S/PDIF cable question

jfrog

jfrog

uber-nerd
I have a question about S/PDIF cables....

I've been transferring music from my Fostex VF-08 to my computer via the S/PDIF ports. (I have a M-Audio Fast Track Pro interface) Recording using Reaper.

It's working fine, except occasionally some noise gets transferred...and I'm wondering if it's the cables. I'm using a video cable (75 ohms impedance, same as S/PDIF) If I buy an S/PDIF cable is it going to be shielded any better than the video cable? I'm trying to determine if I'm barking up the wrong tree - maybe it's something other than the cable.

Thanks.
 
I've been using a video cable - the better quality cheapos with gold ends... I didn't know they made specific SPDIF cables. But I haven't had any noise problems.
 
some noise gets transferred
Click to expand...
What's the noise and is it in the same place every time or does it come up in various places during playback?
Bit & sample rate would be good to know too.
 
Jim Lad said:
What's the noise and is it in the same place every time or does it come up in various places during playback?
Bit & sample rate would be good to know too.
Click to expand...

the noise is a kind of buzz that occurs. I recorded the same song a couple of times and the noise seems to be a different locations...which could indicate interference. It could be a sync problem. I'm not sure how to verify that, though. The Fostex is supposedly transmitting at 44.1 kHz, which is what I set reaper for.
 
jfrog said:
I have a question about S/PDIF cables....

I've been transferring music from my Fostex VF-08 to my computer via the S/PDIF ports. (I have a M-Audio Fast Track Pro interface) Recording using Reaper.

It's working fine, except occasionally some noise gets transferred...and I'm wondering if it's the cables. I'm using a video cable (75 ohms impedance, same as S/PDIF) If I buy an S/PDIF cable is it going to be shielded any better than the video cable? I'm trying to determine if I'm barking up the wrong tree - maybe it's something other than the cable.

Thanks.
Click to expand...
Those yellow video cables are usually shielded fairly well. Unless you really have a shitty one, I doubt it is caused by EFI or RF, unless maybe you taped/bundled the AC cable directly against the s/pdif cable or something. Are there any AC or speaker cables near it?

Otherwise, it could possibly be a ground loop, (showing up when something in the building turns on or off.) Are both boxes plugged in to the same AC outlet? They should be.

To help analyze this problem you could move the entire system to another room or another building and see if it still does it.
 
s/pdif is a digfital transfer, so RF interferance will not cause noise like it would in the analog world.

You could be having clocking issues. You need to set the clock on your computer interface/soundcard to the s/dif input. That way it will get the clocking information from the fostex and everything will work the way it's supposed to.
 
I decided that it probably isn't the cable...I used to use the same cable to go from the Fostex to my Pioneer CD-R deck, with no problems. It probably is something not syncing correctly.

I think I have them both set the same...the Fostex output is 44.1 kHz, so that's what I set reaper to. I don't think there's any adjustability in the M-Audio box, but I'll read through the documentation & verify that.

Thanks for all the suggestions.
 
jfrog said:
I decided that it probably isn't the cable...I used to use the same cable to go from the Fostex to my Pioneer CD-R deck, with no problems. It probably is something not syncing correctly.

I think I have them both set the same...the Fostex output is 44.1 kHz, so that's what I set reaper to. I don't think there's any adjustability in the M-Audio box, but I'll read through the documentation & verify that.

Thanks for all the suggestions.
Click to expand...
There has to be some way to make the m-audio box slave to the s/pdif input, otherwise the input would be unusable.
 
Farview said:
There has to be some way to make the m-audio box slave to the s/pdif input, otherwise the input would be unusable.
Click to expand...

the users guide for the m-audio box says to do this in your recording software. which I thought I did. It also suggests adjusting the latency, (I had also thought of that on my own) but I tried to do it, the option was "grayed out". There may be another way. Hopefully I'll have time to play around with it this weekend.
 
Unless it's different in Windows or my memory is faulty, sync source is in the M-Audio control panel, not in your audio app. Set the sync source to S/PDIF. If your Fostex supports syncing to an external S/PDIF source, you could also make the M-Audio be the master. Either way.
 
I did some recording today thru the M-Audio box...line in as opposed to the s/pdif that I was doing last week. Occasionally there still is the slight buzz...but not as often. My conclusion, then, is that it has nothing to do with the syncing of the s/pdif's, but the box itself. &$%^!!!!
 
You must log in or register to reply here.
Back
Top