Audible squeaking artifact in custom player

[JimmyBarnes]

I built a custom movie player PC - nothing special MSI KM2M mainboard/ Duron 1000/ 256 MB SDRAM/ 10 GB HD/64 MB / GeForce4 MX 440 graphics 64 MB / LiteOn DVD-ROM16x/Windows 98SE.

Works fine but I added some RF 443 MHz wireless headphones so I could watch movies late at night. They work fine except I get a soft squeaking noise in sync with the DVD-ROM light's flashing. Happens with a wide variety if not all movies tried. Not noticeable from the TV speakers unless you put your ear right up in a very low background noise scene.

Turned off DMA for the DVD-ROM but this did not fix the prob tho it did fix another "pitter-patter" audible artifact. Other Device Manager setting for the drive did not make any difference.

Wondering if anyone else has encountered this and managed to fix it?

thanx
JB

[Leak]

Originally posted by JimmyBarnes
Wondering if anyone else has encountered this and managed to fix it?


Sounds like a hardware problem to me (the IDE bus somehow affecting the audio signal path, most probably after the digital-to-analog conversion); if you're using onboard audio I don't think you can do much but putting in a sound card (or perhaps re-routing the IDE cables), and if you already have one try moving it to a different PCI slot. Using an USB audio device might also help, as the DAC will happen outside of your PC case then.

np: Kow Otani - Blight (Haibane Renmei OST Hanenone)

[JimmyBarnes]

Found the quick fix was to remove the CD audio cable linking DVd-ROM to mainboard. Then both the squeak and pitter-patter artifacts ceased. Means I can't play audio CDs in the unit but I never do that anyway.

For a few brief minutes the problem went away (CD-audio cable present, DVD-ROM DMA enabled), but then it came back and I have never been able to get rid of it since, apart from doing the above.

I briefly replaced the LiteOn DVD-ROM with an Hitachi one and it did not have the problem so the latter may well reside in the LiteON DVD-ROM. Pity, as it reads DVD-R whereas the Hitachi will not.

JB

[Leak]

Originally posted by JimmyBarnes
Found the quick fix was to remove the CD audio cable linking DVd-ROM to mainboard. Then both the squeak and pitter-patter artifacts ceased. Means I can't play audio CDs in the unit but I never do that anyway.


Glad you fixed it, but if it was the CD audio shouldn't muting the CD in on your soundcard also have fixed it?

Also, even without the audio cable you should be able to play CDs by choosing "Enable digital CD audio for this CD-ROM device" in the drive's properties dialog from the "Hardware" tab of the "Sounds and Multimedia Properties" control panel (at least that's where it is in Windows 2000) - it'll then play CD audio the same way a CD ripping application would, namely by reading the audio data off the disc and playing it as a WAV file.

np: Limp - Silent Running (Blue Skied An' Clear comp.)

[JimmyBarnes]

Originally posted by Leak
Glad you fixed it, but if it was the CD audio shouldn't muting the CD in on your soundcard also have fixed it?

Also, even without the audio cable you should be able to play CDs by choosing "Enable digital CD audio for this CD-ROM device" in the drive's properties dialog from the "Hardware" tab of the "Sounds and Multimedia Properties" control panel (at least that's where it is in Windows 2000) - it'll then play CD audio the same way a CD ripping application would, namely by reading the audio data off the disc and playing it as a WAV file.

I was unaware of either of the above. Thanks for the tips, I'll check them out.

JB

[SeeMoreDigital]

Originally posted by JimmyBarnes
...Found the quick fix was to remove the CD audio cable linking DVd-ROM to mainboard. Then both the squeak and pitter-patter artifacts ceased. Means I can't play audio CDs in the unit but I never do that anyway. Did you check that the earth connections were in the correct place?

[JimmyBarnes]

Originally posted by SeeMoreDigital
Did you check that the earth connections were in the correct place?

Which?

JB

[SeeMoreDigital]

Originally posted by JimmyBarnes
Which? Quite often the CD audio cables only have 3 pins connected instead of all 4. Usually this does not matter too much because the ground wire links to both earth pins (or is shared) but sometimes they don't meaning that you are not earthed (shielded)

I have even come across CD leads that have been incorrectly wired (ie: the earth is where the left should be) so you could check this out too!

Cheers

[JimmyBarnes]

Originally posted by SeeMoreDigital
Quite often the CD audio cables only have 3 pins connected instead of all 4. Usually this does not matter too much because the ground wire links to both earth pins (or is shared) but sometimes they don't meaning that you are not earthed (shielded)

I have even come across CD leads that have been incorrectly wired (ie: the earth is where the left should be) so you could check this out too!

Cheers

Could you describe a correctly wired cable?

I tried a number of both 3- and 4-wire cables, and reversed the
orientation at one end for good measure, but nothing stopped the artifacts apart from removing the cable entirely (tho there was a few minutes after the problem had started, when a cable was connected when the artifacts stopped.)

I found "Enable digital CD audio for this CD-ROM device" as suggestd by Leak enabled me to play audio CDs even without the usual cable
so thanks Leak. Like having one's cake and eating it too ;)

I now believe that in the several months before I got the wireless headphones, the problem was not occuring, contrary to what I first thought - DVD-ROM DMA and audio cable were in effect in this period. So most likely some fault has suddenly developed in the DVD-ROM or in the mainboard's on-board audio. Hopefully it won't get worse and the fixes in place will see me through. If not, I can disable on-board audio and add PCI audio.

JB

[SeeMoreDigital]

Originally posted by JimmyBarnes
Could you describe a correctly wired cable?

I tried a number of both 3- and 4-wire cables, and reversed the
orientation at one end for good measure, but nothing stopped the artifacts apart from removing the cable entirely (tho there was a few minutes after the problem had started, when a cable was connected when the artifacts stopped.)[QUOTE]Originally posted by [B]Yep I'll have a look for you and report back!

[QUOTE]Originally posted by JimmyBarnes
[B]I found "Enable digital CD audio for this CD-ROM device" as suggestd by Leak enabled me to play audio CDs even without the usual cable so thanks Leak. Like having one's cake and eating it too ;) This is a preferred method of connection anyway as you've got 1' and 0's being processed by your onboard audio chip rather than analogue!

Cheers