Anyone heard of painting CD tray Mod ?

No it didn't. There is a lot of processing between the read head and the DAC. The read head is an analogue process, and backscattered light might possibly slightly degrade the eye in the data slicer. But that would only potentially cause bit read errors, which will be addressed by the error detection and correction circuits. The data passed to the DAC is digital. If the ECC can't correct the bit errors, it would mute the sample. You'd notice such muting. Backscatter might possibly slightly degrade the servo tracking loops, but the process by which data is passed to the DAC is driven from the DAC end (and the CD drive locks the read servo to that clock). There's a FIFO buffer in the way to sort out read speed variations due to servo 'wobble' that might be caused by backscatter, as well as the deinterleaving buffer. Again, if the servo loops are so badly affected that the buffering is inadequate, you'd notice it.

And, when I say 'notice it', i'm not talking 'a more airy feel'; I'm talking gaps, pops & stuttering.

Backscatter will not 'confuse the d/a'.
Interesting rebuttal, expectation bias then?
 
Any valid reason for doing so ?

There's actually a bit of science behind it. I'm sure all you scientific types will have noticed that the colors chosen are all within the spectrum used by the optical disc's laser reader. Coloring the tray can improve the accuracy of the reader's focus and reducing error count by eliminating conflicting spectra that are either too reflective or not reflective enough.

Data on using different colors on the same tray is still out, but speculation is that this schema allows the laser to re-sample a multitude of primaries if needed to reduce error count for difficult passages or inferior pressings, Painting these colors by thirds optimizes the read time based on the turntable revolutions at redbook speeds, keeping the re-samples needed to the bare minimum.

Some have experimented with paper inserts that can supposedly further optimization read accuracy using different colors based on manufacturer's and consumers real world results, optical drive brands, disc condition and age, but the jury's still out on this.

(see note below)


Thanks...
 
That would be my suggestion, yes.
Expectation bias, in my case, tends toward disappointment rather than re-enforcement.
Regardless, are there 'enhancements' or modifications to CD playback you would consider technically justifiable?
 
I have found that painting my CD tray in festive colors makes the music sound less drab.

At this time of year, I usually go with the traditional Christmas holiday colors as it makes my music sound more, well, traditional.
I spray mine with some of that pine tree scent we got from Bath & Body Works a decade ago. My system does sound kind of wooden now, however...
 
dudes, there's no light inside a CD tray when closed.

the real reason is to color match your mug when it's used as a cup holder.
 
Regardless, are there 'enhancements' or modifications to CD playback you would consider technically justifiable?

Yes, but in the design of the player. As with external DACs, the point in the system where we really need to start taking care is from the digital interface onwards; getting the data off the disc (or rendering digital files to PCM) should not impact on the audio quality, provided the error recovery isn't over-stressed to the point of failure.

So, we need to pay attention to the following:

Data interface to the DAC (to prevent broadband digital noise getting to the DAC). This includes the PCM sample stream and any SPI control stream.
Separate DAC power supplies (at least four separate, low noise supplies: data section, reference voltage, analogue output, clock oscillator & DAC clock input). 'Separation' can come from individual filtering & regulation.
Choice of DAC, including upsampling and digital filtering.
Output filtering & buffering design & implementation.
[edit: oh yes: PCB layout; again, to keep digital noise away from the analogue]

Essentially: keep the digital processing noise away from the analogue processing; provide a very clean clock to the DAC to minimise jitter, and use good quality analogue components in the output buffer/filter stage.
 
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I took note of this additional mod he performed:

"Next I wrapped some tourmaline crystals around the ac interior connection."

I recommend this mod as Maine is a source of tourmaline. By using raspberry pink-red as well as minty green crystals one will help our economy. Thank you. ;-)
I grew up in Maine. My Avatar is from a trip this past summer. Nice little pond in the Bridgton area.
 
Yes, but in the design of the player. As with external DACs, the point in the system where we really need to start taking care is from the digital interface onwards; getting the data off the disc (or rendering digital files to PCM) should not impact on the audio quality, provided the error recovery isn't over-stressed to the point of failure.

So, we need to pay attention to the following:

Data interface to the DAC (to prevent broadband digital noise getting to the DAC). This includes the PCM sample stream and any SPI control stream.
Separate DAC power supplies (at least four separate, low noise supplies: data section, reference voltage, analogue output, clock). 'Separation' can come from individual filtering & regulation.
Choice of DAC, including upsampling and digital filtering.
Output filtering & buffering design & implementation.

Essentially: keep the digital processing noise away from the analogue processing; provide a very clean clock to the DAC to minimise jitter, and use good quality analogue components in the output buffer/filter stage.
How much jitter could the hub motor contribute?
 
How much jitter could the hub motor contribute?

That's still part of the disc reading process, and would result in jitter in the data recovery timing off the read head, reducing the data slicer timing margins. It should not get to the DAC in a well-designed player; remember the DAC clock feeds the read mechanism, not the other way round.
 
I took note of this additional mod he performed:

"Next I wrapped some tourmaline crystals around the ac interior connection."

I recommend this mod as Maine is a source of tourmaline. By using raspberry pink-red as well as minty green crystals one will help our economy. Thank you. ;-)

Here's the "science" about that tweak, from https://www.energymuse.com/blacktourmaline-meaning. Apparently he thinks that works as some kind of power line filter :crazy:

"Get your chakras sparkling clean with the Black Tourmaline crystal, a big-time energy purifier in the world of healing crystals. Like a daily disinfectant for the soul, the Black Tourmaline crystal cleanses the aura of icky thought patterns keeping you up at night. Wherever you happen to be on your spiritual journey, Black Tourmaline is an excellent crystal for everyone because it's the bodyguard stone that provides protection and elimination of negative energy. Wear it as jewelry, keep it in your car, place it all over the house, near computers. Seriously, just put it everywhere because this all-around energy cleanser is a must-have for every gemstone collection. "

I'll have to try that, since I thought my system's chakras were getting a bit dingy :D
 
That's still part of the disc reading process, and would result in jitter in the data recovery timing off the read head, reducing the data slicer timing margins. It should not get to the DAC in a well-designed player; remember the DAC clock feeds the read mechanism, not the other way round.
I ask because of the trend to low torque hub motors, besides being less costly allow the flywheel effect to smooth things there, with gentle speed control applied. Agressive speed correction on a higher torque motor to me would be a source of jitter.
 
Agressive speed correction on a higher torque motor to me would be a source of jitter.

Just because you have a high torque motor, it doesn't mean you have to use that torque in 'lumps'. It's all down to the design of the control loop. You can have the same loop gain with a high torque motor as you can with a low torque motor; you just juggle the various gain stages. A high torque motor allows you to have a higher loop bandwidth, and better step response. But both of those need to be treated with care to ensure the control loop remains stable.

I think your cost argument is probably what drove the change...
 
its the crystals that made the changes .
Black Tourmaline is a protective stone which repels and blocks negative energies and psychic attack. ... Black Tourmaline will cleanse, purify, and transform dense energy into a lighter vibration. A popular metaphysical stone, Black Tourmaline is also great for grounding.
 
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