Pcm Crackle, No Pop Or Snap, Audio distortion in PCM format

[Kneller]

When capturing Audio at PCM standard the audio recorded, not previewed, had allot of distortion. By this I mean crackle which is as if the record volume is set too high. (Similar to when you set the record volume too high on a and old cassette deck). I have changed the volume slider in Windows and on the volume meter in Virtualdub. Nothing seems to make a difference. The only thing that removes the crackle is recording in MP3 format.

[Dragonsf]

Is this distortion sort of "overdrive", i.e limited by the 16 Bit barrier, or additional impulses, induced by frame-errors?

[Kneller]

No the problem isn't limited to 16 bit audio. I also happens on 8 bit on 44 and 22 and 11 KHZ. It seems all PCM formats. I have looked on Lukes guide and tried it not looping through the video card (ATI AIW 8500DV), no difference.

Really appreciate you time. Any other direction I may have overlooked?

[Kneller]

Sorry forgot to mention that there are no dropped frames, (I presume this is what you mean by fram errors?)

[Dragonsf]

Do you only get this effect, when capturing video or everytime?
What about your HDD?How fast is it, what type of DMA?

[Kneller]

I only get this crackle when capturing via VirtualDub. Using the ATI video recorder this problem doesn't occur.

This kinda makes me think its VirtualDub. Which I have removed, including reg entries and added again and the problem still happens.

HDD is 80GB 7200rpm Western Digital, (It hasn't got the 8mb buffer, too pricy!). Its ATA is 100. Limits of the motherboard.

So why would capture using MP3 not suffer from the same distortion
Maybe this is where I should be concentrating to fix this.

(Actualy is it always better to capture in PCM? Is there a losless codec for audio? Why capture audio in PCM?)

More Q's and no A's. Well get there!

[Kneller]

If I chose Sony Hi 8 from the drop D List all works well. (This is OK as the source is mono). So I am going to try different presets and change the format and rates from their drop D Lists.

I have the sound going directly from the VCR to Sound card. So as a newbie I geuss I'm using the Card not AC97, which I think is on the video card right?

BTW, any idea why I have to keep going into ULEAD to change the format of the signal from NTSC to PAL. Why would it keep defaulting to NTSC? How can I change from VirtualDub. (I want to keep away from ULEAD, it has wasted so much of my time)

Ta for your help.