I recently unearthed 26 brand new 10 1/2-inch reels of 456 from 8 different batches. I checked one reel from each batch by playing them back and forth at 15ips (I only played the bad reels in one direction – that was enough!). The following batches were bad:

90297, 91049, 91055, 91079 and 91149

The following were fine:

94132, 94133, 94298 and 96190

The reels that were bad did not squeal during playback, but left debris on the heads and guides that was just barely sticky, so these are obviously in the beginning stages of deterioration.

All of these were Ampex (pre-Quantegy) tapes purchased in the early 1990s. Batch 96190 have lighter grey boxes as opposed to the textured, darker grey background found on the earlier batches, and the reel labels appear to be silk screened, rather than having sticker labels. None of these reels have the old rainbow-style logo.

I would guess that the good batches will probably remain OK – they’ve had a good 17 years to go bad and would probably have done so by now if there was a problem.

For whatever it’s worth…

Gary Galo
Audio Engineer
SUNY Potsdam
…speaking for himself

These tapes were badly warped due, most likely, to the vinegar-syndrome induced differential shrinkage. Other factors may have been poor winding during long-term storage (I had received them after several attempts to play them on another machine).

Not only was the tape cupping about its centre axis (with the basefilm shrinking so the edges were pulling back from the tape plane (away from the heads), it also had extremely wavy edges. In addition, the tapes would not lie flat on the reel due to the dimensional changes that were strongly embedded in the tapes.
We were able to play this tape on our stereo (NAB) A80, but discovered it was a 1/4 track tape (the original source had said it was half-track mono). We elected to stay with the A80 because:

• The A80 has the stabilizer roller which tends to “break the back” of cupping
• We had already adjusted the machine to have substantially higher tension to help flatten the tape–this was clearly a case of wanting the knobs to go to 11 or 12, but we had to settle for 10 on the play tensions.
• We do not have a four-track head for this machine AND the machines for which we have compatible heads do not have as easily adjustable tensions or the ability to safely set the tensions as high as we did on the A80
• The original recording was off-air AM radio after a trip of 1,000 miles through landline telco audio networks from 1964

So while the reproduction was only fair, we maintained good tape-to-head contact despite the inability to play this tape on other machines. If the content had been better fidelity and the client had been willing to pay for mounting a four-track head on the A80, we might have achieved some improved noise performance, but the original recording was quite low level (even correcting for the 1/4 track mismatch). Depending on segment, VU meter zero for the quarter track recording was somewhere around 15 nWb/m! We could hear recorded hiss,  however, over the tape noise even in this configuration!

We were able to improve listenability by using a filter that matched the playback bandwidth to the recorded bandwidth (it appeared to be about 200-3500 Hz, we filtered for 200-4000 Hz) and it sounded about as good as we would have expected hearing over a transistor radio in 1964. Further processing with Algorithmix Noise Free Pro reduced background noise (including random crowd noise, but not loud cheers–it was a football game) and made the announcers pop out more, so if someone is intent on listening to the details of what the announcers said, this would be easier to listen to, but less authentic to the sound of the original broadcast.

These tapes were transferred somewhere near their effective end-of-life. It would have been better if these tapes had been transferred 10-20 years ago. Based on other experience with Kodak tapes, I am not surprised with this. Interestingly, the Durol basefilm in its present state of decay was not translucent as most magnetic tapes are, so translucency of basefilm is not a 100% accurate test for acetate basefilm.

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Here are the ones with the picture of the chamber orchestra
http://www.richardhess.net/restoration_notes/111.jpg (red 7″)
http://www.richardhess.net/restoration_notes/120.jpg (orangy-brown 7″)
http://www.richardhess.net/restoration_notes/200.jpg (blue 7″)
http://www.richardhess.net/restoration_notes/311.jpg (grey-green 5″)

The moiré pattern you may see is the screening of the printing beating with your monitor.

