[GRC]

Originally Posted by Tubular

btw, I'm definitely not an analog tape expert. What is 'tape baking'?

Darn, your avatar was so convincing. Analog tape has two layers, sometimes three - a plastic strip, a coating of magnetic material, and sometimes a matt back-coating to encourage neater winding; you need some 'glue' or binder to hold them together. In the 1970s, the formulation that Ampex used was changed, for some reason, and the new formulation was faulty, in that it reverted to a sticky, goo-ey state, rather than staying dry. The end result being that when you play some Ampex tapes from this era, they play for 5 minutes before clogging up the tape heads, guides, etc, and sometimes bringing the tape recorder to an embarassing halt. Quite a conundrum; Ampex tapes from the 1950s are better preserved and more usable than those from the 1970s......

The remedy is to slow bake the tape in a finely-controlled oven to dry it out. Once the binder has dried, the user is encouraged to play back once, twice, or an absolute minimum number of times, and make darn sure of getting a usable copy made, onto digital media or otherwise, before the binder loses its cohesion again.

That's the short version - google 'Ampex baking' or 'Ampex shedding' to get a good picture of the hoops that those in the recording industry are having to go through to salvage what is fairly recent material.

Pictures here

Regards, Graham