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Post by DaveC on Sept 29, 2014 13:01:53 GMT
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Post by MikeMusic on Sept 29, 2014 14:23:48 GMT
First CD player I ever heard might have done !  Horrid |
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Post by zippy on Sept 29, 2014 14:51:07 GMT
Those were the days (my friends !)
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AlexM
Rank: Duo
Posts: 30 
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Post by AlexM on Sept 29, 2014 15:47:38 GMT
Would anyone care to hazard a guess about the THD of a -65Db signal on vinyl? or tape?
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Post by DaveC on Sept 29, 2014 15:59:07 GMT
Virtually nothing at all, the unbroken signal will still be all there, albeit with a bit of noise. Even lower the whole signal will still be there with more noise. Hence vinyl to some doesn't have the low level issues digital has.
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Post by MartinT on Sept 29, 2014 16:35:12 GMT
This is Chris Frankland, right? The man's writing is mostly deranged. There is hardly anything he writes that I can agree with. Please give me some of the American or valve products that were around at the time of Linn/Naim and I will make you a more musically pleasant system, not one that is always on the edge of going out of adjustment. He even mentions EAR: there you go, for starters. Yes indeed, the red book spec may deliver 40% THD at -80dB or so, but it's not news and dithering was introduced to properly bury it in noise.
I'm amazed that HFW wants to associate themselves with the writings of TFR.
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Post by danielquinn on Sept 29, 2014 16:42:43 GMT
If I remember correctly a certain n keywood did the measurements.
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Post by DaveC on Sept 29, 2014 16:51:01 GMT
Makes you think though ? dithering is never going to reconstruct the original signal if it isn't there to start with ?
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Post by MartinT on Sept 29, 2014 16:57:22 GMT
Agreed, the idea being that by the time you get to -80dB or thereabouts, a little noise sounds better than almost-subliminal-but-not-quite low level distortion.
I don't think anyone would hold up red book as the ultimate digital format today, but what's been achieved with it is way better than anyone had imagined back in 1984. Thank goodness Philips didn't win the argument or we'd be suffering 14/44 format, and that would hurt.
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Post by lurcher on Sept 29, 2014 21:20:56 GMT
Dithering is added at the recording side, its not about reconstructing the signal, its about being correctly recorded in the first place, ie preventing the digitisation process from adding distortion. If you go out of your way to intentionally record a undithered signal then yes, you can get those results.
At the time 16 bit was considered more than good enough, you would have next to no chance of getting a -80dB signal from vinyl, and it would take some effort from tape. Saying the "unbroken" signal is still there is like saying you can see the stars at midday, yes, they are still there, but that doesnt help you seeing them. Maybe a clever DSP correlator could pull a 1khz signal at -80dB from vinyl, but thats because it knows where to look. Good luck getting a wideband (music) signal out of it.
Don't get me wrong, I love music from vinyl, but misinformation doesnt help vinyl or digital.
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Post by MartinT on Sept 29, 2014 21:29:13 GMT
Dithering is added at the recording side, its not about reconstructing the signal, its about being correctly recorded in the first place Yes indeed, I didn't make that clear but as you say, it's about adding noise at the quantisation stage in the ADC. The effect on replay is that the noise floor is slightly raised but the sound quality at very low levels is much more natural. I have a test CD with recorded low level tracks with and without dither. The difference is startling. |
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Post by DaveC on Sept 29, 2014 21:37:38 GMT
Maybe a clever DSP correlator could pull a 1khz signal at -80dB from vinyl, but thats because it knows where to look. Good luck getting a wideband (music) signal out of it. Nothing like that is needed. However our ears can detect it easily, as can a spectrum analyser. In vinyl it is there, in digital it is not. Oh, and yes the stars really are there all the time................... not that it is relevant. This is why 96/24 and higher are working so very well, the old CD never was up to it. Remember the Tomorrows World episode ? |
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Post by MartinT on Sept 29, 2014 21:41:07 GMT
"Perfect Sound Forever".
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Post by ChrisB on Sept 29, 2014 22:06:03 GMT
Pure Perfect Sound Forever!
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Post by DaveC on Sept 30, 2014 6:11:50 GMT
I had that Sony CDP-101 on launch, the only CD available being Chariots of Fire !
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Post by MartinT on Sept 30, 2014 6:27:39 GMT
I was a little later that year and bought a Philips CD-104 in a show deal that included a bundle of discs. I wish I had kept that player, it was well built. I'm pretty sure it had the cast metal swing-arm drive before they went all plastic.
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Post by DaveC on Sept 30, 2014 6:36:28 GMT
Me too, but at least I kept all my records !!
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Post by ChrisB on Sept 30, 2014 7:02:07 GMT
I had the Mission DAD version of that machine Martin - the drive was built like a brick nettie. A friend still uses it 23 years after I passed it on to him!
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Post by MartinT on Sept 30, 2014 7:18:35 GMT
Me too, but at least I kept all my records !! Luckily, I kept mine too! |
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Post by MartinT on Sept 30, 2014 7:19:59 GMT
A friend still uses it 23 years after I passed it on to him! Impressive! |
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