cd rom digital output

[skaara]

Is computer cdrom digital output suitable for dac? Does it have to be manually enabled or its on every time i play a cd?

I built dac from this ( http://diyaudio.com/forums/showthread.php?s=&threadid=6391&perpage=15&pagenumber=2 ) thread, page two - dac6.zip but when i connect it to digital out, nothing changes anywhere.

I emailed MakisB, who made this dac, he said he used kwak clock, Elso can you email schematics and pcb layout (if you have it) to me please?
Is clock needed for this dac to work and if it is - where do i connect it?


Sorry for asking dumb questions, but Im new to digital so more questions may arise

 

[skaara]

Now i measured my cdrom digital out and saw that nothing camed out so i used other cdrom and measured again, now i see something, but at the output of the dac is only hf, no music.
Is it possible that pcm1710 is dead?

I used 16,000 mhz crstal here, is anything wrong with this?

 

[cowanrg]

i would actually like to hear an answer for this, so, im bumping it. i think this could make a good project. from what ive read, cd-roms are great for a easy transport.

 

[mekanoplastik]

hey Cowanrg check this out....

http://users.bigpond.net.au/redgumaudio/review18_hthifi.html

it does not look too dificult to builld and the cdrom (cd552e 52x infra) is about 30$ new...maybe it is a good idea to get a simple dac and a power supply for a cdrom...


m.

 

[Circlotron]

Yeah, I like this idea too. I always wanted to do something with the digital output . One thing I would like to suggest as far as a project is concerned is, with a normal audio CD player the laser only makes 1 pass over the data and the error correction does the best it can with what it gets. Now with a CDROM drive you just can't afford errors so the drive reads and re-reads the track until it gets it right. With 52x CDROM drives available now, it would seem a good idea to use all that extra speed to read a section of audio track 20 or 30 times before moving on to the next bit, to make sure it was as right as it could be. Easy to say. Hard to do?

 

[skaara]

Is then cdrom digital out suitable for directly feeding the dac (in the link i posted above)?

 

[tone]

cdrom

hi ppl,
i have tried using faster cdrom, way to much vibration..at the end i switch to 24x cdrom..almost no vibration at all.. so i would recommand using lower speed cdrom..Pls build a good dedicate power supply for the cdrom..cdrom eat quite a current!! im using a diy non-oveersampling CS8412, TDA1543..with no problem..just plug in the cdrom digitsl output to the input of the dac...VOILA!!

rgds,
tone

 

[skaara]

Ok, so the problem is not in the cd digital out.. I looked in datasheet of dir1703 and there is a list of crystals, and 16,000mhz i used (i couldnt get 16.9344mhz one, so i bought the nearest value..) its not on it, is that the problem?

 

[tone]

try borrow a dac and then plug it in...if it works ..then it is yur dac that are not complatible..maybe the crystal freq?>.not sure..sorry.

 

[skaara]

I dont know anyone who have a separate dac component..

 

[skaara]

I found the crystal in my cd player i opened, installed it in this dac and now i hear some music at the output of the dac, but it is quiet (1sec) than music (2sec) than quiet(0.5sec) than music (1 sec) and so on randomly.. Anyone knows what could this be?

 

[makisb]

Digtl out

Beware of Windows Media Player!!
It will disable cd-rom's digital out by default.
Use winamp instead...

This is what i did (in win98, no xp) and the circuit works fine.

You do not have to put a special clock to DIR1703 to get it work.
It will work with a crystal just fine.


Regards
Makisb

 

[skaara]

I did that, but the music on output of pcm1710 isnt playing smoothl, it stops than plays and so on, its like music is coming in "packets"..
Is something wrong with the clock?

 

[makisb]

Try to reset DIR1703 2-3 seconds after you apply power.
I will try it with a crystall of 16,000MHz tonight and see...
Give it a shot with 256fs (11.2896MHz).

Regards
makisb

 

[skaara]

I found the 16,9344mhz in my cdplayer and tooked it out and used it in this circuit. With 16,000 mhz i couldnt hear any music at all. This problem is with 16,9344mhz crystal.

 

[makisb]

Do you hear from the output of the filter?
What op amp have you used?

 

[skaara]

I hear this directly from the dac output (on dac output pin) when i connect 16ohm speaker. I will use opa627s.

 

[makisb]

From PCM1710 DIRECTLY to speaker?
Try with an amplifier,or an op amp but
use a RC lowpass filter before .
Otherwise your amp ( and op amp) will oscillate.

 

[skaara]

Yes, to 16ohm headphones.. When i use scope (without speaker connected( to see whats coming out its just straight line, because music pulses are ver short and i see only glitching
I will use everything what is shown in your schematic.

 

[makisb]

PCM1710 will drive a 5K load
from the datasheet...