DIY CD drive based on a computer CDROM

fedde · 2003-09-15 3:26 pm

Re: Clock division for CD ROM transport

Oli said:
I Picked up a cheap NEC CDR500 CD ROM drive at the weekend (SCSI). I have already taken it to pieces- a nice aluminium cast assembly like a CD-PRO mechanism. Unfortunately I was not too observant and there is no S/PDIF out! Looking on the board I have found a TDA1545A (with I2S bus). I wish to use the I2S, together with a CS8402A to provide me with a nice S/PDIF output so I can use with a variety of equipment (I know it is not the ultimate!) Of course I am going to reclock the transport. Currently the clock operates at 384 x fs (44100). However the Crystal Semiconductor transmitter only operates at 256 x fs

That is very interesting!!! I would say solder the TDA1545A out of the player. Build an external TDA1545 (or TDA1541/1543) DAC with good supply. Throw a good 16.9 Mhz clock circuit in (like Guido Tent's clock, very compact). Reclock the I2S with the clock circuit (near the DAC) and lead the clock signal also into the CD-rom unit. That could be a killer transport+DAC combo!!!

I should try to get such a player! Does it have play/stop controls !?

Fedde

guido · 2003-09-15 4:43 pm

TDA1543A is not i2s, it's japanese standard.
GuidoB

fedde · 2003-09-15 5:15 pm

So ???

We were talking about the TDA1545A. Is that chip also in Japanese format !?

Fedde

hifi · 2003-09-15 5:20 pm

It probobly is, atleast the Nec 6XE uses CXD2510Q it puts out I2s in japanese form...althogh it is quite possibly to use logic to convert it to "regular" spdif

but why would you want to encode the i2s to spdif isnt spdif already availible from the chipset in the player?...if so just use a 74vhc04 to resquare it and add some nice digital output driver..

http://www.diymania.net/pass/project/transport.htm

i just saw this transport...im thinking about rebuild my 6xe into something like that!

/micke

fedde · 2003-09-15 5:32 pm

hifi said:
It probobly is, atleast the Nec 6XE uses CXD2510Q it puts out I2s in japanese form...althogh it is quite possibly to use logic to convert it to "regular" spdif

but why would you want to encode the i2s to spdif isnt spdif already availible from the chipset in the player?...if so just use a 74vhc04 to resquare it and add some nice digital output driver..

???

I don't want SP/DIF, I just want normal I2S output for TDA1541-1545...
If I build a custom transport, I use a custom interface

Fedde

fedde · 2003-09-15 5:35 pm

Hmmm, you are right the TDA1545 also uses the japanese format

(I wonder why they didn't name it TDA1545J...)

http://www.semiconductors.philips.com/pip/TDA1545AT.html

Fedde

hifi · 2003-09-15 5:44 pm

Then you would need to use some glue logic to make a translation between the i2s formats, not a big deal though...

btw here is the Spdif output i made for my 6XE it will be fun to se how it performs

/ Micke

rfbrw · 2003-09-15 8:53 pm

hifi said:
I2s in japanese form

There is no such animal. It is either I2S or not.

ray.

hifi · 2003-09-15 10:16 pm

No.. I2S comes in four different shapes

Normal
Sony / BB / jap
Left justifed
Right justifed

/ Mikael

rfbrw · 2003-09-15 10:31 pm

hifi said:
No.. I2S comes in four different shapes

Normal
Sony / BB / jap
Left justifed
Right justifed

/ Mikael

Complete and utter rubbish. I2S, Inter IC Soundbus is a proprietary Philips format. While it might prove difficult to get hold of the original ELCOMA article introducing I2S, you can still get the I2S bus standard from the Philips website. Even a simple google search will produce it.

http://www.semiconductors.philips.com/acrobat/various/I2SBUS.pdf

ray.

guido · 2003-09-15 11:21 pm

what i meant was use the 1543a (or the current dac). i2s wont work without more effort.

But is it already oversampled before it goes to the dac???? if it is, spdif migh not be feasible (dont know) and using 1543a wont be non OS. Check the clockfreq!

GuidoB

bknauss · 2003-09-17 3:44 am

This is just my 2 cents, but I would prefer that we keep this as a PC CD player used as a standalone CD player instead of a PC CD player used in an HTPC. I personally think it kills all the fun of the DIY

Matttcattt · 2003-09-17 8:10 am

i want to make a DAC to convert the SPDIF output of my CD-ROM drive. unfortunatly i have no idea were to start.

i was thinking of reprodinging MWP's design, here, posted here. if i get permission.

is there a simpler DAC i could make using TI chips?

how do i connect the DAC to the CD-ROM drive?

Lupulroz · 2003-09-17 8:26 pm

I made some experiences with an older Sony drive - I could extract from it controls and digital output (in Sony format). The initial setup was Sony CDROM - glue logic - AD1865N-K - my custom I/V stage. The sound was sterile and uninvolving, missing resolution and tonal balance.
Today I removed the clock resonator from the cdrom-board and I injected 33,86 MHz from a PLL clock source made with PLL1705. I exepected an improvement... but magic happened.
All bad things are gone - and replaced with that nice quality that you want to listen more and more.
Of course the setup can be improved - master clock directly to DAC comes next.
So I had the proof today: CDROM can sound great if properly set.

genome · 2003-09-18 4:15 pm

Hi Lupulroz,
I had trouble to get digital signal out from the SONY CDROM. Would you please share me with your design to get the thing done.
Will even more appreciate if you can share with the clock PLL circuit.

Thanks

Lupulroz · 2003-09-18 6:31 pm

I used a Sony CDR-272 from 1996. If you have the same model I can help you with the signals. For PLL clock check PLL1705 datasheet at Texas Instruments website.

stelios · 2003-09-19 12:02 pm

C compilers for the PIC Micro

Just came across these links:

C Compilers for the PIC Micro
C for PIC Microcontrollers, CD-ROM product
http://www.matrixmultimedia.co.uk
PCB compiler (for 12-bits PICs), PCM compiler (for 14-bits PICs), PCH compiler (for 18-bits PICs) and PCW(H) compiler (Windows version)
http://www.ccsinfo.com/picc.shtml
PCW demo version (1 k):
http://www.ccsinfo.com/demo.htm
C2C compiler:
http://www.picant.com/c2c/c.html
ConTEXT programming editor
http://www.fixedsys.com/context/

Might be of interest to some...

Matttcattt · 2003-09-19 5:12 pm

sorry about my ignarance, but where is the SPDIF output on a CD-ROM drive? is it a seperate socket, or is it in the IDE connection?

fedde · 2003-09-19 5:47 pm

It is a separate connector. It has 2 pins and not all drives have it!

BTW: very nice forum Matthew, thank you for reminding me

Fedde

jkeny · 2003-09-20 12:50 am

Sony CD-Rom

I used a Sony CDR-272 from 1996. If you have the same model I can help you with the signals. For PLL clock check PLL1705 datasheet at Texas Instruments website

Lupulroz
Any experience with Sony CDU55E - rated as good cd rom in its day - but only audio out connector - no dig out. I'm looking to put it to good use

John

DIY CD drive based on a computer CDROM

Member

Member

Member

Member

Member

Member

Member

Attachments

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Banned