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Vinyl Recording: Shifted Right Channel?

Posted: Thu Jul 24, 2008 4:51 pm
by Geiger
Last night, I recorded a vinyl album for my father (Target - Captured), for the purpose of transferring it to CD. The recording sounds fine played back, and I know the sort of stuff I'll need to do to get it ready for burning (I've done this twice before), but I noticed something odd with the waveform.

For lack of proper terminology, the right channel appears to be shifted such that the top of the waveform is flat and with the peak height difference from the left channel being added to the bottom (flat on top, extra spiky on bottom). Like someone pushed on the top of the waveform until it was flat.

I'm probably not going to do anything to it, since it sounds just like the album, but I'm curious as to what causes this effect and how it could be affecting the audio.

Re: Vinyl Recording: Shifted Right Channel?

Posted: Thu Jul 24, 2008 5:03 pm
by kozikowski
If the middle of the blue waveform isn't in the middle of the timeline (too high or too low), then you most likely have battery voltage or DC mixed in with the sound. You can get rid of it with the Normalize tool, but you can't ever get rid of the distortion that way. Once you capture sound with top or bottom squished, you have permanent distortion in the show.

Something in the capture process, which is supposed to separate battery and operating voltages from the sound, is failing.

Is this a USB turntable by any chance? They're notorious for causing instability and damage.

The blue waveforms are carried by separate processes than the actual sound. So tits possible to get them out of step. If you export a small section of the performance with damage to a WAV file and then open up that WAV file, is it still damaged?

Koz