Bit accurate real-time recording

[Philgood]

I was starting to doubt about the possibilty

to make "perfect" copys of cd

through the optical in of my MD after i read this

Indeed, the optical input seems pretty suspect to me, certainly not providing the kind of bit-accurate transfers you normally expect from such an input - it resamples even 44.1kHz inputs, and as mentioned above, goes through the level control - though having said that, you'd have to have good ears to detect the difference unless you'd changed the volume.

but what about the SYNC-REC function, will this bypass

the level control...?

i guess i have to make bit comparison after uploading

the different variants and letting you know about the results

[ozpeter]

Yes, but the audio is still resampled. So if for instance you invert the phase of a ripped version against a optical in version, which should result in silence, you get silence for a very brief moment, and then the audio returns as the two versions go out of sync.

I'm not claiming you'd hear the difference - but they are different.

[Philgood]

thanks ozpeter, you saved me some time :-)

[dex Otaku]

This is all sort of beside the point - if you're talking about recording to a lossily-compressed format [like SP mode on legacy MD] then there's no such thing as bit accuracy anyway, even if you knew that the stream reaching the encoder is exactly what leaves the player.

[Philgood]

thanks dex, i just thought with recording my old MD discs

from a Tascam MD-350 i have at work to my Hi-MD in PCM

through a digital-to-digital connection i can overcome

the limitation with sonicstage to transfer

"oldschool"-SP recordings in a bit accurate manner...

anyone knows how much you've to pay for that modified

MD-SCSI-drive from www.esdl.co.uk, just sent a mail

but holidays are near so i think i won't get an answer

this year

the specs are "PRO"

Edited December 19, 2005 by Philgood

[dex Otaku]

Ahhh, see, you're talking about another something entirely different.

Excepting the MD drive you're looking at, it's the same thing, though - you can't bit-perfectly copy an SP mode MD. Any playback means decoding the SP content to PCM, which means a generation loss is guaranteed.

The MD drive you're looking at will, with the right software [presumably using their tools] allow direct extraction to ATRAC files, however, you still have the same problem - you can't write ATRAC SP to any other format and have it usable, so to write to any other format still means transcoding to PCM and then possibly to something else.

[Philgood]

very interesting dex,

so the output format of the data stream

at the optical output of my HiMD is always

PCM and is re-encoded to ATRAC at the source

MD device ?

[dex Otaku]

Your HiMD has no optical output. It's in only.

The only format support any of these devices has over SP/DIF [optical] is PCM; anything being played from MD [since there currently are no HiMD decks with optical outputs] over SP/DIF will be PCM.

Basically it's like this:

playback device -> PCM -> ATRAC/ATRAC3 -> record on MD

play from MD -> ATRAC/ATRAC3 -> PCM -> other recorder or converter

Some professional MD equipment allows copying of the actual ATRAC tracks off the discs. The software mentioned at the site you linked to is made for this. It's still not entirely useful though, unless you're copying straight back to MD again, because nothing else that I'm aware of supports ATRAC [sP mode].

Yes, though - over optical, the only format understood by these devices is PCM; while recording, it gets converted to whatever format you're recording in - unless you're recording on HiMD in PCM mode, in which case bit-perfect copies are still basically imossible as the entire stream in resampled. During playback, non-PCM recordings get converted back to PCM and then either sent over SP-DIF [in the case of MD decks] or converted to analogue [in the case of any deck or portable, whether MD or HiMD].

It's still not really clear to me exactly what you want to do, though. You started off talking about making bit-perfect copies of CDs, then went into talking about copying MDs losslessly [an entirely different process]. So really - what exactly is it that you need to do?

Cheers.

[Philgood]

a great summary dex,thanks

well, i guess my posts are really something confusing

actually i was interested in how the optical-in of my HiMD

works either i'm making PCM copies of CD's or want to transfer

old SP MD's to computer for to burn them on CD or

to copy it back to MD(formating in HiMD for saving valuable MD disc's)

I just read here http://forum.ecoustics.com/bbs/messages/1/92.html

about the costs for the previous mentioned Software/Hardware Bundle

from http://www.esdl.co.uk

That's 5000 euros!!!