G'day Nynia,

You had better take notice of what GUEST Arkie said above!

In the late 1970s, Ampex introduced a new binder for the magnetic medium ... beautifully flexible (for new-fangled helical scan video machines) ... smooth and slippery ... hard wearing ... and it HYDROLISED in a few years! (or a few months ... or weeks ... in the tropics!). The binder was picked up and used by most major manufacturers - especially the American ones - so you have to assume that any tape from that decade is potentially hydrolised.

Even playing them once to hear what is on them CAN scrape significant portions of the binder off, to gum up your heads and to degrade the remaining signal. It is not just a matter of cleaning as Tiger suggests. Art Thieme's post covers it fairly well.

I had this as a major problem in a set of CDs I recently made from high grade Ampex Studio Mastering Tape recorded in 1984. (And I have to face it stil for a lot of archive tapes in my care. It is actually more common with top grade tape, which had embraced the new binder than with ceapies that were old (and safe) technology.

Regards,

Bob Bolton