Author Topic: A CD player with buffering  (Read 659 times)

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Offline magic

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A CD player with buffering
« on: February 27, 2019, 09:37:31 pm »
I very much like this thing because it actually manages to be true while still being a bullshit product.

https://www.psaudio.com/perfectwave-memory-player/

Quote
It is a minor miracle that a CD mechanism works at all.

Between the mechanical devices controlling the laser, varying rotational disc speeds, disc wobble and the errors that must be corrected for even the best CD’s, getting perfect jitter-free music from your CD player is an elusive goal.
I wholeheartedly agree. Optical media are terrible.

Quote
The PWT Memory Player changes all that forever by first extracting the music from the CD or DVD and then placing it into our Digital Lens memory buffer. When you play a disc you are never listening to the real time stream from the CD or DVD. Instead, everything you hear comes directly out of memory in perfect, asynchronous jitter free fashion.

It’s easy to see this in action for yourself. Press play on the PWT’s front panel touch screen and then press elect. The disc will be ejected but the music continues to play for up to 5 seconds.
And that's a pretty decent solution :clap:

How come no one came up with this idea before? :-DD
 

Offline glarsson

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Re: A CD player with buffering
« Reply #1 on: February 27, 2019, 09:51:58 pm »
How do you think portable CD players (Walkman style, discman, etc) work?
 

Offline ebastler

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Re: A CD player with buffering
« Reply #2 on: February 27, 2019, 09:57:19 pm »
How do you think portable CD players (Walkman style, discman, etc) work?

Irony detector out of order?
 
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Offline glarsson

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Re: A CD player with buffering
« Reply #3 on: February 27, 2019, 10:09:55 pm »
Yes. Had to turn it off as the crazy people (AOC, genderbenders, flat earthers,...) gave false positives.
 

Online dzseki

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Re: A CD player with buffering
« Reply #4 on: February 27, 2019, 10:16:50 pm »
Why bullsit? Jitter free reproduction is a valid point and it takes some real effort to achieve it. It resembles to portable CD players, so what? Did they claim jitter (by digital means) free playback? No.
As to what does this cost is an other question, but if anyone would be hired here to build "premium" CD players, no one would do it for peanuts I am sure ;)
« Last Edit: February 27, 2019, 10:19:12 pm by dzseki »
 

Online wraper

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Re: A CD player with buffering
« Reply #5 on: February 27, 2019, 10:24:19 pm »
Quote
It’s easy to see this in action for yourself. Press play on the PWT’s front panel touch screen and then press elect. The disc will be ejected but the music continues to play for up to 5 seconds.
And that's a pretty decent solution :clap:

How come no one came up with this idea before? :-DD
IIRC relatively cheap portable CD player I had in the past had like 20 seconds buffer, many others had more. The problem with CD-DA is that error correction is far from perfect, so you need to rip CD at least several times to get a perfect bitstream without any errors.
 

Online dzseki

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Re: A CD player with buffering
« Reply #6 on: February 27, 2019, 10:45:47 pm »
Quote
It’s easy to see this in action for yourself. Press play on the PWT’s front panel touch screen and then press elect. The disc will be ejected but the music continues to play for up to 5 seconds.
And that's a pretty decent solution :clap:

How come no one came up with this idea before? :-DD
IIRC relatively cheap portable CD player I had in the past had like 20 seconds buffer, many others had more. The problem with CD-DA is that error correction is far from perfect, so you need to rip CD at least several times to get a perfect bitstream without any errors.

I had a combined mp3/CD player, the CD part had 45s shockproof the mp3 had 120s. I was suspicious about this because the size factor between CD and mp3(@128kbps popular at that time) was about 10:1. So that does not line up with the shockproof specs. Also buffering 45s of CD would need more than 6MB buffer, that was way too expensive for such a cheap player back in the early 2000s. So I figured they may compressed the music of some sort on the fly when using shockproof mode, although I've never seen it confirmed (and neither saw the 6MB memory chip sitting on the board)
 

Offline ebastler

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Re: A CD player with buffering
« Reply #7 on: February 27, 2019, 11:07:01 pm »
Guys, what’s wrong with your reading comprehension and sense of irony? OP knows that this technology is commonplace; the dodgy bit is that the company he linked to is selling it as a great new invention.

Hint: Keep an eye out fot those smiley icons...
 

Online wraper

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Re: A CD player with buffering
« Reply #8 on: February 27, 2019, 11:37:44 pm »
Guys, what’s wrong with your reading comprehension and sense of irony? OP knows that this technology is commonplace; the dodgy bit is that the company he linked to is selling it as a great new invention.

Hint: Keep an eye out fot those smiley icons...
Nothing wrong with comprehension. Just mentioning that their super solid state buffer is quite small even compared to much older and way cheaper devices.
 

Offline magic

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Re: A CD player with buffering
« Reply #9 on: February 28, 2019, 05:18:16 am »
It's even worse than "portable players do it".

Every single player on the market does it. They need to in order to perform error correction, which works on fixed size blocks of data. There is no way to correct for dirt and scratches without having already read several bytes in advance.

This product is bullshit because nobody simply streams bits from the photodiode straight to the DAC as they suggest. That wouldn't even be possible, given that
Quote from: wiki
The smallest entity in a CD is a channel-data frame, which consists of 33 bytes and contains six complete 16-bit stereo samples: 24 bytes for the audio (two bytes × two channels × six samples = 24 bytes), eight CIRC error-correction bytes, and one subcode byte. As described in the "Data encoding" section, after the EFM modulation the number of bits in a frame totals 588.
It's a nonsense written to mislead people who may be used to the way things work in vinyl and have no clue about digital technology.

Yes. Had to turn it off as the crazy people (AOC, genderbenders, flat earthers,...) gave false positives.
I've seen this phenomenon aptly described as
Quote
Poe’s Law singularity, at which the behavior of trolls and true believers becomes indistinguishable even to each other
 

Online David Hess

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Re: A CD player with buffering
« Reply #10 on: February 28, 2019, 04:08:29 pm »
I will not be happy until they use a sonically clean mercury delay line for buffering.
 

Offline Buriedcode

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Re: A CD player with buffering
« Reply #11 on: March 01, 2019, 02:23:50 am »
I will not be happy until they use a sonically clean mercury delay line for buffering.

That's more like the Dodgy technology we know and love!  But yeah, someone let the marketing team loose on really quite ancient (but still clever!) tech. 
 


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