External DAC for Cambridge CXN (V2) and Sony XA 5400 ES


The Sony was Stereophile A+ rated in 2014 which is probably prehistoric in digital years although still wonderful, especially on Redbook.  The Cambridge is excellent too although if I rated the Sony @ 100 the Cambridge would be 97 with extremely slight detail differences and a background that's just not quite as black.
I'm wondering if a nice external DAC would give me a detail and depth of stage boost?  I'm considering a Benchmark DAC 3 b to feed my Audio Research vintage (tube) pre-amp although Mytek (Liberty and Chord (Qutest) seem to have highly rated offerings.  Benchmark has a 30 day trial offer that might work as I'm well past the point of buying anything I can't hear in my room.. I'm leaning towards the Benchmark for the trial offer and I don't need a volume control since the AR pre has a remote volume.
Opinions?
midareff1
You will be surprised at how competitive the Cambridge sounds especially if you are routing everything through a vintage tube pre. I have compared the CXN to a schiit Iggy running them both into a Primaluna tube preamp and the difference between the 2 was surprisingly subtle. I really feel that DACs in the $1.5-3.5K range pose the worst value in the market right now because there are many DACs well under $1K that come very close to matching their performance and when you then run everything through a tube preamp with a pronounced sound signature / coloration, those minor differences between the DACs become almost irrelevant.
I had the Benchmark DAC 3 in my system for a few weeks on loan (running into a Mastersound tube amp). I have  CXN transport and CXN V2, and when running either into the DAC3 I found that although the DAC3 offered a very slight increase in detail, the stage was very 2D and somewhat boring. Probably technically more linear, but just not engaging to me in my 2 channel system. I really enjoyed the Benchmark with my headphone rig, but it just didn't do it for me in the main system. 

Another option you may want to look into is the Modwright upgrade for the CXN. Very few real world reviews so far, but it looks very interesting in my opinion. 
I have the Sony in my 2 channel system.  It is a refugee from a HT system when I had added an Oppo 203 to replace both my BluRay and SACD player.  In the 2 channel system my DAC is a Bryston DAC3, which has 4 HDMI inputs.  The Sony outputs the DSD from SACD over HDMI.  In the same system I already have an Oppo 105 outputting DSD from SACD into another HDMI input on the DAC, I added the Sony just for laughs.  It sounds almost indistinguishable from the Oppo as a DSD transport.  My recommendation would be get a DAC with HDMI
inputs so that you can enjoy DSD from your SACDs, if you have any.  I also think the Bryston is a better DAC than Benchmark