 |
 |
I recently had to bake an old 456 reel twice to get it to play back properly. It had additional layers of confusion. It came with about 15 seconds of Dolby A tone but, after transferring it with and without, after careful listening, it turned out the Dolby was not engaged. There is a bit of overload distortion in one place. I then had to figure out if it needed an additional rebaking, Dolby recalibration, etc. It took an inordinate amount of listening time to finally decide with confidence that the distortion was in the tape and not Dolby caused and that further baking wouldn't correct it. Steve Smolian -----Original Message----- From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Jim Sam Sent: Friday, December 18, 2015 5:30 PM To: [log in to unmask] Subject: Re: [ARSCLIST] Interesting sticky-shed data point Richard, We have excellent storage conditions here and while I see SSS uniformly on back-coated polyester tapes--most tapes 3M and here >15 years--8 hours always is sufficient. Jim Sam Hoover Institution Library & Archives Stanford University On Fri, Dec 18, 2015 at 12:07 PM, Richard L. Hess <[log in to unmask]> wrote: > Tom, > > The one semi interesting data point that I have is that in 2012 when I > was at LoC, they said that they are NOT seeing the increase in baking > time requirement that many of us on this list have noticed. I > confirmed with them that the tapes they are transferring have been in > their vaults for an extended period of time. They bake 8 hours and the > tapes play fine with no residue. > > So, I take that to be at least some support for the cold, dry storage > environment that they have buried into the hillside. > > Nothing scientific, just an overall impression based on a confirmed > conversation. > > Cheers, > > Richard > > > > > On 12/18/2015 2:24 PM, Tom Fine wrote: > >> One thing I'd like to see tested is whether these dry/cold vaults >> really make any difference with sticky-shed. I know of a vault that >> has Ampex >> 406 tapes, NOS, that have been stored there since the vault was >> built, either before the tapes were purchased or soon afterwards. >> Acting on the assumption that all Ampex-branded 406 is likely >> sticky-shed, especially later-era 406 (which this is), I'd love for a >> real-deal lab to get hold of one of these tapes and test if it's gone >> sticky. If it has, I would say the cold/dry vault -- which is likely >> NOT GOOD for acetate tapes -- turns out to be no help to stave off >> sticky-shed. If the tape, or a test batch of tapes, are not sticky, >> then we have a proven data point about storage. >> >> My overall point is, I think there are still a lot of assumptions >> made about sticky-shed, which aren't proven and may not be true. The >> only thing that does seem to be true is that a sticky tape can be >> baked and it will playback in a mechanically successful manner. As >> I've said, my experience is that the audio deteriorates after a >> handful of bakes, but others disagree and I think we all admit we >> haven't done rigorous science on that. >> >> -- Tom Fine >> >> ----- Original Message ----- From: "Richard L. Hess" >> <[log in to unmask]> >> To: <[log in to unmask]> >> Sent: Friday, December 18, 2015 2:03 PM >> Subject: Re: [ARSCLIST] Interesting sticky-shed data point >> >> >> Tom, >>> >>> It is harder than you think. Work has been done and continues to be >>> done on identifying, the causation, and the remediation. >>> >>> Since we have no new tape (only NOS) to play with, controlled tests >>> are practically impossible. One paper I read on potting compound >>> hydrolysis, the experimenters made new batches of the polymer to test. >>> >>> Needless to say, that is more difficult with tape, especially when >>> we have anecdotal (at least) evidence that the process control was >>> sometimes sub-optimum. And the looooong