xr100
Addicted to Fun and Learning
Sorry, in a particularly grumpy mood at the moment, should have added "do you have" and "please" etc. ;-)
The CD150 is basically a cost-reduced CD100. All the important parts are the same. Out of curiosity, I picked one up off eBay for a few quid. The CD100 sells for around £1000. Insanity.It's Philips first 14 bit D/A converter (2xTDA-1540S lowest grade epoxy packs) strapped onto their first 4x OS filter in the cheapest CD player they could bring to market in 1985.
Also compare apples with apples. It's 16/44 not 24/44 which all ASRs DACs get tested with- a format that doesn't really represent the majority of files or physical content does it?
And it beat its spec of 0.005% by a decent margin. And what is your A/D's contribution BTW?
Don't get me wrong, the Philips CD-150 was a horrible cheap nasty thing, but let's put its performance into perspective- it's actually quite good.
I can post a more comprehensive set of measurements tomorrow if you're interested.Frequency response? Or no suitable test tracks?
Can you elaborate, please?
IIRC, the early players weren't too hot in terms of having properly engineered/specified power supplies/isolation between sections. Performance could depend on how hard the transport has to work...
Philips still hadn't got the TDA-1541 (16 bit D/A) ready, refused to use the Burr Brown PCM-56 (which was new), so they pushed out a bunch of cheap players with nasty plastic moulded chassis, a massively cheapened CDM (laser mech) and their old lower grade TDA-1540 (wider tolerance) and virtually no user functionality other than the basics. I think Magnavox/Philips/Nordmende etc all got the cheap Philips machines.
After 8 weeks at NAP in Seacaucus NJ, it came back, played half a track and emitted smoke.
The CD100 sells for around £1000. Insanity.
So it was basically a clone of the CD100 then?Dad (I was only about 17yo) umm'ed and aah'ed and finally purchased an Akai CD-D1. A magnificent machine using twin TDA-1540Ds and the Philips 1st gen OS chipset, alongside a completely discrete tracking and focus front end.
For sure I should have said "Non-tonal components (noise-like) can be saved for human hearing by this method with much less success." But your example with two tonal components is a bad representative of the signal I meant - non-tonal (noise-like).Really now? Seriously? Now we're saying THAT?
Here's a narrowband noise signal, with the same plotting as the original sine signal.
Yes, one could do wider band noise, but I'm pretty sure that the statistical approach to detection will require endless explanations.
View attachment 48732
Oh, look, there's the noise signal in the output. Yes, it's noisier, but it's still detectable and this is purely by analytic methods.
Or just wide band noise...For sure I should have said "Non-tonal components (noise-like) can be saved for human hearing by this method with much less success." But your example with two tonal components is a bad representative of the signal I meant - non-tonal (noise-like).
And yes, I'm serious, may be too peremptory sometimes, but I'm sure you can cope with this.
May be the tail from some percussion ...Or just wide band noise...
Thanks to this discussion the origin of my terminological confusion is pretty clear now (for me at least).I had to Google the above terms and it seems that their origin is in structuralism/post-structuralism/linguistics?
Leaving aside their validity, I am all for broader and cross-disciplinary views but it is clear that you are mixing categories and getting into an epistemological mess here.
Probably, they could be used to look at, say, a "bitcrushed" sound in a recording (as discussed in the other thread.)
What is being discussed here, though, is the application of dither to linearise quantisation, as set out in the ("narrowly" (!) defined) discipline of information theory. No "broader" perspective, valid or otherwise, is needed.
And, I thought the objective of the "DF Metric" was to identify audio equipment and/or processes which yield perceptual transparency?
For sure I should have said "Non-tonal components (noise-like) can be saved for human hearing by this method with much less success." But your example with two tonal components is a bad representative of the signal I meant - non-tonal (noise-like).
This approach is a bit unusual and can be considered by someone as radical or even ridiculous (I mean you, j_j). But I'm pretty sure that sooner or later it will be accepted by audio engineers. I will state it in the different thread, where I already described/explained main concepts of df-metric. It will look more logical there and a bit offtop here. Give me a few hours.
I'm wed to another idea, df-metric is only an instrument for its realization.This is the crux of the issue, you are wed to your idea of a new metric and are not responding in a rational manner to peer review.
Done: https://www.audiosciencereview.com/forum/index.php?threads/philips-cd150-measurements.11296/I can post a more comprehensive set of measurements tomorrow if you're interested.
And indeed below LSB the dither can be considered as mathematical operation that linearizes behavior of quantization operation and thus preserves some info from below-LSB region of a signal. In this case the dithering can be really considered as formal/math operation. So, classification of dithering depends on what case - p1 or p2 - is considered.
It does work universally. My first exposure to dithering was in the 1970s in capturing photoacoustic interferograms, decidedly nonperiodic.Not a domain that I have much, if any, familiarity with. However, I don't think the "signal" could be considered the information that is lost through rounding, but rather the signal is the "trend;" a moving average filter being a basic example of a method to extract the "signal" out of "noisy" movements in price. IOW the quantization error is below the "noise" anyway.
For sure I should have said "Non-tonal components (noise-like) can be saved for human hearing by this method with much less success." But your example with two tonal components is a bad representative of the signal I meant - non-tonal (noise-like).
And yes, I'm serious, may be too peremptory sometimes, but I'm sure you can cope with this.
Or just wide band noise...