reel-to-reel rewind sticky shed syndrome tape

Archived from groups: rec.audio.pro (More info?)

Lew <lwsrndn@hotmail.com> wrote:
>I have some old 1/4" audio tapes that were masters of some studio work
>recorded in the sixties and seventies. There are a few of the older
>tapes that are acetate. The rest are mylar, most of which are
>pre-1975. I want to transfer all of these to CD.

Acetate tapes do not have stickey shed problems. They have very different
problems, mostly due to the way they expand and contract with humidity
changes. Baking acetate tapes will destroy them.

SOME mylar tapes from the end of that era may have sticky shed, but only
backcoated types. If you are hearing squealies with non-backcoated tapes
you have a different problem and not one that baking will help.

>For the tapes that have already shown some sticky shed syndrome, what
>is the best way to take an old tape, run it from one reel to another
>and then rewind it before baking it? If I do that on my Teac 3440, the
>tapes with sticky shed syndrome really gunk up the machine in short
>order, because there are a few non-rotating contact points on the tape
>as it moves through the deck. I know I will have to bake these tapes
>to make them playable. Before I bake them though, I want to run them
>gently from the reel they have been on for years to a blank reel and
>then back again, so they will have less stress and be loaded on the
>reel uniformly (no exposed edges).

You don't need to do this. However, if you have regular shedding issues
this can be a good thing. But if you really do have sticky shed, bake
the tape. When it bakes, it will become thinner and you can then rewind
it and get a better pack.

>It would seem to me that a slow-speed rewinder would be just the
>ticket, but I have never seen anything like that. How do the pros do
>this? How do they prepare a mylar tape for baking that has been
>sitting on a reel for twenty years?

The 3440 is not exactly a precision machine and it's not really known for
good tape pack. But on a professional machine you should be able to fast
forward and get good packing without any problem. The 3440 also has a lot
of guides that contact the tape, which makes it probably a bad choice for
archive material that is shedding.

>Also, what is the best way to transfer an old acetate tape to CD?

Put it on the machine, align to tones, roll tape. Plug the output of
the recorder into the converters which go into the CD recorder. Watch
it. If it's buckling a lot, it may need to be humidity-stabilized or
it may be stretched. If the tape is cupped (and that was a sad fact of
life with acetate stuff), babying the tape tension controls may help get
good contact.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Archived from groups: rec.audio.pro (More info?)

"Lew" <lwsrndn@hotmail.com> wrote in message
news:1109720341.945527.197230@f14g2000cwb.googlegroups.com...
>I have some old 1/4" audio tapes that were masters of some studio work
> recorded in the sixties and seventies. There are a few of the older
> tapes that are acetate. The rest are mylar, most of which are
> pre-1975. I want to transfer all of these to CD.
>
> For the tapes that have already shown some sticky shed syndrome, what
> is the best way to take an old tape, run it from one reel to another
> and then rewind it before baking it? If I do that on my Teac 3440, the
> tapes with sticky shed syndrome really gunk up the machine in short
> order, because there are a few non-rotating contact points on the tape
> as it moves through the deck. I know I will have to bake these tapes
> to make them playable. Before I bake them though, I want to run them
> gently from the reel they have been on for years to a blank reel and
> then back again, so they will have less stress and be loaded on the
> reel uniformly (no exposed edges).

You need to make sure what sort of tape you have before you go baking. You
also need a precision oven. I have found that the thermostats in domestic
ovens are not precise, even slightly. This may have changed with newer
ovens. And the thermal inertia of the elements makes it trick to keep a
consiistant temperature without overshooting.

> It would seem to me that a slow-speed rewinder would be just the
> ticket, but I have never seen anything like that. How do the pros do
> this? How do they prepare a mylar tape for baking that has been
> sitting on a reel for twenty years?

For re/winding try running the tape straght from reel to reel, avoiding the
tape path through the block (you'll need to trick the tape sensor arm or
lamp). You will need to apply judicious hand-pressure to keep things under
control though.

> Also, what is the best way to transfer an old acetate tape to CD?

Basic: play tape into CD-Recorder

More sophisticated: play tape into computer, clean up, edit, whatever, and
write to CD.

geoff