Reading about connecting digital coax SPDIF stuff is making my head spin. All the talk of 75 ohm characteristic impedance. I understand a lot of the concept, and how RCA connectors cannot be true 75 ohm due to their physical designs, but it also seems that some now get "close."

A lot of commercial transports do use RCA digital coax, though..... Are most of them NOT 75 ohm, or even trying to be by using "75 ohm RCA" jacks? They just use regular RCA jacks and it is what it is? How do they deal with this?

I'm hung up is on what exactly I need for my build, and I'm wondering how I should wire up my buffalo when it gets here?

I was planning to use my motherboard's (ASrock X58 extreme) soundcard's digital coax output (RCA) as the transport (capable of up to 192/24). I have no idea if it uses a "75ohm" RCA connector or if it's just a regular old RCA connector? Probably whatever the standard there is for commercial digital coax output.

My biggest question is... what connector should I use for the SPDIF input? Should I use a 75 ohm BNC bulkhead for the input, and then connect it to my computer using a BNC to RCA digital coax cable from bluejeans for example (who make as close to 75 ohm rca digital coax cables as possible, apparently, and will do an RCA to BNC one)? Or should I buy a canare "75 ohm" rca jack like the RJ-R ones and use that as the digital coax input? Should I just use a regular old RCA jack?

In each of these cases, I'm also really confused on how I would actually wire it to the connector on the buffalo ii board itself. Whould I use regular old wire? 75 ohm coax? If 75 ohm coax wire, won't the way I will have to strip it and connect it to the green connector on the buffalo mess with the 75 ohm characteristic impedance anyway?

Or should I completely avoid SPDIF and try to find a USB to I2S converter or something, like this one?

Will any of these choices even impact sound quality in a noticeable way.... am I overanalyzing this aspect? Should I just buy a simple RCA jack and wire it up with normal wire?

I literally have no idea what I should do! There are so many people who have set up their buffalo dacs by now, some of which must have a similar setup, but I really can't find any discussion on how people actually got the SPDIF signal into their boards?

Thanks! A huge weight off my shoulders! The whole 75ohm with RCA is crazy... is there really not much difference for my configuration?

Sounds good. I was really more worried about it working but having lesser sound quality without me even realizing it. I figured either way would lock and work and what not, but based on what I was reading, it sounded like people really hear a difference when it's 75 ohm throughout (in general... not necessarily with the buffalo specifically, I couldn't find any reports on this).

Good enough for me! Thanks for all of your quick help!