Playstation as CD-player

[Mick_F]

Originally posted by back


that`s exactly the problem you need 10 ma for the lm317 to work and it did.nt work for me with 240R
then i changed to 82R and it worked.
the first time i took it from the datasheet and don`t know who made this mistake.
if you already have the transformer use it i attenuate it from 14.4v to 3.6v i just thought you didn`t bought it yet.
the lm 317 TO220 or not is capable of 1.5A

Very strange that they dont take more care of this. I am also quite sure that Nuuk has build a PSU for his Gainclone pre and has used 220R.....

Yes, I already have this transformer, I found two of them in the electronics garbage of my institute (where I also have a couple of nice cases from).

I might have overlooked something but I thought I found 3.4A as max current in the datasheet.... Anyway, 1.5 should work as well.

Mick

[jives11]

Thanks Mick,

I have implemented your mod, but have not yet tried it. I ended up using the bipolars with a 1.6K resistor to ground. The plastic caps I had were much too big. It was pretty straightforward to do.

I also :

1) removed the rubber pad on the top of the metal subchasis. This is the piece which rubs against a tab from the CD transport and prevents it 'bouncing' like a true suspended subchasis turntable.

2) I noticed that the main metal framework rings if struck, so stuck a piece of car damping material on the underside, roughly beneath where the CD transport sits , on the underside of the metal. I made sure I didn't block any holes, as I'm sure this metal also acts as a heatsink in part.

3) Removed the SMPS umbilical and carefully removed the connector from one end by prizing up the little plastic tabs a little. These are latches which once raised you can remove the cables. I did this and fitted better individual ferrite sleeves. I'll upload some pictures when I figure out how to resize the images on a mac.

[jives11]

Here is the Mick_F mod

[jives11]

Here is where I put the damping material

[jives11]

here is the new ferrite 'hydra' umbilical

[Mick_F]

Nice work, Jives. So you really dared to drill a hole into the board
Please let us know what you think about the sound!


I also just come from the workshop. I tried to improve the laser adjustment according to the voltage values recently provided by dommi.
Well, I found that setting the laser intensity to a value of 11.7mV indeed brought some improvement. I could read a CD which did not work before. Then I tried to set the bias and gain to 1.54 and 1.75V, respectively. That did not work at all. I could set the bias to 1.54V but I was not able to lower the gain as low as 1.75V. As soon as I reached a value of 1.80V or so, the laser started to move up and down all the time.

Dommi, are you sure about these values?

Mick

[DragonMaster]

Hi, I tried Mick's output stage mod (without the caps...) on Christmas. (Was trying my new Dremel)

Well... it was late once I found why the right channel wouldn't work so I can't really tell anything about the sound. I think it sounds better that way compared to passing thru a resistor and a cap to ground.

Mick, you can search on PlayStation DIY repair sites and you don't always see the same voltage.

Maybe 1.75 and 1.85 are OK because mine was already set to these when I got it.

I don't know if the wrong voltage could damage the laser with time.

[back]

Originally posted by Mick_F



Very strange that they dont take more care of this. I am also quite sure that Nuuk has build a PSU for his Gainclone pre and has used 220R.....

Yes, I already have this transformer, I found two of them in the electronics garbage of my institute (where I also have a couple of nice cases from).

I might have overlooked something but I thought I found 3.4A as max current in the datasheet.... Anyway, 1.5 should work as well.

Mick

the datasheet says 1.5A.

you can try 240R to see for yourself.
no damage done it just don`t work

[DragonMaster]

the datasheet says 1.5A.

It always depends of the mfg and exact product number. I have a 1.5A 7805 while they are normally 1A

[Nanook]

just to clarify the comments regarding blue LEDs and the notion of blue light "absorbing" :

"there is a blue laser which floods the underside of the CD in blue light which actually adds optical noise. As Yves himself says " the optical noise created by the blue laser (known as "stochastic resonance".......a great name for a heavy metal band in my humble opinion!) actually permits the recovery of some information whose energy was not sufficient to drive a 0 to a 1 or the other way around". And remember with digital all bits of information are either a 0 or a 1. By adding some noise(optical only) you paradoxically get more information back. Yves feels that with his unique blue laser he has created a CD player that regains the emotional content usually missing with digital reproduction components, and gives a sound more akin to analog tape."
from
Audiophile Audition , January '02

This is the same principle of light emitting "mats" for cd players., such as the Audio Prism CD Blacklight.

still tinkering myself:-)