Help an old guy with connection question please

Purchasing my first digital streamer (Bluesound Node2i) and would like to know how to connect to my Musical Fidelity A5.5 integrated for best sound.  MF has a built-in USB dac with a USB B input.  The only other inputs on the amp are RCA.  Please have mercy on an old guy with old gear for not being well-versed with the new tech.  I think it’s possible to go digi coax (out of Node 2i) to USB B but not sure that’s the best option. The dac on the MF may not be as good as the Bluesound so maybe better to just use RCA.  What say ye collective wise folks?
I use a Bluesound node 2 with a Kinki ex M1, an integrated amp. The Bluesound DAC is very good. Simply use an rca output from the Bluesound to an analog input on your integrated. You’ll be delighted.
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I have only analog inputs. 
RCA out of streamer to RCA in on integrated amp.
The OP's amp only has analog or usb digital.  
I doubt the USB input will sound as good as using the Bluesound DAC into an analog input. 
Unfortunately the USB input on your amp is meant for USB style digital data - generally from a computer

It will not be compatible with the digital output from the Node 2 - they are two different formats and probably differing digital resolutions

You will require some other device to convert the digital signal out from the Node 2 into  a USB style data stream.

Take a look at this Agon thread - it explains some related issues

The DAC in the Node 2 is extremely good and so are its associated analogue circuits. I have found that it performs to a whole new level of sound quality if you use great Analogue Interconnects and a great power cable.

Regards - Steve