time it has been around. >>> >>> Cheers? >>> >>> Richard >>> >>> >>> >>> On 12/18/2015 8:53 AM, Tom Fine wrote: >>> >>>> I submit, then, that we don't have a clear understanding of what >>>> causes sticky-shed. Since we know that baking makes the tapes >>>> playable, knowing the cause may not matter at this point, but it >>>> would be good to close the circle. I'm surprised the government >>>> hasn't spent more time and money on nailing this down, given how >>>> much instrumentation and audio tape is archived. It seems like one >>>> of the defense-contractor labs would have the chemistry analysis >>>> and science expertise to figure this out. It seems to have something to do with polymer science, as I understand it. >>>> But then it may not, since we see that what's essentially the same >>>> material (tapes from the same batch, assumed from the same rolled >>>> out mass of slurry) may or may not go sticky or may not go the same >>>> amount of sticky, under same storage conditions. >>>> >>>> By the way, there seems to be a similar thing with some brown-oxide >>>> acetate-backed tapes and vinegar syndrome. I told the tale of two >>>> Audiotape masters made around the same time, but likely from >>>> different batches, the A and B side masters of the MLP mono "1812 >>>> Overture." The A side tape is badly decayed from vinegar syndrome. >>>> It is actually a later-time tape than the B side master because it >>>> was mixed at the studio (music master combined with SFX master to >>>> create LP master), whereas the B side master is a first-generation >>>> recording, edited into a master. Both are Audiotape acetate-backed >>>> tapes, which have a track record of not going vinegar. So why did >>>> one go vinegar and one didn't? I think it's safe to assume they've been stored together all these years. >>>> My experience has been that Audiotape acetate-backed rarely goes >>>> vinegar, Scotch 111 variants seem to be about 50-50 and are >>>> dependent on storage conditions, Kodak is 100%, and Irish >>>> (pre-Ampex) trends more like Audiotape (unlikely to go vinegar >>>> unless stored in damp conditions). So again, why? We've talked >>>> about different impurities in the iron oxide in any given batch. >>>> Might that also relate to sticky-shed, that the impurities in the iron are the actual culprit? >>>> Both conditions seem to relate to moisture being pulled into the >>>> tape chemistry. >>>> >>>> Some food for thought, by real scientists. Too bad no one with that >>>> kind of expertise can get the time or funding to nail down the real answers. >>>> >>>> -- Tom Fine >>>> >>>> ----- Original Message ----- From: "Corey Bailey" >>>> <[log in to unmask]> >>>> To: <[log in to unmask]> >>>> Sent: Thursday, December 17, 2015 11:23 PM >>>> Subject: Re: [ARSCLIST] Interesting sticky-shed data point >>>> >>>> >>>> Back in the day, I had a few occasions where batch numbers were not >>>>> the same with bulk 1/4" (406 & 456) on hubs. Tape that was on >>>>> reels in boxes, when purchased in case lots, were consistent. >>>>> >>>>> I've also had Marie's experience with Sticky Shed where the same >>>>> tape, from the same batch (Based on the batch #'s from the tape >>>>> ends stored with the reels), stored on the same shelf, had >>>>> different levels (some with none) of SS. >>>>> >>>>> Corey >>>>> Corey Bailey Audio Engineering >>>>> www.baileyzone.net >>>>> >>>>> On 12/17/2015 7:47 PM, Marie O'Connell wrote: >>>>> >>>>>> When I was in the States I made a largish order of about 1000 >>>>>> reels of Emtec 911 open reel tapes. From memory the boxes >>>>>> contained 20 reels per box and my immediate boss liked me to >>>>>> record the batch number as part of my workflow. Not all the >>>>>> tapes in the boxes were from the same batch. >>>>>> >>>>>> We had a situation here where the Mitsui Gold CDR's, shrink >>>>>> wrapped and