Optical vs Ultra Rendu.

classdstreamer - Yes, just learning. I am currently rebuilding my system. Have speakers and amp but no streamer at this point. 

Originally had a Macbook Air to DAC via USB then a Roon Nucleus to DAC via USB. I am debating between the two SGC unites mentioned in my initial post and trying to get a feel from others on their related experiences.

I'm sorry, I must have missed your link, I'll go back and check it out, thank you.

classdstreamer - OK, I read the PS Audio article. Still not sure which way to go. I'll keep researching, thx.

I have my Server Pink faun 2.16X hookup to the router by fiber since a few time by a multimode fibre and convertors in witch end. But now I made an upgrade using a singlemode fibre hookup directly to the server via a NIC (network interface card) with modules SFP+ for 10G power supplied by an inside server carrier of LPS. On the other end i hookup the router and the converter power supplied  by a farad LPS (with super capacitors) and between the router and the converter a Cooper RJ45 cat.6 (Shielded twisted pair cable (STP) ) of 15cm to does't infected easily by EMI and RFI. What I can say is that I can't be able to distinguish the music files from the streaming, the SQ of the streaming is amazing. Next think to do is swap the router with one with a 10G out of internet, that it seems came to the market for the next year, and with it all the network path will be isolated from noise. About the jitter on fibre I don't worry about it because the server has a Pink Faun ultra OXCO that eliminate the jitter that can exist.

Previously  had Switchs, like EtherRegen with a external clock, a filter ENO and even the SOTM snh-10G W/CLK for a month. They offer a sound clean but artificial. I came on the conclusion that nothing better than to treat the problem on the origen and the sound it will be cleaner and natural. 

So, as an update, I gave up trying to avoid Chi-Fi and bought a Denafrips Pontus II DAC. This has an I2S over HDMI that is compatible with the I2S output of the UltraDigital. Although I could just use USB from the UR into the DAC, this way I can use the UD ( I did pay for it!), and some feel the I2S sounds better than USB. Of course, USB is still in use from the UR to the UD. As the system has broken in, things have improved steadily, to the point where things sound really good. I would still like a little more warmth and smoothness, but maybe that will come with more break in. I also put a small dip at 3kHz in the digital chain by using the Roon DSP. This seems to help a lot without messing anything up.

Meanwhile, after speaking with Andrew at SGC, I am considering the fiber optical converter bundle, for $350. It is returnable if it doesn’t provide any improvement. I have to wait for funds for this purchase to be available, but I will try to post here if I get this bundle.