I have 2 x Studer B67 machines that we modified in about 1996-7 and removed
the erase and record heads for low friction. They work great and I have
found the need for isopropyl lessened. I only use that technique with very
On Thu, Aug 22, 2013 at 2:48 AM, Fred Thal <[log in to unmask]> wrote:
> Agreed that behavior in gravity un-spooling is telling. Yet I know of
> at least one case where layer-to-layer adhesion was not a binder
> chemical degradation issue, but a mechanical one. The tape was out of
> tolerance for width (slit too wide), had edge fraying resulting from
> playback on the wrong equipment, and when wound and stored under
> tension, the frayed edges stuck together, slightly.
> Squealing can also stem from both chemical and mechanical causes.
> Many, many tapes in fact squeal, it's just a matter as to what degree.
> You can even make good tapes squeal audibly. Looking into this
> phenomenon with acoustic detection is useful and educational. For me,
> it's been fascinating.
> You certainly do not need to order the ASFDS option mounted into one
> of our expensive SHRO headblocks to start listening to tape mechanical
> motion sounds. Remarkably inexpensive miniature microphone capsules
> and audio op-amps are available. Just chose a pair of headphones and
> make your own hand-held electronic acoustical stethoscope. Then you'll
> have a tool that ought to be in the possession of anyone working on
> professional tape machines.
> ATL doesn't use tape lubricants. Perhaps because we don't have to.
> When a tape's lowered glass transition temperature is causing
> problems, why would you needlessly heat up the tape with unnecessary
> friction in playback? As someone in this thread hinted at, low
> friction is the goal. So get rid of the erase and record heads!
> And stop believing the nonsense promulgated by old-school recording
> industry people. You do not need to keep a tape machine record-capable
> in order to be able to align and test it.
> Instead, chose a reproducer tape transport that is servo constant
> tension, has all-rolling straight-line bypass of the headblock in wind
> modes and that allows easy, independent tension adjustments to be made
> by the machine operator. And properly train your operators.
> For those who are stuck using tape transports with fixed pin lifters,
> try to always thread bypassing the headblock and lifters when
> re-winding, if it is possible to do so safely. Viewing tapes suffering
> from a softening of their binder chemistry, under stereo microscopy,
> quickly convinces one that fixed pin lifters are to be avoided.
> Fred Thal