Okay, figured a roundabout way to at least test my NOS-1704 when it gets here to ensure that it technically functions.
Asus Maximus VII Hero Motherboard S/PDIF (Realtek selected in Foobar/JRiver) -> Audio-GD NOS-1704 -> Sound Blaster DBpro RCA -> Sound Blaster ZxR (Default Device) "Listen to Device" on the DBpro.
I'm listening to it like this right now (Realtek S/PDIF -> DBpro S/PDIF -> Listen to Device on ZxR) without the Audio-GD in the sequence and it actually doesn't sound that bad. I was half expecting it to destroy my headphones or something, so I plugged in my Sennheiser HD598s in case something went awry (really, a $150 headphone as a guinea pig?).
I can also perform RMAA/REW measurements using the same method to ensure nothing is horribly out of whack.
I might also pick up a super cheap amplifier to test the chain properly before I get the DI-2014. Or if I'm not feeling lazy I can dig up the X-Fi Titanium HD and simplify things a little by using its RCA line in from the NOS-1704 and I can play things without the "Listen to Device" crap.
Edit: Or I can be a little less stupid and use the DBpro's S/PDIF Out -> NOS-1704 -> DBpro S/PDIF In. It measures itself quite well (much better than the Realtek ALC1150 or whatever S/PDIF my motherboard outputs with).
http://www.basshead.club/measurements/zxr/dbpro_dbpro.htmlEdit 2 (don't want to keep polluting the recent posts column): I ordered a review unit of the Project Polaris from Garage1217 that'll come this week. I'll compare it directly with the Liquid Carbon as well. I don't want to get a fancy new NOS-1704 DAC and sully my first impressions with a crap amplifier.
I'm hoping that after listening to the NOS-1704 for a bit from TOSLINK, I'll get audible improvement using the DI-2014. If I don't, then... welp. I'm not a clinical listener, so it's possible I won't hear a difference, especially combined with the forgiving nature of NOS dacs. It might take a Yggy, Master 7, etc. to show improvements with the converter. Which is what you pyrates are for.