| From: | Don Cox |
| Date: | 8 Aug 2000 at 09:48:27 |
| Subject: | Re: Cd`s & Record Decks (OT) |
On 08-Aug-00, Lee M Hemenway wrote:
> Yes, just think of all the data that must surely be lost when the
> analogue signal is first converted to digital and then converted back
> to analogue when you play the CD. There is massive number crunching
> and error correction going on in there.
> The very fact that there is error correction going on when playing a
> CD says it all.
The point of error correction is _not_ to lose data. Provided the errors
are within the range that the RS can correct, there is no loss.
The problem comes when the errors _can't_ be corrected and values are
interpolated instead. There really should be an LED on the player to
tell you when that is happening.
Jitter in D to A and A to D circuits can cause considerable distortion.
Digitising at 96KHz instead of 44.1KHz will reduce this in proportion.
There's no error correction in a record player at all. If the output
from the cartridge isn't an exact copy of the shape of the groove, there
is no way to recover it. And the geometry alone prevents it from being
exact. Likewise, the disc cutter will not produce an exact copy of the
recording.
Almost all modern recordings are made on digital equipment, so there
will be one A to D and one D to A conversion, whether you are on vinyl
or CD. However, on CD the conversion is done at home, on cheap consumer
circuitry.
You can buy from Testament and other companies vinyl LPs made using
entirely analog methods throughout. Testament use EMI tapes from about
forty years ago, of very good quality.
Regards
Quote carefully and read all ADMIN:README mails