DDC Sound Improvements???

I can share some generalized thoughts based on my experiences owning the Hermes and the Singxer SU-6 (currently), and with streaming Tidal, Qobuz, and stored files using Roon in my system:

• Assuming the server is powerful enough to competently process Roon Core, I have not heard any sonic differences between servers.
• Streamers (aka. Roon endpoints) have resulted in a more significant impact on the sound of my systems.
• A DDC provides isolation, reclocking, and format conversion (e.g., multiple outputs), but since a competent DAC also provides isolation, so the better the streamer and DAC, the less influence a DDC should have on the sound of an audio system to the point where the user may not "hear" a recognizable difference in the sound of their system when using a DDC.
• One benefit a DDC does provide is that, in converting the streamer’s digital output format so that multiple formats can be selected, the DAC’s optimal digital input format may be used.
• I2S may work fine with some components but, in general, is over-rated as a connection protocol between two audio components and is not likely to significantly change the overall sonic presentation of most DACs compared to an optimized S/PDIF or USB connection (IME). 

@whart,

I don’t think of your inexpensive digital system as ’cheap’ at all. I think of it as money smartly and wisely spent. That Shanling ET3 CD Transport is a model of compact design, loaded with surprisingly high tech hardware and software at a modest price inputting external SSD via the USB.

Same with the Gustard U18 DDC, and the I2s cable into a Gustard X26 Pro. To me, that’s a lot of bang for your buck.

I’m surprised you haven’t upgrade to a (used maybe?) Gustard U26 DDC (or even the GUSTARD S26 AMD Ryzen 5 5600U Music Server) and a Gustard X26 Pro III while upgrading the USB, I2s connectors as well, if you’ve not done so already. 

I use a cheap digital front end- a I use a cheap digital front end- a Shanling ET3, as a file transport from an SSD outputting via USB. I installed the earlier Gustard (U-18 DDC) to run I2s into a Gustard X 26 Pro, as a file transport from an SSD outputting via USB. I installed the earlier Gustard (U-18 DDC) to run I2s into a Gustard X 26 Pro

Thanks, @Tyray-- I'm not really chasing absolutes with the digital front end- my mainstay is vinyl and older, often more obscure pressings. I do enjoy the digital stuff though, far more than in the past,  and am pretty satisfied with that front end for modest cost. 

Good listening!

Same here, I’m in the process of upgrading (tricking out) my Technics SL-100C turntable.

@mitch2 ’s comments below are an excellent summary -- pretty much all one needs to know on the subject