In regards to your inquiry about the Amber 3's performance compared to the internal DAC in the Cambridge. The Amber 3 is in a league of its own, there is really no comparison to what you currently have. I had a PS Audio NuWave DSD DAC, which was a fine sounding unit, but absolutely NO comparison to the Amber.
I'm also a Vinyl guy who has four times the investment in my Vinyl set-up than the Amber, and I am floored by the DAC's presentation, it's very special. And, my only source to the DAC atm is an OPPO UDP-203 via Digital RCA Coax.
I guess it should be noted that the Digital RCA Coax inputs are limited to 24bit/96 kHz on SPDIF (which sounds remarkable) The highest resolution (up to 256 x DSD, up to 385 kHz PCM) output of the DAC is obtained via the USB input.
So, you must have a device that has a USB output to obtain the highest resolution play back. Your Bluesound 2i does not have a USB output. I'm picking up a Streamer/Server or a MacBook Pro to incorporate as a Server to stream Hi-res files via the USB input.