These are earlier boxes for two if the above
http://www.richardhess.net/restoration_notes/111(A)_early.jpg
http://www.richardhess.net/restoration_notes/120(A)_early.jpg

And then it all became standardized in the 1970-era box
http://www.richardhess.net/restoration_notes/200_1970.jpg

When I get a chance, I’ll scan the box between the musicians one and the 1970s one.

We hope to update this as we come across more types. January 2009 was, sadly, fruitful in finding at least some batch(es) of two tapes from 1990 (Agfa PEM 526) and 2003 (Emtec SM911) are degrading. The Emtec SM911 was thought to be more-or-less immune from this disease. As of this writing, it has been confirmed that batch number B0134007 was involved.

Agfa PEM-526 exhibited this odd behaviour. The tape was recorded in 1990.

There is also a discussion about PEM-469 showing similar behaviour here.

For a current list of degrading analog tapes, click here.

Teaching people how to identify tapes that are suffering from sticky shed syndrome is often difficult.

I would like to propose that a careful inspection of how the tape comes off the pack may be a good way. Please provide comments as to how it’s working for you.

The tape should come off the tape pack at a precise tangent to the tape. If the tape starts to adhere and not pull off straight, that is a sure sign that the tape needs baking.

Of course, don’t bake acetate tapes even if they show this indicator, but on the last batch of questionable SSS tapes, I’ve been looking at this and it’s a fair indicator, and it seems to show at the outer edge of the pack.

More than one “test” or “factor” is needed to be sure, but this one is looking good.

Another almost sure sign of SSS is brown oxide and black back-coat.

I have just completed about 25 seven-inch reels of circa 1960-1965 acetate tapes (Scotch 111A, Audiotape, Soundcraft, Ampex 511, etc.) and about 20% of the tapes showed evidence of spoking after being played on the A80. These were rewound (approx 120 in/s under capstan control) on the Racal Store 4DS and then played at 15 in/s back onto their original spool.

With the heads removed, there are no fixed guides that contact the tape, just the two rolling tension guides and the capstan.

For photos of the Racal Store 4DS, please look here where I discuss its use (with head/guide assembly) for playing squealing tapes.

Please also read this post for a “do not try this at home” note.

I was getting rather frustrated and since it was a four-track tape and one of the techniques that is supposed to reduce squeal is to play the tape faster, I dragged out my Racal Store 4DS instrumentation recorder which has a 75,000 Hz bandwidth at 15 in/s and played it at 15 in/s and digitized it at 88,200 samples per second. After slowing it down 4x and ending up with a 10 kHz bandwidth (which I subsequently truncated to 5 kHz since there was no useful information above that, but lots of noise–same as the non-squealing portion of the real-time transfers on a Studer A810).

 

Why did it work? — That is the big question. I suspect lower tape tensions than even the reduced-tension settings on the A810 and different head geometry were major factors, plus overall shorter unsupported tape spans, and few stationary objects contacting the heads, but there was still an erase and record head which had been removed from the A810. I think that the 4x speedup helped greatly. I also turned up the outside air (how I cool the studio in the winter–I like my fresh air this way–in the summer, of course, it’s connected to the central air conditioner) which kept the tape and recorder cool. I also think that the Racal Store 4DS doesn’t heat the tape and head assembly as much as most pro audio recorders do.

I received great support and wonderful ideas on both the Ampex and Studer mailing lists. Special thanks are due Jay McKnight who has been a supporter of speeding up the tape to eliminate squeal (which is really stick-slip and causes frequency modulation of the audio). I had avoided the 4x speedup on the A810 because of the signal electronics bandwidth limitations. While in this case, 20 kHz would work fine, I wanted to digitize with 40 kHz bandwidth to make sure I wasn’t losing any highs.

There may be room for misunderstanding as to the precise topology of the Racal Store 4DS tape path. Here is a brief explanation. The tape comes off the top of the supply reel and around the top-mounted tension sensor which is a roller. The tape then is unsupported from that roller until it enters the head area. The large diameter device at the top of the head area is merely a tape guide. It is both a “face” and “edge” guide both in and out and does not rotate. Next the tape passes the erase and record heads on the left side. The heads are on the outside facing the centre. Then the tape turns 180 degrees around the capstan motor’s soft capstan. The capstan also drives the mechanical footage counter. As the tape heads up, it passes the reproduce head and then encounters the tape guide on the other side. It then goes over the tension roller at the top and onto the takeup reel. The reel servos are interesting as they are fast and can drive the tape in either direction. This is useful since there is no pinch roller. The photo below shows a closeup of the head area.

