Not capturing sound?

[Suprman37]

I've been trying to capture some old VHS tapes to DVD and I'm having an issue with the sound. I was originally capturing them through QuickTV, the software that came with the capture card. I then moved on to VirtualDubMod. Whenever I try to watch the video, either through QuickTV or VDM, they play fine. However when I try to capture them, the captured files have no sound.

I've checked the capture settings in VDM and QuickTV and they both have "Capture Audio" enabled. I can't figure out what the problem is since they play through the programs normally with sound.

I'm using a...

Phillips Cap713x Video Capture
AthlonXP 2000+
Asus A7V266 (on board sound with Line In)
GeForce TI 4200
512MB Ram.

Anyone know what could be causing the problem?

[Capmaster]

Does your capture card use the PC's sound card to capture the audio? Some real early, real cheap units like the ADS USB Instant DVD used to go this route, and it's a lip-sync nightmare.

But I doubt any unit built since 2003 or so would do this. More info is needed about your capture card, since I couldn't find it on the Philips site.