[Ardour-Users] Experience? Rework an external 44.1 KHz 16 bit recording

[Mark Knecht]

On Thu, Aug 19, 2010 at 9:18 AM, Ralf Mardorf
<ralf.mardorf at alice-dsl.net> wrote:
> On Thu, 2010-08-19 at 11:54 -0400, Paul Davis wrote:
>> On Thu, Aug 19, 2010 at 11:38 AM, Ralf Mardorf
>> <ralf.mardorf at alice-dsl.net> wrote:
>>
>> > A million years ago I copied using coaxial S/PDIF, but it wasn't a 75
>> > ohm cable, from my AIWA HD-S1 DAT to my Sony DTC-670 DAT and there was
>> > loss, not dramatic, but audible. I don't have coaxial usable for my
>> > sound cards, hence I would need to use a 2 m or 6 m optical waveguide.
>> > S/PDIF indeed seems to have loss.
>>
>> digital signal transmission isn't "lossy". it either works or it
>> fails. that's the whole point.
>
> Okay.
>
> Is 'lossy' just the wrong word? I 'guess' I did hear loss when doing a
> copy from DAT to DAT, using an audio cable, but a 75 ohm cable. I read
> about this as a common issue for optical waveguide in the audiophile
> mags at my dentist :D, but they do write a lot of nonsense. I always
> wondered why there seems to be loss when doing the S/PDIF copy from DAT
> to DAT, but at the same time DAT also is used to backup computer data. I
> guess for the computer it's not called DAT, but they use the same tapes
> and mechanics.
>
> Anyway, you explained why ripping the CD might be more safe, than using
> S/PDIF. Let's they at least for CD the fail would cause loss ;).
>
> Btw. thank you for the CD explanation,
> Ralf

If you used an audio cable to copy, you weren't really copying. You
were doing playback and record. That will be lossy.

You can put digital data on tape, and as Paul and others have said, if
you make a digital copy then it's lossless. It either works or it
doesn't. If you playback an audio recording held on DAT then that
digital data is turned into analog, and at the other DAT it's turned
back into digital. That always works but is lossy.

I'm assuming here that we're talking about an ADAT interface. If I'm
wrong about that assumption let me know. As far as I know ADAT
interfaces come in two or possibly 3 varieties:

1) Some sort of older style parallel wire cable. I don't own any of
this sort of equipment.
2) A laser interface to optical cable, which is what I use. (Glows red, right?_
3) Probably a spdif output.

All 3 are digital only TTBOMK. The DAT machine may also have built in
D/A and A/D. If you use those you get analog with all of it's inherent
beauty and faults.

- Mark