 

As an aside: you can infer from the above picture that the complement of tape machines in my studio changes. The Studer A810s in the background are being set up to record full-track mono archival reels of some cassettes.

Before running out and purchasing one of these machines, please read this post:
http://richardhess.com/notes/2008/01/09/using-the-proper-toolsand-dont-try-this-at-home/

For several years, we have been discussing the differences between Sticky Shed Syndrome (SSS) and Loss of Lubricant (LoL). It appears from my latest research (presented at the 2006 Audio Engineering Society’s 121st Convention in San Francisco in October) that LoL does not really factor into the equation for most tapes and that an overarching failure mode is Soft Binder Syndrome, or SBS. Sticky Shed Syndrome appears to be a subset of SBS.

The classic recommendation for tapes suffering from SSS is to bake them and, for now, the continued recommendation is to bake tapes for which baking works. These include:
Agfa (pre-1990): PEM 468, PEM 469
Ampex/Quantegy (1970s-1980s): 406, 407, 456, 457
Note: Recent reports indicate that these problems may exist in tapes made in the 1990s
and later, even under the Quantegy name.
Audiotape/Capitol (early 1980s): Q15
Note: This tape may or may not respond to baking. Some tests will be conducted soon.
Scotch/3M: 226, 227, 806, 807, 808, 809
Scotch 250 has also exhibited some tendency towards SSS

For a current list of degrading analog tapes, click here.

Baking (or incubation) times are getting longer, and 12 hours is not uncommon for 1/4-inch wide tapes. Some tapes need to be re-baked after partial unwinding due to centre-of-reel increased inter-layer pressures. There is some discussion of pressures and tensions here.
If these are squealing and leaving significant deposits, they should be baked (at your own risk). The now-expired Ampex patent for baking tapes can be found here. Almost all SSS tapes are back-coated tapes and the interaction between the magnetic coating and the back coating may be part of the problem.

Tapes which squeal (and generally leave less of a deposit and are generally not back coated) appear to be suffering from SBS. SBS appears to be a change in the glass transition temperature of the magnetic coating. The glass transition temperature (Tg) is the point where the plastic turns from smooth to rubbery. If the Tg falls below the temperature of the head (slightly above room temperature due to friction and player heat dissipation) then the tape is likely to squeal. Small deposits of magnetic coating on the head or other fixed surfaces will exacerbate the squealing. Of course, the drop in Tg is not an isolated phenomenon, but rather a symptom of serious binder degradation.
Lowering the temperature of the playback environment will permit successful playback of some tapes suffering from SBS. We currently have a dedicated refrigerator with both a reel and cassette machine inside. Others have reported success in using an outside balcony during cool/dry weather.

Baking a tape that generally exhibits SBS (and not SSS) may exacerbate the condition and it is not recommended to bake suspected SBS tapes.

Tapes which appear to be suffering from SBS include:
Scotch/3M: 175 and Melody 169 (a seconds brand of Scotch)
Sony: PR-150
Pyral: (type numbers unknown for this French tape)

For a current list of degrading analog tapes, click here.

We have seen cassette tapes also suffering from SBS. These were generally made from pancakes and the tape type is unknown.
As an alternate, you might try Marie O’Connell’s tried and true method shown here. In this case, it appears that the isopropyl alcohol is acting both as a lubricant and as a coolant, and may be also acting as a solvent to remove or inhibit deposits from the tape onto the fixed surfaces.

We know that the sealed can will accelerate the vinegar syndrome degradation. The big question is are these tapes an anomaly or the mine canary for some (or all) acetate tapes?

The composite photo below shows some of the conditions that we found. Note especially the rolled outer strands showing extreme shrinkage from vinegar syndrome.

