Check in: How quickly are streamers and servers evolving?

I just finished doing some testing with 3 streaming solutions I have in my office system.

STREAMERS
- microRendu with linear power supply (LPS) 
- opticalRendu  with linear power supply (LPS) (I have 2 of these)
- RJ45 streaming with 1 DAC 

DACS
- Benchmark DAC3B
- AudioMirror Tubadour III SE DAC
- KRELL K-300i integrated amp with internal DAC

My RJ45 streaming was to the internal DAC of my KRELL K-300i integrated (latest model). My network switch is a brand new $199 Ubiquiti Networks switch that has both RJ45 and 2 Fibre slots. I am using regular CAT5 Ethernet cable into the RJ45. The USB cables I used were either free from Benchmark or $25 from Schiit Audio. I am buying a $200 USB from WyWires that has not been shipped yet. I plan on using that one with the winner of this test. A fibre wire goes from the network switch to my opticalRendu and then by USB to one of the 3 DACs. My source of the streaming is a ROON Core on a very cheap server in another room. The musical bits (1's and 0's)  need to travel by PowerLine copper to my office. I use ROON client on cheap computer or iPhone.

For some reason I settled on Fleetwood Mac's Dreams from Rumors as the song I would compare with all the streaming types. There is a lot of percussion hits on this song that are a bit hot sounding but it was interesting to compare this with the 3 streamers.

The RJ45 and the microRendu were about the same on the KRELL. The percussion hits were noticeable and the music sounded good. 

I then flipped the USB cable from the microRendu to an opticalRendu and compared with the RJ45. A massive difference in sound and also volume. I did not need to compare any minor details. There was more of everything with the opticalRendu. The percussion hits seemed like they were happening in my room, so realistic. I also compared the microRendu and the opticalRendu on the KRELL and the same results as the RJ45 and the opticalRendu.

I then compared microRendu vs opticalRendu with a Benchmark DAC3B and also a Audio Mirror Tubadour III SE DAC (tube). In both instances the optical had a massive improvement in sound. I am going to be selling this microRendu and LPS now.

This test for me was to prove to myself whether fibre is really today's holy grail for streaming. I think it is. I do not plan on testing with a dedicated music server (instead of a cheap computer as my ROON Core). I just think the fibre functions as an expensive music server in that it lowers the noise on the network.

@audio2design I was also very surprised that the volume seemed louder. I did not get out my iPhone DB meter to measure but subjectively I thought it was a bit louder. The fact that it was much better was without a doubt.

I am using the ROON ONLY version of the opticalRendu. I have no need for any other protocol other than RAAT. 

I should have added that when I listened to my setup with my Thiel CS3.7 speakers I used DSP Convolution files running on my ROON Core. Those DSP'ed bits were changed before they hit the DACs. On my RAAL SR1a headphones I have now removed all digital adjustments. In the past, had  bit of a bass boost using the ROON ParametricEQ settings but I have now removed that for the opticalRendu.

It would be so convenient if DAC's had a fibre input like the Lumin X1. Then I would not need an OpticalRendu.

I see the Benchmark DAC3B mentioned above. I have come to the realization that this DAC is a phenomenal performer. It is neutral but amazingly fatigue free for me. My AMT3SE is also fatigue free but that uses a tube. 

The DAC3B is also useful that I can use RCA and XLR outputs at the same time. I cannot do this with the AMT3SE. Vlad the designer, told me it may not work and my test confirmed that there is a problem using both outputs. Likely not an issue for most, but it would have been very useful for me.