicated the computer can be a big deal when everything gets refined enough to hear it. The streamer can mess things up with less than stellar parts, design, OS and player software and filtering schemes....and worse if these are resource demanding making the computer work harder, and creating noise and digital artifacts related to heat as well as too much processing and vibration. Seems this is why dedicated servers are using simple OSs, to avoid a hyper active OS doing non-music processing and contributing to digital issues. And I experienced this 1st hand putting a stripped down OS in my computer...the sound got notably more resolving, so much so I had to adjust my system for the added density. Associated, it seems that often more efficient parts tend to be quieter, while also processing digital better. I find that better hardware and setup alone, including not sharing the USB buss with external drives, can help keep issues lower in audible ways. If the digital hitting the USB cable can be sent with little need for "repair," seems undamaged digital, in most cases, has to be better than "repaired" digital.
Same with HDMI.... Working with a buddy on finding and/or creating the most transparent I2S cable, once again, we heard that digital is not just 1s and 0s, "digital" cables making about as much difference to the sound as cables on the "analog" side, between components.
As with USB cables sounding quite variable, some HDMI seemed to create less coloring and damage to the digital stream, and some truncated aspects of the stream and/or colored the sound. So though I2S is conceptually a better format technically, still HDMI cables really mattered in our tests. And like USB cables, it clearly depends on cable design and materials, but I find I just can't tell without listening tests. We tried lots of non-audiophile cables, a few sounding similar, but most were notably different sounding, both of us using good power and tuned up Minis for servers, his HDMI coming out of his unmodified Singxer SU1 and into his additionally modified Kitsune Holo Spring2 DAC, ....and mine using a tuned up Singxer, and a tuned up Gustard X20 Pro.
So I guess all this points to how fragile digital-to-analog can be, and ways to avoid doing damage to it. And if the digital stream is cleaner to start with, it is easier for the DAC to be more effective. I guess the May DAC takes care of a lot of this in its design, but it would be very interesting to look into how it does with considered attention to the digital before the DAC!
Anyway....so far, my experience says that a great DAC can be notably greater with care and attention to what we are sending to the DAC.