Click for a larger image.

We were able to transfer these tapes,  but the sound quality suffered due to the unsteadiness of the tape transport. The quality of the sound was due mostly to the fact that this was recorded at 30 in/s (probably 77 cm/s) with a full-track head. Nothing beats areal density for robustness.

I recently came across a 3-inch reel of acetate tape, not in its original box, that showed the following pattern in the box. This tape was recorded in Fall of 1964 and the photo was taken on October 2006, 42 years later. The tape played well, considering it was originally recorded at 1.88 (1-7/8) in/s.

All of the outgassed material that was absorbed by the cardboard was no longer free to degrade the tape.

For a current list of degrading analog tapes, click here.

Fellow restorer Doug Pomeroy sent me a photocopy of Herman Burstein’s “Tape Guide” article from the May 1977 issue of “Audio” magazine. Robert Coe of Manchester, CT, wrote in saying “…some of these [Scotch 175] tapes have developed a high frequency chatter or squeal which is mechanical and can be stopped by rubbing the tape with a light coating of talcum powder. The squeal only occurs on the Scotch 175 tape even when used with several different brands of tape machine.” Burstein replied, “Yes, I’ve heard other complaints about squeal, sometimes involving Scotch tape which is not surprising in view of 3M’s large share of the market, but yours is the first complaint about 175 tape.” He went on to say that another 3M tape exhibited this but it was limited to the batch and 3M replaced it.

We do not recommend the talcum powder approach as it overall has proven to be a bad idea since it gums up the machines and increases spacing loss more than other solutions.

Doug is currently having a joyous bout with 175 but Art Shifrin apparently has a proprietary mechanical fix to the tape deck that allows playing 3M 175.

We are researching more about 175 and hope to have updates. The use of decamethylcyclopentasiloxane (D5 or cyclomethicone) has had mixed results with 175 and Sony PR-150, another known squealer.

There are many possible causes for this adhesion (or pinning, as it is sometimes called). For this tape, we believe moisture intrusion and poor storage conditions contributed to the problem. It is often a problem with plastic leader tape.

Slow unwinding has reportedly helped, as has cold, dry storage for an extended period.

This tape  (Melody 169) also squealed, but we finally got an acceptable transfer. Fortunately, this was recorded on only one track, and it wasn’t the one with all the holes in this picture.

For a current list of degrading analog tapes, click here.

For several years, we have been discussing the differences between Sticky Shed Syndrome (SSS) and Loss of Lubricant (LoL).

Recent work in which I’m participating seems to indicate that what we thought was happening in both instances may not be really what is happening.

For now, the continued recommendation is to bake tapes for which baking works. These include:
Agfa (pre-1990): PEM 468, PEM 469
Ampex/Quantegy (1970s-1980s): 406, 407, 456, 457
Note: Recent reports indicate that these problems may exist in tapes made in the 1990s
and later, even under the Quantegy name.
Audiotape/Capitol (early 1980s): Q15
Note: This tape may or may not respond to baking. Some tests will be conducted soon.
Scotch/3M: 226, 227, 806, 807, 808, 809

If these are squealing and leaving deposits, they should be baked (at your own risk). The Ampex patent for baking tapes can be found here.

The classic test for determining if a tape is suffering from LoL has been to bake it and see that baking fails. The assumption has then been that it is loss of lubricant. This test, however, may exacerbate the condition and it is not recommended to bake suspected LoL tapes.

Tapes which appear to be suffering from LoL include:
Scotch/3M: 175 and Melody 169 (a seconds brand of Scotch)
Sony: PR-150
Pyral: (type numbers unknown for this French tape)

We have seen cassette tapes also suffering from LoL.

There are several ways to address playing LoL tapes, but, for the moment, we are not prepared to publish anything definitive beyond Marie O’Connell’s tried and true method shown here.

One of the interesting things about this particular tape was it had been recently wound on a constant-tension professional machine prior to shipping to me.

