Boost the SPDIF signal?

[Bob Zelin]

If you are using good quality COAX cable (video cable), you should have no problems. If you insist on using audio cable, convert the signal to AES/EBU (with a Flying Cow, etc.), and you can run up to 100′. Over 100′, you need 110 ohm audio cable (like Belden 1800B) which is expensive (this is audio cable too, and will allow you to run long runs of AES/EBU audio).

Everyone makes fun of good cable, and you are now experiencing what happens when you use the wrong cable to send a digital signal down a wire long distances. It’s ain’t voodoo.

Bob Zelin

[Sean Oneil]

I’ve tried lots of different video cables. The same cables have no trouble with SDI video.

I also used an impedence converter which allows you to turn the SPDIF it into balanced AES. Yet I still experienced signal breakup with a 50ft. XLR cable.

People tout the importance of high quality cables. While I don’t disagree with that, getting high quality cable like RG-6 is not the solution I’d like to go with. I believe that if your signal path is breaking up on low-quality cable, yet it seems to work fine on high-quality cable – to me using the good cable is still dangerous and too unreliable to be trusted. The signal path needs to be reliable enough so that it could still work on lower quality cable. Wear and tear, hot or cold weather, etc. These things mean that if the signal just barely makes it to begin with on good cables, then you could have problems later on when the environment changes for the worse.

Luckily though, I may have found a good solution. Can someone tell me if this box will re-clock the signal, thus giving me lip sync delay? Thanks.
https://www.hosatech.com/hosa/products/odl-276.html

Sean

[Bob Zelin]

you can send SPDIF on crappy RG59 video cable for 100′ with no problem. If you are having problems, the problem is not the cable, or the Blackmagic card. What are you trying to send to (what audio device are you having trouble with).

Bob Zelin

[Sean Oneil]

I think you’re wrong about that. 50′ wont’ work. Good (not crappy) 50′ 75Ohm RG59 doesn’t work here. BMD emailed me and said SPDIF does normally cap out at 10 meters (32′) and they provided a link to an extender device. I think the SPDIF interface and cable drivers just work differently than SDI, so you can’t apply the same facts and figures to each as far as cable length is concerned.