Room Nucleus One USB port out to fiber converter to Ethernet DAV?

I’m very confused about what your DAC takes as input.  If it’s older and has no USB input, or Ethernet input then you want to get a USB to S/PDIF adapter.   

In this case  you want something more like this.  The jitter is going to be at the mercy of the USB/S/PDIF clock though.  You lose the asynchronous feature USB audio is famous for. 

So lets back up a bit.  My suggestion for home network cleanliness is to keep power supplies away from your Hifi.  Either using a filter with known excellent noise rejection (like any series mode surge protector) or after market power supplies with very low noise. 

While fiber can help, I find the addition of 2 Ethernet/Fiber converters causes as many problems as they solve.  You now add 2 more noisy wall warts to your equation.  If you have a streamer with a built in fiber jack (i.e. SFP) that’s great, but otherwise you are just as well off with the use of an Ethernet isolator that’s rated to UL 60 601.  

Honestly though a better solution overall might be to do a Raspberry Pi end point from Roon and use an S/PDIF daughter board.  I believe that board has it’s own high quality clocks.  Not 100% sure though.   

@erik_squires thanks  

my DAC is integrated into my NAD M33.  It’s a pretty sophisticated DAC with the ESS 9028 Sabre DAC chip.  I do not have the NAD module which would allow for a USB streaming connection.  So the best hardwired connection is ethernet.  That’s what I use currently. 
I was just wondering if that USB/fiber converter that I referred to in my original post would work so I could see what the effect if any of connecting to the room through it’s USB port. I’d use the iFI power X to power the fiber to Ethernet converter that would feed the DAC   That (and the M33) would be connected to an AQ powerquest 505.  (The USB-fiber converter runs off the USB power, no additional power source needed.) the Roon nucleus, the router, cable modem and switch are all on a separate Furman PST-8. 

i’m pretty sure that the net effect of converting back to ethernet in the first place means I’m gonna lose the higher frequency and 32-bit depth that the USB port seems to offer, but  I’m still interested to see if it’s any improvement in sound quality or reduction and noise over what I’m doing now, (which I must say seems to have a very low noise floor). 

thanks! 

You are much better off using the Ethernet and Roon.   I'll be surprised if you can use the Nucleus USB port as, essentially, a USB network adapter port. It’s only there for music, and expects a USB music receiver.   

So, you could, as mentioned, use a USB to coax converter (though this is iffy due to hardware compatability issues.) and end up with S/PDIF, but that loses the asynchronous features.  

Using Roon over Ethernet allows the use of the M33’s asynchronous mode and internal buffer.   Having said that, you can use an isolator or even do Ethernet/fiber/Ethernet conversion if you want to which maintains the asynch features.

Asynch is important because it allows your DAC’s clock to be the single metronome used to reproduce music.  

As @erik_squires said - use M33 as roon end point. You don’t need to use nuckeus usb. Go to Settings, Audio and enable M33 as a device in roon