Random track drift

Cubase
1

This is new to me - I imported an LP straight from the disk. Turntable to stereo amp for RIAA compensation, Line out to Focusrite USB interface. 44.7 /16.

Out of 9 tracks transferred, only one has this issue: The first half of the track is fine but the second half show random drifting in the right channel - a few microseconds both ways, but enough to cause phasing with the other channel… sometimes behind, sometimes ahead, as compared to the other (Left) channel. Drift is a few seconds long, and random. It sort of looks like time stretching and compressing…

Is there a way to align the portions of the drifting channel to the other channel?

Thanks in advance..

2

You refer to both “microseconds” & “a few seconds” - can you clarify what you mean.

Is there any audio processing happening? Are you sure the source material doesn’t have the same issue?

3

I meant total number of audio seconds that drifts back and forth. Actually more like 2 minutes. The amount of drift is a few micros, maybe tenths, off. Since the original recording is analog, I doubt the issue is in the LP itself.. Like, a section drift ahead, then slide back into alignment, the drop behind, and there’s no pattern to it.. The solution would be to drop markers in the "reference track, and line them up with the drifting track, and align them. I can’t cut the track into sections / adjust length / re insert because the drift is gradual… I’ve never seen this before. I’m going to do another transfer and see if I get the same issue..

4

Is there any chance that a “phase alignment” plugin could help?

5

Just to put it into perspective: with a sample rate of 48 kHz the duration from one sample to another is 20.8 microseconds.

Making another recording seems like a good idea.
Have you closely listened to the original and the recording? The phase issues are positively not present in the original?

6

Yes. You might also try swapping the cables left & right and see if the problem follows along. Also you could try record using a different program than Cubase.

Having the problem change over time suggests to me it is occurring in the analog domain where everything can influence everything else. For example purposes only, a space heater turning on could warm one cable a bit more than the other, which causes its resistance to slightly change which then shifts the phase a bit.

7

True - I could fiddle with trying to fix the existing recording, or re- record it, and hope the problem is in the A/D process.. Fingers crossed..