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In Reply to: Re: It's in the grooves posted by Christine Tham on January 2, 2007 at 22:18:21:
Mastering lathe cutting pitch does NOT effect the level of the recorded signal. It's the other way around. The level of the recorded signal controls the cutting pitch. The cutting system pre-delay simply tells the lathe what pitch must be set one revolution ahead for the upcoming signal. That's how more than 15 minutes of playing time can be achieved on a 12" LP. Prior to Vari-Pitch, all cutting was done at a constant pitch setting with no accomodation for levels.I hate to burst a bubble here, but the vast majority of modern (mid-80s to present) disk cutting systems use a pcm digital delay to feed the cutter head, regardless of the recording source. In the case of analog tape, the direct tape machine output feeds the pre-delay control signal to control the cutting pitch. A pcm digital delay of the same signal feeds the cutter head. Exceptions would be where the system is set up with an analog pre-delay tape head prior to the main tape machine PB head. That's the way it was done prior to the advent of high-quality pcm digital delays. I'd like to think that ace mastering engineers such as Steve Hoffman would be using the all-analog method rather than a pcm delay in the chain. I've been out of the loop in LP mastering awhile so I don't really know.
Best Regards,
Follow Ups:
HowdyAt MikeL's house on his Rockport Sirius III with single sided half speed mastered 45... discs I thought (just a few times) I could hear a pre-echo, telegraphing or a shadow of what was coming a revolution later, since I don't believe it was a failing of the TT or the disc, I wounder if it was a change in the recording pitch when a change in dynamics was approaching. Does this sound possible or is it something more mundane?
What you're hearing is likely "pre-echo." That can occur as a mastering defect if the cutting pitch wasn't expanded enough. Normally, at the beginning of each track the pitch is supposed to be overly coarse (lots of land between the grooves) to minimize pre-echo. Pre-echo can also occur as a pressing defect, particularily if the vinyl press is set up with too much pressing pressure on the "biscuit" of vinyl.You could also be experiencing "print-through" from the original analog tape if that was the source for the recording in question. You'll hear print-through a lot on older analog tapes with no noise reduction or that were recorded too "hot" to tape. Frequently, just being stored for a long time - and perhaps with too tight of a tape wind - the print-through occurs.
Best Regards,
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