No audio only when S-video is plugged in with the RCA jacks

M

madbot

New Member
Hi there,

I've been wanting to convert old family tapes on 8mm cassettes. I bought myself 1) a RCA/AV to USB adapter, 2) a 3.5mm to RCA cable, and 3) an S-video cable. Initially, with just the first two items, I could get audio, but no video. After having bought the S-video cable, whenever it's plugged in I get no audio input. I have tried the solutions below but to no avail.

Solutions attempted:
  • Separate the audio and video source
  • Remove the video and audio capture device then re-added them
  • Disabled all other audio inputs into OBS save for "USB Digital Audio"
  • S-Video cable + yellow jack
  • S-Video cable + yellow jack + red jack
  • S-video cable + yellow jack + red jack + white jack
    • With the white jack plugged in, regardless of the presence of the S-video cable, there's some loud 'static' sound

Where I bought each device:
 
A

AaronD

Active Member
To my knowledge, there's no actual standard for analog A/V on 3.5mm TRRS. So the RCA color-code could be wrong, and even the common ground could be wrong. Yay... :-/

The "loud static sound" could be the video signal being interpreted as audio. Again, don't trust the wire colors, or anything else when using 3.5mm TRRS for analog A/V. Read the camera's documentation, and/or use an adapter that is made specifically for that camera. If neither of those is an option, you might end up making your own adapter by tedious trial-and-error...or using a different camera.

Also, S-video does not carry audio. Its additional wires/pins are to separate the color and brightness information, compared to Composite (RCA yellow). So you still need the separate audio connections (RCA white and red) when using S-video. It's slightly better quality, so do use it if you can...*plus* audio because it doesn't include it itself.
 
M

madbot

New Member
Thanks! I got it to work now! Given that info about the colour-codes, I decided to plug in both the white and yellow, but switch it around i.e. yellow to white and white to yellow. Now I'm having both audio and video
 
koala

koala

Active Member
According to your capture adapter description, the yellow cable is cvbs (video signal), white is left audio, red is right audio. Old analog devices either output both audio and video with cvbs through 3.5mm jack (connect all 3 rca cables). In this case, the 3.5mm plug has 4 tiny sections as for your RCA cable. Or they output audio and video separately, video with S-Video and audio with stereo cable through 3.5mm jack. In this case, the 3.5mm jack only has 3 tiny sections and it is an ordinary stereo jack. If your device outputs via s-video, try an ordinary 3.5mm-to-stereo converter instead of the video rca cable. Check with the documentation of your vhs device which variant of the 3.5mm jack it has.

One thing is certain: if video is working with the s-video cable only, you should not connect the yellow plug, since it also expects video, which is apparently not provided by your vhs device's 3.5mm jack. Connecting just the red and white plugs for audio might work, depending on where the inside the jack the plug is tapped, but if it is a stereo plug, it's probably not really compatible with a 4 section plug.
 
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