12" 45 RPM records: What's the story?

Nsgarch...As the cutter cuts, it disturbs the surrounding material, like the wake of a boat traveling through water. Adjacent to the cutter is the material for 1.8 seconds earlier. I learned this so long ago that I can't give you a reference. Sorry about that.

Eldartford, if what you're saying were true, the cutter would disturb the vinyl (and VERY ACCURATELY too -- carbon-copy accurately) on both sides of the groove it's cutting. But that would only produce a post-echo (in the previous groove), because the groove in which the pre-echo is supposed to occur hasn't been CUT YET!

And if you think about it, it just can't be physically possible for a cutter to produce an accurate, duplicate, identifyable signal in an adjoining groove, across the intervening uncut vinyl.

So, I still don't buy it, but thanks for making me think about it critically; it is a bit of a brain twister;--)
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Sorry Eldartford but if we want to form a company then we should have thought of this more than ten years ago and filed a patent.

A cursory investigation indicates we might have to negotiate a patent license or find a workaround....

French Telecom Patent on Pre-Echo

Somebody already thought of it.....I knew it was too obvious!

Of course, if we just made the science up and sold a brightly colored interconnect exactly 1.8 meters long (get it - the perfect length to cancel the pre-echo); we wouldn't have to worry about a patent license...just rely on testimonials!

Did anybody find a CD with pre-echo yet?

Nsgarch, the preecho is in the other channel in the groove that has already been cut. The cutter cannot deform the vinyl in the groove yet to be cut.

What I would really like to know is how I get preecho on cds which are cut from the master tapes.