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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 naughty tapes! Cheers Marie 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. > > > http://www.ataestuder.com/technical/acoustic-scrape-flutter-detection-system/ > > 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! > > http://www.ataestuder.com/technical/shro-explained/ > > 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 >