Digital cable connection questions

[Mister Crash]

I'm currently awaiting the arrival of a Wadia 581i SE CD player. This particular player has an array of digital inputs and outputs, but they are a little different from what I'm used to seeing:

- Glass optical (I think this is the AT&T ST type of optical input)
- Coaxial, with a BNC connector
- Toslink
- AES/EBU

The manufacturer states that the preferred connection quality would be glass optical > AES/EBU > coaxial BNC > coaxial RCA > Toslink. However, my other gear has either a Toslink output or a coaxial RCA output (the bottom two in terms of quality). I want to get the most out of my gear, so I had a few questions about the equivalence of these digital signals:

1. Do Toslink and AT&T optical carry the same type of signal? If I had a cable that had a Toslink connection at one end and an AT&T connection at the other, would I be able to plug a source with a Toslink output into the AT&T input? Or are these fundamentally different transmission standards?

2. Would a BNC out to a BNC in be fundamentally better than an RCA out to a BNC in? What about a BNC out to RCA in? Is it more important to have a true 75-ohm connection at the input or the output?

3. Are there any converters out there that can change a coaxial signal to an AES/EBU one? What about a Toslink signal to an AT&T one? If so, would the resulting signal be constrained due to the limitations of the source signal? In other words, if my gear has a coaxial out, would there be any advantage gained in transforming it to an AES/EBU signal?

[1UP]

The issue is of impedance mismatches causing signal reflections, leading to possible jitter effects.

Native XLR or BNC on both ends are preferred mechnically, cause they would take the connector's characteristics out of the equation. RCA connectors/adapters are just suboptimal in this regard. What are you going to connect it to?

In the real world - I'd say, pah, don't sweat such things, enjoy your Wadia!

[bigshot]

Toslink will work just as well for you. Not to worry.

See ya
Steve

[HighLife]

Lots of dicussion of the use of optical or digital coax. Just search Optical vs Coax and you will get tons of info on it. I did a ton of reading on it.

Im stuck atm using optical cause my ce595 only has a optical output and no coax.

[Mister Crash]

Well, I've read a fair bit on the debates between optical vs. coaxial, but I was more interested in the quality variance within optical digital (Toslink, AT&T) and within electrical digital (RCA, BNC, AES/EBU).

I have a US Playstation 3 (using Toslink) and a Japanese Playstation 2 (using Toslink), which I currently run through an A/V switch to access the single Toslink input on my DAC. I am also strongly considering getting a Wadia 170i iPod dock, which has an RCA coaxial output. It would be nice if I was able to take one of the Toslink sources and convert it to AT&T optical, but I'm not sure if the connection is the only difference between the two, or if they use fundamentally different frequencies of light.

It sounds like I'll have to keep my switch for the Toslink input, and get an RCA/BNC cable to plug in the coaxial input.

[1UP]

There are converters and switchers
M-AUDIO - CO2 - Coaxial/Optical Bi-Directional Converter
Audio Authority® - Product Details: 1177A
Audio Authority® - Product Details: 977RPO

but jeez, you're using a Wadia to decode a PS3...

[HighLife]

Originally Posted by Mister Crash

Well, I've read a fair bit on the debates between optical vs. coaxial, but I was more interested in the quality variance within optical digital (Toslink, AT&T) and within electrical digital (RCA, BNC, AES/EBU).

I have a US Playstation 3 (using Toslink) and a Japanese Playstation 2 (using Toslink), which I currently run through an A/V switch to access the single Toslink input on my DAC. I am also strongly considering getting a Wadia 170i iPod dock, which has an RCA coaxial output. It would be nice if I was able to take one of the Toslink sources and convert it to AT&T optical, but I'm not sure if the connection is the only difference between the two, or if they use fundamentally different frequencies of light.

It sounds like I'll have to keep my switch for the Toslink input, and get an RCA/BNC cable to plug in the coaxial input.

I know what you were talking about. The info is still there on the differences between optical cables. Since most of the talk about optical cables include some talk of coax vs optical.

[infinitesymphony]

Regarding the actual transmitted information, it's all sent in S/PDIF format (the consumer version of AES3, a.k.a. AES/EBU). The only differences are connector quality, as described above, and the quality of the implementation of a given connector type in both the sending and receiving device. Maybe Wadia spent extra time on the glass TOSlink output, or for whatever reason, it measured best during their testing procedures... Or it could just be one of those arbitrary suggestions that a manufacturer sometimes makes.