There have been several previous threads on "archiving" and it's a bit surprising that no one has made reference to any of them here, although I don't recall much that would be helpful that hasn't been mentioned here, especially if your purpose is extending the life of your own personal collections for your own use.

At the risk of belaboring the obvious, it should be kept in mind that most old recordings are analog and anything you put on a computer must be digital. If one is interested in preserving exactly what is on an old analog medium that's at risk, copying (as a mirror image) to a newer analog medium using analog equipment is the only way to really save the original - as for "later conversion when better methods are available." For most people this will probably mean copying everything to tape since tape is the only recordable analog medium accessible to most. If anyone wishes to do this, an analog tape must of course be used. "Computer tapes" are for digital data, and don't do well when used for analog info.

Obviously you can't save what the record sounded like when new. You can only save what remains of it at the time of copying, and you can't make an identical copy because both playback and recording will introduce some distortion.

I must suggest for consideration that just because they're "mechanical" doesn't mean that the old records are better at retaining the original recordings than tape. I made copies to cassette tape from a number of new vinyl platters in the period from about 1980 - 1985 so that I could "archive" the originals. The originals have been carefully stored (at home), while the tapes have been hauled around and played intermittently. The tapes still sound good, while the vinyls are at best "marginably playable."

The youngsters have no way of judging it, but even the old cylinder recordings that my grandpappy had in the attic sounded better, on the hand-cranked Edison, ca. 1948, than the best "digital remasterings" of similar era stuff recently released by Smithsonian, because the mechanical records are not the same now as when they were made. When new, my impression is that many of the old recordings probably sounded nearly "as good" as many new commercial recordings from the 50s, with the exception of slightly less dynamic range and smaller useful frequency range. No existing analog recording that anyone has now can reproduce exactly what the original recording sounded like, for anything more than a few years old and certainly not for something decades old.

Once converted to digital, the copy can suffer fairly significant "degrading" and a new copy can still be made that's exactly like the first digital copy. "Fat zeroes" and "short ones" can all be placed back on the new copy at their original cleanliness, as long as the recorder can tell what's a one and what's a zero. In some cases, error correcting methods incorporated in modern recording systems can even accomodate a nominal number of "ambiguous" bits. This is an obvious advantage, for archival life, for digital data, and most people probably should archive in digital form and accept that original analog information cannot be saved indefinitely - in the original analog form.

John