Ill use yours (because i only have opa627s) which i already built, just need to insert opamps and make psu for it..
Maybe it really is pcm1710, because somewhere on the process, i connected it to 12v by accident
Ill try what you emiled me with reset button on gnd and after 2 secs on +3.3v and if that wont work ill change pcm.
Maybe it really is pcm1710, because somewhere on the process, i connected it to 12v by accident
Ill try what you emiled me with reset button on gnd and after 2 secs on +3.3v and if that wont work ill change pcm.
You must have oscillations in the power supplies.
What regulators are you using?
If you have 780x then connect some pF capacitors directly on the pins and put a resistor of 10K from the output to gnd.
Put pF caps on the supply pins of each IC (Vcc and Gnd).
Try to gnd all the input pins that remain unconnected in 74hcu04.
I think that SP/DIF is 0.5Vp-p on 75Ohm load.
Haven't check it with oscilloscope though on cd-roms output.
What regulators are you using?
If you have 780x then connect some pF capacitors directly on the pins and put a resistor of 10K from the output to gnd.
Put pF caps on the supply pins of each IC (Vcc and Gnd).
Try to gnd all the input pins that remain unconnected in 74hcu04.
I think that SP/DIF is 0.5Vp-p on 75Ohm load.
Haven't check it with oscilloscope though on cd-roms output.
I used 2x 12v /6w transformer and bridge rectifier than caps and i get +-16v which goes directly to opamps - if heres the problem how do i get rid of oscillations here?
I used only one 7805 for whole dac, with two dides before dir 1703 to get 3,6V for it.
I will add good separate regulators for each part of the circuit tomorrow..
Can you tell me which regulators are good choices?
I have a lot of lm317s if they are good enough.. but how do i accurately set the output voltages when using them?
I used 68 ohm resistor which i had on hand instead of 75, on input.
I will gnd unused inputs (i used 74HC04 (MC74HC04AN is written on the chip) and not HCU).
I used only one 7805 for whole dac, with two dides before dir 1703 to get 3,6V for it.
I will add good separate regulators for each part of the circuit tomorrow..
Can you tell me which regulators are good choices?
I have a lot of lm317s if they are good enough.. but how do i accurately set the output voltages when using them?
I used 68 ohm resistor which i had on hand instead of 75, on input.
I will gnd unused inputs (i used 74HC04 (MC74HC04AN is written on the chip) and not HCU).
Re: how do you disable Windows media player
Check the following
http://www.microsoft.com/hwdev/archive/devdes/cddigital.asp
I will try to locate for win95
Regards
makisb
yves said:
Check the following
http://www.microsoft.com/hwdev/archive/devdes/cddigital.asp
I will try to locate for win95
Regards
makisb
makisb said:
S/PDIF standard is 0.5..1V. But many computer devices uses TTL level S/PDIF, almost all CD-ROMs. All Toslink modules also need +5V S/PDIF.
Read here (there is also a lot of useful circuits): http://www.epanorama.net/documents/audio/spdif.html
skaara
I'm busy working on a similar project so..
3 Points:
1) STOP shorting out pins!!!! You can be glad you don't live in ZA where it takes 2 - 8 weeks to get replacement parts. Triple check everything, visually & with an oscilloscope / multimeter before applying power.I know it's a pain, especially when one wants to get the newly built toy going ASAP, but it pays off in the long run when diagnosing problems.
2) Most cdroms output a 5v TTL spdif signal, while those crystal receivers are pretty tolerant, there's no reason to not convert this signal before it gets to an (in my experience) expensive device.
3) Use an HCU 74 series chip, the non U units are buffered, and have reported issues, specifically with oscillation.
Have fun
Jan
I'm busy working on a similar project so..
3 Points:
1) STOP shorting out pins!!!! You can be glad you don't live in ZA where it takes 2 - 8 weeks to get replacement parts. Triple check everything, visually & with an oscilloscope / multimeter before applying power.I know it's a pain, especially when one wants to get the newly built toy going ASAP, but it pays off in the long run when diagnosing problems.
2) Most cdroms output a 5v TTL spdif signal, while those crystal receivers are pretty tolerant, there's no reason to not convert this signal before it gets to an (in my experience) expensive device.
3) Use an HCU 74 series chip, the non U units are buffered, and have reported issues, specifically with oscillation.
Have fun
Jan
The mentioned page, http://www.epanorama.net/documents/audio/spdif.html, has circuits for converting TTL to/from standard level S/PDIF and also to/from AES/EBU.
This is an old thread but I think the subject is similar. I need some help advice.
I am trying to use a Creative 2X CDROM (model CD220E) as a CD transport to feed my CS8412/TDA1543 NOS DAC. This CDROM is only 2X speed so it's operation is quiet and it needs only a 5V PSU (I have constructed a linear regulated PSU) and it was very cheap- free.
With the CDROM's digital out connected to the DAC input, but with the CD tray empty, there is a harsh static sound that goes away when I press the play button. (This unit has play/skip and stop/eject buttons).
The same sounds occurs when I press the skip button. That is, the sound is present during the time required to skip to the next track. The sound also returns when I press the stop/eject button
The sound of the CDROM transport during actual playing of music is excellent, even better than my Rotel RCD965BX which I have been using as a transport of the NOS DAC. No static, only music.
Can anyone suggest a solution, or even name the problem? Do I need to consider a more modern CDROM?
Joe.
I am trying to use a Creative 2X CDROM (model CD220E) as a CD transport to feed my CS8412/TDA1543 NOS DAC. This CDROM is only 2X speed so it's operation is quiet and it needs only a 5V PSU (I have constructed a linear regulated PSU) and it was very cheap- free.
With the CDROM's digital out connected to the DAC input, but with the CD tray empty, there is a harsh static sound that goes away when I press the play button. (This unit has play/skip and stop/eject buttons).
The same sounds occurs when I press the skip button. That is, the sound is present during the time required to skip to the next track. The sound also returns when I press the stop/eject button
The sound of the CDROM transport during actual playing of music is excellent, even better than my Rotel RCD965BX which I have been using as a transport of the NOS DAC. No static, only music.
Can anyone suggest a solution, or even name the problem? Do I need to consider a more modern CDROM?
Joe.
Further to my post yesterday about noise on CDROM digital output.
I can add that the harsh static sound seems to be synchronised with the CDROM motor. That, is, as the motor spins up to speed, the intensity of the noise increases. It then disappears when I press the play button, but reappears when I press the eject button.
Any ideas?
Joe
I can add that the harsh static sound seems to be synchronised with the CDROM motor. That, is, as the motor spins up to speed, the intensity of the noise increases. It then disappears when I press the play button, but reappears when I press the eject button.
Any ideas?
Joe
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