S/PDIF connection question

T

Tom Manchester

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Jan 11, 2011
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Delaware
www.electrosoundsystems.com
I've never really used the RCA coaxial S/PDIF connection on any of my Yamaha boards, so I was reading up a bit on the protocol and it got me thinking:

If I run a CD player, such as my Denon DN-S1200 with it's Coaxial digital out into the RCA Digital input on say, my LS9, would there be an issue since the CD player is running at 44.1K and the console is clocked at 48K?

I just hate to have those digital 2 track inputs go unused!
 
Re: S/PDIF connection question

Seems to me when I tried something like this with the different rates that the music came through but was pitch-shifted due to the unmatched rates.
 
Re: S/PDIF connection question

TJ Cornish said:
It depends on the particular Yamaha board - I believe the M7 and up have them, LS9 doesn't, DM1000/2000 do, not sure on 01v96.
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That might work out ok. On mid-size festivals I usually put my DM2000 at FOH where the CD player would be anyway, and my LS9-32 on monitors. I'll have to dig into the DM2K manual and see what it says about SRC's on the SPDIF input.

Having it work on my 01V96 is not really a big deal since it has the 4 TRS inputs that are really only useful for playback inputs anyway and I can just use them.
 
Re: S/PDIF connection question

Milt Hathaway said:
According to this old thread: http://srforums.prosoundweb.com/index.php/m/170823/0/

You'll have to set change settings in the console to allow it to see the CD player as the word clock. Of course, this will mean your console now runs at 44.1.
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44.1 isn't any big deal. It's running your show on an outside clock source that's bitten me in the past. Had just that situation, and a CD player that dropped its clock output when changing CDs. The LS9 would lose audio for a few seconds while switching back to its own internal clock.
 
Re: S/PDIF connection question

Ok, just checked the manual for the LS9 and DM2000. The DM2K has a page in the menu where you can do sample rate conversion on both the digital ins and outs. The LS9 seems to clock to whatever is going into the SPDIF input. I could see that getting really dicey if someone opted to use just the 2-TRACK SPDIF output to a CD burner but continued to use the 48K internal of the LS9 as the word clock.

I recall one instance in which I was doing a series of concerts and recording them (as a courtesy) via the LS9's internal recorder. Whoever was handling the editing on the other end was insisting that I change my console to 44.1 because I guess it was making life difficult for him. I told him no-can-do and I guess they finally gave up and started bringing out their own HD recorder and taking an analog output off my board, lol.
 
Re: S/PDIF connection question

what is the problem with using 44.1 instead of 48k? I can see problems clocking my whole rig from a cd player but who cares if its 44.1 or 48k. I think I run my 01v96 at 44.1 and couldnt hear the difference the day I tried 96k.
 
Re: S/PDIF connection question

There's nothing wrong with running the board at 44.1k, other than slightly more latency compared to higher sample rates, and a lower Nyquist frequency, which may or may not (probably not) be audible in a live setting.

The problem is that the CD player's 44.1k and the board's 44.1k won't be exactly the same, so without word clock syncing - declaring someone to be the gold standard of 44.1k and then everyone lining up the bits with that, is timing will slip and you'll get clicks and potentially other nasty junk.

Friends don't let friends use unsync'd gear.
 
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