DIY CD drive based on a computer CDROM

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#281
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
Click to expand...

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
 
#284
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
 
#285
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..
Click to expand...

???

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
 
#287
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
 

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#290
hifi said:
No.. I2S comes in four different shapes

Normal
Sony / BB / jap
Left justifed
Right justifed


/ Mikael
Click to expand...


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.
 
#294
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.

😎
 
#297
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...
 
#300
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
Click to expand...

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
 
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