Confused about S/PDIF "75 ohm" specification

[Jam_Master_J]

So if I go with the Canare connectors I won't have a true 75 ohms but it should still work well enough? I don't really feeling like modding my Pioneer source and x-dac for BNC connections.

 

[lan]

I think I'll have to change some of my RCAs to BNCs next. It's pretty much a termination swap, nothing else to change?

How's AES/EBU? It's 110ohm on 3pin XLR?

 

[bryman79]

Quote:

Originally Posted by Jam_Master_J So if I go with the Canare connectors I won't have a true 75 ohms but it should still work well enough? I don't really feeling like modding my Pioneer source and x-dac for BNC connections.

If the receiver chip is able to lock onto the signal, then it will work. And since most commercial stuff that do make sound have RCAs, it will probably work. But note that sound quality will be affected.

No one here, or at DIYAudio in that thread I linked to, diagree that impedance mismatch cause reflections which degrade sound. So it is really up to you how good you want your equipment to sound. But like Garbz said, why go with the Canare RCAs when at the very least you will be plugging it into an RCA bulkhead with ~25 Ohm impedance? Putting aside the fact that those who have measured these connectors say they are not true 75 Ohm, you will still have the impedance mismatch. Thus, you might as well save your money and go with any old RCA connector.

Bryan

 

[Jam_Master_J]

So for typical, consumer level electronics a "true 75-ohm" connector will have no actual advantage over a more affordable Canare F-10 or other low-cost connector?

 

[pburke]

Quote:

Originally Posted by Voodoochile Canare does make true 75 ohm RCA fittings....

they don't make a 75 ohm RCA jack, though...


but then there are some folks who say there' no such thing as 75 ohm RCA. Enter the WBT nextgens - maybe they actually are 75 ohms with the matching RCA connector, but then it'll take you $300 for a set of jacks and plugs to find out if that's really the case. Check over at DIYaudio.com's digital forum for the endless discussion about those plugs.

Bottom line - get a $6 high grade coax 75 ohm plug, and a $10 coax jack, also 75 ohm, add proper belden coax and you just saved yourself a bundle over the audiophile solution, plus you KNOW your cable and connectors are made for the job.

Peter

 

[Garbz]

Ian XLRs are infact 110ohms however IIRC they do introduce some kind of interaction problems since the signal is balanced and not running through 3 separate Coax connections. It is however much better then S/PDIF through RCAs.

Jam what you say is true. The 75ohm mark is simply the latest marketing BS. Unless both connectors are matched using them won't make a grain of difference.

And what peter also fails to mention is that his coax connectors + belden cable often will easily outperform any $1000 digital interconnect you'll find.