AES to S/PDIF Cabling/Signal flow (Tascam UH 7000)

[Balcony Falcon]

I'm having a little issue here and would be greatly appreciative anyone could shed some light on my confusion.

I recently purchased a Tascam UH 7000 after reading the review in Tape Op, and sound wise, lives up to the hype. Knowing that it only has 2 ins and 2 outs and AES digital in/out, I planned on pairing it with my Focusrite Scarlett 6i6 (which has SPDIF inputs and outputs). I had also read that the digital AES ins and outs could be switchable to accommodate SPDIF via the routing mixer.

Most of these require a conversion box to go from AES to SPDIF, but as advertised you can just purchase a special cable and bypass the converter altoghether. The only issue is the impedance of AES is 150 ohms and SPDIF is 75, it would look like an XLR to RCA male cable, but I don't know which impedance to buy. To be honest, I've made the switch from analog recently and don't know anything about Digital ins and outs to begin with.

How would I use the UH 7000 as an A/D converter, cabling and connection wise?

I hear you can use it as a standalone mic preamp as well, would I just connect the XLR Outputs of the unit to the XLR inputs on the Focusrite Scarlett or my Tascam M-30 Mixer?

The manual is limited in info at best (unlike the old Tascam Analog Manuals of the 1980's, those were BOSS). Tried contacting Tascam and they havn't gotten back to me (one week ago). Sorry to be long winded, any advice would be great, thanks!