1 Topic by gleeman (edited by gleeman 2011-07-31 19:03:33)

  • Registered: 2007-10-27
  • Posts: 10

Topic: analog -> digital -> analog -> digital

Dear rme forum,

I'm new to madi technology, so forgive me if the question might seem dumb to some people.
Let's pretend that I would like to transport 32 channels of audio from a live stage to a FOH analogue console (because I find it faster to work with analogue mixers), but getting rid of analogue snake cables and having a single fiber optic (more reliable, lighter). In this case I suppose I would need an m-32 AD and an m-32 DA to transport the signal. Then let's pretend again that I would like to record all channels into a DAW using the mixer direct outs. I would need another m-32 AD and an HDSPe card.

The question is, does this conversion analog -> digital -> analog -> digital degrade the sound? My answer would be "maybe not, if every m-32 is properly synced to the same clock", but I suspect that maybe some noise would be added because of the double conversion. Please don't take into account the eventual coloration in the sound produced by the analogue console, but only the process of double digital conversion.

thanks in advance.

  • vinark
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Re: analog -> digital -> analog -> digital

No degradation. But AFAICS you would be able to record the incoming digital signal before the mixer, which would spare you another converter to buy.

Vincent, Amsterdam
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3 Reply by gleeman (edited by gleeman 2011-07-31 19:57:16)

  • Registered: 2007-10-27
  • Posts: 10

Re: analog -> digital -> analog -> digital

You're right, but I would not be able to get advantage of the console's preamps.
The other problem of such a setup would be that I would need an external phantom power unit for microphones. In the end even if the idea of not having to deal with long snake cables is tempting, this solution seems impractical.

4 Reply by Randyman... (edited by Randyman... 2011-07-31 21:08:52)

  • From: Houston, TX
  • Registered: 2007-05-11
  • Posts: 1,191

Re: analog -> digital -> analog -> digital

There are plenty of "Digtial Snake" type products that include preamps and phantom power, but transmit over standard GigE Ethernet cables or in some cases FC type fiber cables.  Let your fingers do the walking wink  Using a M32AD and M32DA seems a bit overkill to me - and as mentioned won't include any mic preamps at the stage - and won't have any "returns" either!!!  But I'd love to have a M32AD in my recording rig!!!

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5 Reply by MC

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  • Registered: 2007-04-06
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Re: analog -> digital -> analog -> digital

You can not digitize the mic signals on stage to feed it to the preamps of your FOH console. You will need to have complete preamps on stage, not only phantom power.

Regards
Matthias Carstens
RME

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  • Registered: 2007-10-27
  • Posts: 10

Re: analog -> digital -> analog -> digital

I know this topic has become pure philosophical speculation, but can you elaborate on this Matthias? Is it because the m-32 cannot digitize low voltage signals? Impedance mismatch? What else?