See Why Audio
Member
- Joined
- Apr 25, 2007
- Messages
- 28
Hi all,
I've been pondering the best way to declick and restore audio to create a DVD-A from CD-4 vinyl.
My most pressing question is:
Is it possible to create a DVD-Audio disc, or take cleaned-up stereo analogue straight from sound card, with the clicks and glitches previously treated and replay this signal through a CD-4 demodulator to obtain a new clean 4 channel recording?
I've been restoring SQ records to DVD-A for a while now and I'm getting great results with script decoding in Adobe Audition by declicking before decoding but does this approach work with CD-4? I'm aware that I can always restore the decoded 4 X CD-4 channels but it's more than doubling my workload and besides my restoraton and declicking techniques work better in a stereo scenario.
I have an Ortofon MC25FL (the FL stands for 'fine line' apparently) with a stated frequency response of 20-22,000 Hz but I just made a test recording (in stereo at 192 Khz sampling) of a CD-4 LP and the recording shows a very strong signal up to and beyond 50Khz with the 30Khz modulation showing up as a well-defined line while slightly 'above' and 'below' 30K forms a kind of water-line reflection of the carrier. Just by looking at it I feel it MUST work with a decoder. (Err, but as yet I haven't obtained one)
As far as I can see, I can eliminate most clicks and glitches in the audio regions well below 30Khz while leaving the carrier almost entirely untouched. But I don't know if this is allowable! Anyone? Where does the 'audio' end and the 'carrier' begin?
What is the uppermost necessary frequency response for the demodulation?
Here's a picture:
Furthermore, can I get away with working at a stereo 96Khz sampling rate which tops out at mono=48Khz? (to save computer space etc.)
Anyone tried this?
I would be happy to work with someone who already has a set-up to record straight to 4 channel from the source, if I provide the source as a cleaned up stereo DVD-A? But does a DVD-A player output the required frequencies? I can supply a good set of cleaned up WAVs instead...?
Would any of this work?
So many questions in one thread... excuse me
Colin
PS I need to hear from a couple of you regarding previous projects...
I've been pondering the best way to declick and restore audio to create a DVD-A from CD-4 vinyl.
My most pressing question is:
Is it possible to create a DVD-Audio disc, or take cleaned-up stereo analogue straight from sound card, with the clicks and glitches previously treated and replay this signal through a CD-4 demodulator to obtain a new clean 4 channel recording?
I've been restoring SQ records to DVD-A for a while now and I'm getting great results with script decoding in Adobe Audition by declicking before decoding but does this approach work with CD-4? I'm aware that I can always restore the decoded 4 X CD-4 channels but it's more than doubling my workload and besides my restoraton and declicking techniques work better in a stereo scenario.
I have an Ortofon MC25FL (the FL stands for 'fine line' apparently) with a stated frequency response of 20-22,000 Hz but I just made a test recording (in stereo at 192 Khz sampling) of a CD-4 LP and the recording shows a very strong signal up to and beyond 50Khz with the 30Khz modulation showing up as a well-defined line while slightly 'above' and 'below' 30K forms a kind of water-line reflection of the carrier. Just by looking at it I feel it MUST work with a decoder. (Err, but as yet I haven't obtained one)
As far as I can see, I can eliminate most clicks and glitches in the audio regions well below 30Khz while leaving the carrier almost entirely untouched. But I don't know if this is allowable! Anyone? Where does the 'audio' end and the 'carrier' begin?
What is the uppermost necessary frequency response for the demodulation?
Here's a picture:
Furthermore, can I get away with working at a stereo 96Khz sampling rate which tops out at mono=48Khz? (to save computer space etc.)
Anyone tried this?
I would be happy to work with someone who already has a set-up to record straight to 4 channel from the source, if I provide the source as a cleaned up stereo DVD-A? But does a DVD-A player output the required frequencies? I can supply a good set of cleaned up WAVs instead...?
Would any of this work?
So many questions in one thread... excuse me
Colin
PS I need to hear from a couple of you regarding previous projects...