We think that the entire tape had not been re-wound, allowing the higher tension wind to compress the inner core slightly, causing this cinching. After transferring the tape (which didn’t show much ill effect for its cinching), we still found it difficult to get the tape to wind smoothly on the reel.

Therefore, our current suggestion is if you find a tape like this, do not rewind it and attempt to clear up the cinching unless you are also ready to transfer the tape, as there are no guarantees that it can be wound better after unwinding.

Please see this post for an update (2008-02-15).

Notice how the complete strips of oxide exist on their own, independent of the clear “leader” to which they previously were attached.

I immediately called the client and informed him that this portion of the tape would not be salvageable. He requested I attempt to salvage as much as possible as it contained many family voices from Europe.

I opened the cassette and it looked intact, except the tape was flaking. The flaking had only just started as he was playing, so we went and pulled off the smaller takeup hub (at the bottom in this picture) and found solid tape.

We know nothing of the storage history of this tape, other than it was sent from Europe about 2004-2005 (this is written in March 2006). The dark spot on the side 2 label has me wondering what befell this tape. Nothing looked overheated or charred inside. The specks on the paper and on the window of the side 2 shell half are pieces of flaking oxide.

We proceeded to unspool the supply side, in some instances, the backing and oxide would come off as two interleaved strands, totally unattached to each other. Of course there is no practical way to re-adhear the oxide to the backing. We kept pulling and pulling and finally found solid oxide. We spliced the two halves together.

Note the pile of tape and oxide strands behind the two spools, and the intermittant nature of the firmly attached binder right to the right of the splice. Also note the small chips of oxide all over the place.

Finally, we re-loaded the tape into a new shell as the old one was too contaiminated with shards of oxide and it was easier than cleaning the old one.

We were able to play this and interspersed with music the client didn’t want, there was a total of ten minutes of family voices that we were able to recover and then clean up in the computer. The tape had not been well recorded, either. One section required a 30 dB boost to normalize the level. Algorithmix Noise Free Pro did an admirable job of reducing the noise. Note in the above photo, the white splicing tape to the left side of the window.

Note, in the above photo, the colour of the pancakes on the hubs appears to shift. The oxide coating is probably dual layer (see notes below) and the brown side attaches to the base film while the black side faces the head. The colour shift in the photo is related to this and the angle of the camera. When handling the pancakes we didn’t see any noticeable damage as one correspondent suggested from heat.

I wonder how many other tapes will behave like this in the years to come. This was the worst I have seen to date. Others have reported similar conditions with some French Kodak tape from the 1960s, and some acetate tapes from the 1950s or 1960s.

Ben Torre emailed me some comments that help put this into perspective:

BASF FeCr and CrO2 tapes were among the best of the day, and the SK/SM housings were marvelous in the days when cassette machines had crappy mechanisms that never allowed for proper tape pack. (other than Nakamichi, of course) [You can see the SM feed arms in the second photo of the opened original cassette.] I’m guessing the one shown is early-mid 1980s vintage based on the label. These were good enough for Mobile Fidelity to use when they were selling 1:1 dupes done on JVC decks. (they used the CrO2 tapes.) They were not cheap. I have one they did of Pink Floyd’s Dark Side Of The Moon, and it sounds impressive for a cassette.

The FeCr tapes were dual-layer, so I wouldn’t be surprised if the two layers of oxide had different rates of expansion and contraction. Put them through enough heat-cool cycles, and you might see this. Only way to tell for sure is to do an accelerated aging test.

[As to the cause,] my money is on heat-cool cycles over a 20 year period. Shoe-box in the attic, or more likely a tape left near a heat source over the years. Not hot enough to melt anything, but hot enough to provide lots of dry heat for a long time. Might even have been from intense sun exposure in a window. Look at that tell-tale discoloration on the top of the label.

Don’t bet on [this being a one-off].

One other I can recall in the mid-70s. Memorex had a ferric cassette tape… I forget the designation… that after repeated plays started exhibiting dropouts. Sure enough, one look at the tape showed that the oxide was breaking off in chips from the mylar base….

