DIY CD drive based on a computer CDROM

[Sergelisses]

I was able to find and tap into the 3 I2S signals from the controller chip of my CDROM and feeding it to a TwistedPearAudio DAC. Is this the best jitter performance I can get? What else can I do?


Tell me more ....
Where did you found the I2S signals ?

Serge

[glt]

Found an old CDROM (built in 2000). Took it apart and found the datasheet of the controller chip (a Windbond chip). Noticed that there are 3 audio out signals: LRCK, BCK and Data (These are not named I2S but are the same as the I2S signals). I have a Twistedpearaudio reclocker so I feed these 3 signals to the reclocker. Nothing. Then I change the settings to the reclocker to 16 bit input and right justified. I get music.

I tapped the 3 digital signals by soldering wires (cat5 wires) on vias. Then I rerouted them to the 4-wire analog plug in the back of the CDROM (first removing the analog connections to the board) and used the analog CDROM cable you find inside computers. This cable seems perfect since it has 3 signal wires and a ground shield.

The reclocker does not take the clock signal from the CDROM (In fact I did not look to see where it can be tapped. There is a 33.8688 clock but I'm not sure if this is the clock that can be fed to a DAC). The reclocker generates its own clock during the resampling and sends 24/194KHz to the DAC

[Sergelisses]

Today it's not easy to find the datasheet of the controller chip .


I think your solution to use directly the I2S signals is the best .



Serge

[glt]

In my experience, datasheets are easy to find. Search for the part number or Manufacturer plus part number.

[afhifi]

I have referred the feeder of the CDrom inserting to the 5V a couple of condensers from 22000uF, the controller now works well with many drives of various brands.
I don't know why without the condensers the 5V has a very strong trouble when the CDrom departs.

AFHIFI

[minivan]

Originally posted by glt
Found an old CDROM (built in 2000). Took it apart and found the datasheet of the controller chip (a Windbond chip). Noticed that there are 3 audio out signals: LRCK, BCK and Data (These are not named I2S but are the same as the I2S signals). I have a Twistedpearaudio reclocker so I feed these 3 signals to the reclocker. Nothing. Then I change the settings to the reclocker to 16 bit input and right justified. I get music.

I tapped the 3 digital signals by soldering wires (cat5 wires) on vias. Then I rerouted them to the 4-wire analog plug in the back of the CDROM (first removing the analog connections to the board) and used the analog CDROM cable you find inside computers. This cable seems perfect since it has 3 signal wires and a ground shield.

The reclocker does not take the clock signal from the CDROM (In fact I did not look to see where it can be tapped. There is a 33.8688 clock but I'm not sure if this is the clock that can be fed to a DAC). The reclocker generates its own clock during the resampling and sends 24/194KHz to the DAC

i have a 1999 sony cdrom, also has an windbond chip in there, part number is w29ee512p, goolge it up, it's a cmos flask memory chip, so how do u find out the i2s signal from it? ( the digital signal seem to come out from that chip ,but i have not use a multimeter to confirm yet)

[glt]

You have to identify the controller chip (in my case, the windbond chip is the cdrom controller chip), then the pin out will have signals with names similar to the ones from I2S. Some chips will not output I2S type, but directly SPDIF, so it depends on the controller chip. Its got to be one of the bigger asics in the board

[dearangelo]

Originally Posted by Kuei Yang Wang

Konnichiwa,



Well, if use async read and the ATA interface it should be fine, simply define an adjustable float relationship between master clock and output clock on S/P DIF.

HOWEVER, most decent external DAC's do not like "varispeed" too well, so it makes most sense with an I2S interface.

BTW, having a few % pitch is a good idea, as pitching music slightly flat of 440Hz can give a more "relaxing" perception and pitching it sharp will make it seem more "energetic" (no kidding - it is important to hit the right frequency too).

Sayonara

!! I have been reading thru, looking for a cd drive to player diy project to do...
excellent Idea the pitch thing...
so will you help me and save me the reading, direct me to the place where the fun starts, where the drive gets picked and dissected?
thank you

[gabrielbecheanu]

Hi
I have seen on EBay a cd-rom controller, it is interesting to make a cd transport but my big question is how accurate is the cd audio reading. We all know that when ripping a cd using EAC for best result is to configure the cd rom drive offset for best accuracy.
How we can make a cd rom using an external controller to read the audio cd format very well.
If this is possible I would like to make a cd transport for my CS4398 DAC
This is the controller iv seen on EBay.
CDROM controller DIY kits with BlueWhite LCD Display SE - eBay (item 260527580989 end time Mar-23-10 02:02:37 PDT)
Thanks

[dearangelo]

correct me if I am wrong, but accurate ripping has a value if you are reproducing the cd, and it is compared against the dbases, why would it be of any difference if it is a relative offset and not a referenced offset?
anyways, I ordered the same gadget for my plextor, I will live with it, it looks interesting to do a nice moding.
next step would be to get the cdpro2lf whatever, the works...
that should be a total...
regards
Angelo

ps perhaps this might be o a little help
http://forum.dbpoweramp.com/showthread.php?t=20731