all, not only had pit holes in them on the gold >>>>>> layer, but when you opened the shrink-wrap and case they were >>>>>> full of dust!. We sent them back but heard that another >>>>>> institution in Asia had complained about the pit-holes and sent >>>>>> theirs back after opening them. It appears they were then >>>>>> re-shrink-wrapped and we got them! >>>>>> >>>>>> The joys of archiving! >>>>>> >>>>>> Marie >>>>>> >>>>>> On Fri, Dec 18, 2015 at 3:54 PM, Richard L. >>>>>> Hess<[log in to unmask]> >>>>>> wrote: >>>>>> >>>>>> >>>>>> Tom, what you describe is the theory. I have heard rumours that >>>>>>> was not >>>>>>> the case in Opelika. Cases were filled with reels when needed. I >>>>>>> suspect that bulk packs were perhaps a bit more likely to be all >>>>>>> the same batch. >>>>>>> >>>>>>> How wide were the jumbos in Opelika? >>>>>>> >>>>>>> Cheers, >>>>>>> >>>>>>> Richard >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 12/17/2015 9:27 PM, Tom Fine wrote: >>>>>>> >>>>>>> >>>>>>> I thought the numbers on the box and on the stickers box >>>>>>> indicated >>>>>>>> batch >>>>>>>> numbers and dates of manufacture, indicating that all pancakes >>>>>>>> in the box were from that batch and date. At least that's how I >>>>>>>> always understood 3M and Ampex boxes. >>>>>>>> >>>>>>>> -- Tom Fine >>>>>>>> >>>>>>>> ----- Original Message ----- From: "Lou >>>>>>>> Judson"<[log in to unmask]> To:<[log in to unmask]> >>>>>>>> Sent: Thursday, December 17, 2015 7:54 PM >>>>>>>> Subject: Re: [ARSCLIST] Interesting sticky-shed data point >>>>>>>> >>>>>>>> >>>>>>>> Tom, is it a documented fact that all (12) rolls (reels or >>>>>>>> pancakes) of >>>>>>>> tape in a box would be from the same manufacturing/slurry >>>>>>>> batch? I never looked, but it would not surprise me if there >>>>>>>> were different manufacturing runs on the same delivery carton… >>>>>>>> >>>>>>>> <L> >>>>>>>> Lou Judson >>>>>>>> Intuitive Audio >>>>>>>> 415-883-2689 >>>>>>>> >>>>>>>> On Dec 17, 2015, at 4:38 PM, Tom >>>>>>>> Fine<[log in to unmask]> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Hi Marie: >>>>>>>> >>>>>>>> This is very strange: >>>>>>>>> >>>>>>>>> >>>>>>>>> I have also had reels of Ampex 456 come out of the same box of >>>>>>>>>> 10 or >>>>>>>>>> 20 and >>>>>>>>>> purchased at the same time where 1/2 have SSS and the rest >>>>>>>>>> are fine! >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> I've never heard of that from anyone else. That would almost >>>>>>>>> seem to >>>>>>>>> defy all theories of what causes sticky-shed, because one >>>>>>>>> would assume by a "box" of tapes you mean a real-deal Ampex >>>>>>>>> case with a batch number on it. If that's so, it's really >>>>>>>>> freaky that some tapes in the same batch (which I think means >>>>>>>>> the same production run of the chemical slurry) would get >>>>>>>>> sticky-shed and others wouldn't. >>>>>>>>> >>>>>>>>> I'm not doubting your testimony at all, just saying that is >>>>>>>>> calls into question what is believed to be the cause of >>>>>>>>> sticky-shed, in that I can't see how the binder chemistry >>>>>>>>> could differ within a batch. >>>>>>>>> >>>>>>>>> >>>>>>>>> -- >>>>>>>> >>>>>>>> Richard L. Hess email: [log in to unmask] >>>>>>> Aurora, Ontario, Canada 647 479 2800 >>>>>>> http://www.richardhess.com/tape/contact.htm >>>>>>> Quality tape transfers -- even from hard-to-play tapes. >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>>> >>>> -- >>> Richard L. Hess email: [log in to unmask] >>> Aurora, Ontario, Canada 647 479 2800 >>> http://www.richardhess.com/tape/contact.htm >>> Quality tape transfers -- even from hard-to-play tapes. >>> >>> >>> >> -- > Richard L. Hess email: [log in to unmask] > Aurora, Ontario, Canada 647 479 2800 > http://www.richardhess.com/tape/contact.htm > Quality tape transfers -- even from hard-to-play tapes. >