This site describes a method of extracting audio off scanned images of vinyl records. While this method creates exceptionally noisy samples, you can definitely hear the underlying music. Unbelievable. http://www.cs.huji.ac.il/~springer/
Graham, unbelievable is how you found this page !
This brings to memory 15 or so years ago promise of a laser based LP turntable that would without contact extract info from the grooves with better than phono cart rersponse.
I don't think that the project came to fruition, but maybe modern cheap digital electronics might make it viable.
I read a report from a comersial show in a swedish/danish HIFI Magazine HIGH FIDELITY about a company that had been working with a laser based turn table. They had had been working with it since the late eighties and finaly this year they had a working prototype now. this was only two months ago.
The US National Library of Congress for their sound archives use a stylus that is smaller than normal so that it reaches lower in the groove, hopefully to an area that has not been touched by a normal "plough", er, stylus.
Referring to the small stylus, to track a record groove, in the early 1970s, I owned a phono cartridge made by a company called "Empire". It had THREE stylii that could be interchanged easily:
- A narrow elliptical stylus for tracking lower than is usual in the groove.
- A wider stylus for tracking higher than is usual in the groove.
- A normal sized spherical stylus.
The idea behind the wider and narrower stylii was that you could track lower or higher than the usual stylus, thus avoiding presumed groove wear or damage.
The spherical stylus was used for playing a limited number of record brands which were "predistorted" for spherical stylii. Back before the advent of elliptical stylii, there was a problem with distortion that increased towards the extreme center of the records due to a "pinch" effect...the shorter wavelengths towards the center of the records were harder to track with spherical stylii. Several companies, (I think London and Decca were two of them) added an inverse distortion to compensate for this.
When the elliptical stylus was introduced, it could trace the shorter wavelengths more accurately. BUT, London and Decca records had higher distortion, because they were optimized (pre-distorted) for spherical stylii.
For that reason, the top of the line of the Empire cartridges had all three stylii as mentioned above.
I was using it with an AR-XA turntable, tracking at about 1/2 a gram. It was GREAT!
I like to record my lp's to my mini disk recorder so that I can erase any track that skips or needs cleaning, then I will use the digital output on the minidisk player to record it to cd on my pioneer burner or onto the computer. All that vinyl gets real heavy to haul arouund