Playstation as CD-player

[Mick_F]

Afaik those people suggesting the use of blue LEDs say that the chamber containing the laser and the disk must be light tight.

No cool look .......

Did you test the modified PS already?

Mick

[Nanook]

I was merely pointing people to the article on Blue LEDs and their use in YBA's cd players. "Flooding" the cd player with a laser does not make sense, why would one build a laser to diverge the very light that is created? An LED is an easy to implement "flood" of near coherent light. As to whether one may hear a difference or not, who cares? If your experience suggests that there is no difference, then in the current state of build of your player, then there is no difference. (AB testing is full of examples that can be shot down....and is another can of worms to open up). I suspect that if the enclosure is not "light tight" , or has an exposed transport then the differences, if any, may be nonexistent.

My thoughts are to add light that is not the original wavelength of the laser, and to introduce light"noise". The amplitude of the noise may help the error correction circuitry to differentiate between signal and noise and make better , more consistant corrections (I guess I think of it as optical "dithering").

What have the experiences of people here using the Audio Prism Blacklight (or the White Mirror "La Musica" CD edition mat ) or similar? I don't use one, and some of the arguements are dampening the cd disc itself as well as phosphorous illumination..

Just a few thoughts.

[jives11]

Originally posted by Mick_F
Afaik those people suggesting the use of blue LEDs say that the chamber containing the laser and the disk must be light tight.

No cool look .......

Did you test the modified PS already?

Mick

sound is good but only on one channel. Looks like I may have made the same mistake as Dragonmaster. I'll revisit tomorrow

[mrskinny]

I did the output stage mod on one of my players also (with caps). I ran into the same problem with the right channel not working after the mod. I had checked everything over quite carefully as I was doing the job, and couldn't understand why the one channel wouldn't work. I took the player apart again and checked everything over, but couldn't find anything wrong... As it turned out the problem is the RCA connector itself. Unlike the connector for the left channel the one for the right is made in two pieces- one half is soldered to the pad where the new wiring connects, while the other half sloders to a pad beside this,which connected to the small SMD capacitor that was removed (next to the "block" on top of the board). The two halves of the right RCA were connected - until the cable was installed. The center pin on the cable pushed the two halves apart, and there was a connection only on on half of the RCA socket now- of course on the half that goes to the little SMD capacitor, which now connects to nothing. I soldered a jumper wire between the two pads on the bottom of the board, and it's been working fine for the past four days now.

[Mick_F]

Thanks for that answer, Mr. Skinny. Now I understand why I did not have this problem. The photos were taken on my fried trial board. When I did the mod on my current player, I used the other solder tag because the cable distances were more symmetric with respect to the hole position in that board.

Well, the trouble seems to be solved now and I will make a note on my website accordingly.

I also start to understand now what the function of the strange "thing" is. If no plug is inserted into the RCA jack of the right channel, there is a short between the two solder tags. This short is seen by the "thing" (and the desoldered capacitor may belong to its perifery) and then it leads a mixed L+R signal to the left RCA jack.

Mick

[Mick_F]

Originally posted by Nanook

My thoughts are to add light that is not the original wavelength of the laser, and to introduce light"noise". The amplitude of the noise may help the error correction circuitry to differentiate between signal and noise and make better , more consistant corrections (I guess I think of it as optical "dithering").

Well, you say you want to add noise in order to help the circuitry to distinguish between signal and noise. Seems to be better to get rid of as much as possible noise right from the start

From a physics point of view, there will be no interaction between the light of different color (i.e. frequency). If the detector has an input filter set to the laser frequency, there will be no change at all. IF you want to add some intensity in the spectral range of the laser, you should let some white light in, in which the correct color is present (you could simply leave the door open). But even then, it is questionable if there is any positive effect.

Adding mass to the CD by putting a rigid mat on it may have influence on the mechanical behaviour of the spinning system and this may have some sonically positive effects. One has to be careful, however, as the whole assembly is designed for the average mass of a CD, and adding to much weigth may reduce the lifetime of the motor.

Btw, your nick (and signature) refer to one of my favourite pieces of music. FZ would have celebrated his 65th birthday last week......

Mick

[jives11]

Originally posted by mrskinny
I did the output stage mod on one of my players also (with caps). I ran into the same problem with the right channel not working after the mod. I had checked everything over quite carefully as I was doing the job, and couldn't understand why the one channel wouldn't work. I took the player apart again and checked everything over, but couldn't find anything wrong... As it turned out the problem is the RCA connector itself. Unlike the connector for the left channel the one for the right is made in two pieces- one half is soldered to the pad where the new wiring connects, while the other half sloders to a pad beside this,which connected to the small SMD capacitor that was removed (next to the "block" on top of the board). The two halves of the right RCA were connected - until the cable was installed. The center pin on the cable pushed the two halves apart, and there was a connection only on on half of the RCA socket now- of course on the half that goes to the little SMD capacitor, which now connects to nothing. I soldered a jumper wire between the two pads on the bottom of the board, and it's been working fine for the past four days now.

Thanks mrskinny, that was it ! I fitted a jumper and now I have both channels working. Too early to tell, but I can tell that the rolloff caps are gone ! A brighter sound.

[jives11]

Originally posted by Mick_F




Adding mass to the CD by putting a rigid mat on it may have influence on the mechanical behaviour of the spinning system and this may have some sonically positive effects. One has to be careful, however, as the whole assembly is designed for the average mass of a CD, and adding to much weigth may reduce the lifetime of the motor.

Hi Mick,

I have a little evidence that increasing the mass makes a difference. In my kitchen I have a Tivoli Model One mono radio. On top of this I have a circa 1987 Sony Discman Mk 1. The discman connects to the tivoli aux input and the whole thing sounds surprisingly good. However as the discman sits ontop of what is a speaker box, it can mistrack during loud passages due to vibration. I then dug out an old rubber CD mat that Meridian included with the original MCD (a friend gave it to me). The player will track now, but i can remove the mat and it skips all over. I always use it.

Originally posted by Mick_F

Btw, your nick (and signature) refer to one of my favourite pieces of music. FZ would have celebrated his 65th birthday last week......

Mick

Or is it Mr Skin from 'Spirit' - another fine Band

[Mick_F]

Jives, I am happy to hear that the mod has brought some improvement.

Dommi, I have once again checked the alignment stuff. This time I have set the laser intensity to 11.4 mV, reduced the bias to 1.54 V and still I cannot reduce the gain below about 1.82 V. Below that value the laser seems to run up and down continuously.

After some experimenting, I found the optimum values (at least for my setup): Laser intensity 11.4 mV, bias 1.70 V, gain 1.82 V. With these settings, I can read almost all my CDs that seemed to make problems before. (Those which made problems are all Audio CD ROMs, I have not found any commercial CDs that did not run).

Originally posted by jives11

Hi Mick,

I have a little evidence that increasing the mass makes a difference. In my kitchen I have a Tivoli Model One mono radio. On top of this I have a circa 1987 Sony Discman Mk 1. The discman connects to the tivoli aux input and the whole thing sounds surprisingly good. However as the discman sits ontop of what is a speaker box, it can mistrack during loud passages due to vibration. I then dug out an old rubber CD mat that Meridian included with the original MCD (a friend gave it to me). The player will track now, but i can remove the mat and it skips all over. I always use it.

Well, as I said, changing the mass may change the mechanical behaviour of the system. And in your case this has a directly observable positive effect

Btw. I also have a Tivoli Model One in my kitchen.....



Mick

[Mick_F]

I made several updates to my website.

Cheers,
Mick