Esoteric PO3 Transport XLR Output

Agreed @georgehifi provided you can live with 16/44.1 you are set. 

My personal experience with my dCS stack is that dual AES/EBU is the way to go if you can manage it -- much superior to the prior best connection dCS offered which was via FireWire. The rough stacking order (assume we're transmitting 16/44.1 only) in my experience is
- Worst: SPDIF
- Better: Single AES/EBU
- Better Still: FireWire
- Best: Dual AES/EBU

FWIW dCS offer a similar connection methodology -- dues AES/EBU (one for each channel) that can carry PCM or DSD. It’s a proprietary format and only compatible with other dCS DACs. However you can use a single AES/EBU to carry both channels instead if you prefer

So in the case of a full dCS stack you take 16/44.1 PCM out of the Transport to the up-sampler on one AES/EBU and then use a pair of AES/EBU from the up-sampler to the DAC to carry your choice of higher rate PCM or DSD. At the same time the transport gives you another pair of AES/EBU to carry the signal from any SACDs you may have.

I’d hope the Esoteric set-up is similar and you can configure the dual AES/EBU output to carry both channels on one. This would also explain why SACD is not available on a single AES/EBU - the Esoteric is the same as the dCS in this regard. Single AES/EBU is limited to 16/44.1 only.

I used to like DVD-A as well, but lacking a suitable transport sold off all my discs (at quite high prices) last year

Personally with the dCS stack I actually upsample 16/44.1 to DSDx2 -- to my mind that combination works best with the filters available ... high sample rate PCM seems over detailed and loses some of the intimacy and life in the recording

If you can and your kit supports it (as Esoteric does) you should look into an external master clock -- my experience here https://forum.audiogon.com/discussions/benefits-of-adding-a-10mhz-master-clock-to-a-digital-system