I’ve also received several other emails on this post that confirm the dual-layer nature of this type of tape and also reminding me that it is a “Type 3″ tape. Type 3 tapes didn’t stay long in the marketplace and were considered quite fragile at the time.

Comments:

Mikkel Breiler Posted Apr 5, 2006 8:55 PM

This cassette I bet it not newer than 1982. I believe that the FerroChrom name was derived from AGFA patents which BASF utilized after their take over of AGFA in very early 80s to make the best tape available at the time – debate we can if Chrome will stand out as the overall winner, as Chrome tape held up better due to it being a one layer tape and the fact that consumers reluctance to adopt the new TYPE III formula (probably becuase it was competing with TYPE IV) we never saw too much development at the time to get a better tape from the manufacturers who wanted to push the media. But I will vote for Chrome.
The SM mechanism was popular because it worked, most decks back in the day had awful take-up capabilities and the Security Mechanism seemed like a straight forward solution to the problem.
So when AGFA was incorporated into BASF they took a tape type that they hadn’t developed themselves and added their – if I recall only type of mechanism that worked towards an even spooling – SM invention. And I believe were it not for all the diseases the TYPE III tape-infant had to endure the type might have survived longer – but personally either TYPE IV or TYPE III would have eventually won most ground.
I have some one or two AGFA FerroChrom cassettes and I believe two BASF FerroChrom cassettes. And also a Sony 7′’ reel of FrCr-7-550-BL tape, and I have them only for reference because I happen to have decks which allow for selecting such. Neither tapes in my collection display the problem seen here.
And I am surprised that the BASF tape had problems like the one pictured above. But as the patents were developed otuside of their lab this poor tape from BASF may be the results of poor management at lower levels where AGFA engineers and other knowledgable people did not receive enough credit for their pioneering efforts and were not allowed to continue to make even better versions of the TYPE III tape. Or hindered in doing so.

Now for the observed discolouring. I have seen this one several BASF cassettes of the early 80s, with the SM invention. And I must conclude that it is simply poor glue for the labels. This is not something only found with BASF tapes of bygone times, but something several brands have ocasionally exhibited. Though in my collection TDK, Maxell and Sony have never had the issue. I have more pre-recorded cassettes with this problem (and the glue drying out so the labels is loose/missing) than I have BASF or AGFA tapes with poor glue. But it may happen.
Storage is the key, and apparantly the brave little tape you got never stood a chance.

It does strike me as odd when BASF – knowing that the brand covers a lot of factories that produce this or that chemical and – would have enough ties with other companies to come up with better glue for labels than what we see was apparently the case. maybe this is just another anomaly we can chalk up to ‘management success’.

But not every company can draw a winner when several years on, one engineers idea that looked very effective, cost saving, and or which the marketing department found would be useful as a buzzword, became a wrong decision. Hindsight is always 20-20.

So the FerroChrom tape had been out for a few years in its heyday, but when this baby hit the street either BASF was asleep at the factory or just did not bother too much with a slow seller which showed no improvement in the market, and poor storage just got the better of it.

Sincerely
Mikkel Breiler

Tony Amato Posted Mar 23, 2006 7:04 PM

These FeCr dual layer tapes were one of three brand formulations available between 1980 and 1986. Sony, Scotch and BASF were the 3 major players for Type III formulations. Dual layer configuration ~ top coat (layer) of chromimum dioxide over a base coast (layer) of ferric oxide. Great combination when you think of it ~ yet prone to drop outs when to subjected to climatic changes that can occur in an automobile or just general improper storage. Many considered it a low cost alternative to the then expensive Metal Type IV formulations that were emerging.

I still have a cache of Sony FeCr tapes recorded in the early 80’s ~ recordings of the Mobile Fidelity Beatles Collection vinyl. They have mostly survived due to careful storage, but some are now suffering from signal loss and a couple have begun to shed in similar fashion as the one depicted above.

Anyone having critically archived voice or music on tapes of this age, let alone tapes of this formulation, should seriously consider digital transfer before Oxidation and Age catch up and steal the recordings…

Tony

More from Tony on Apr 17, 2006 11:51 AM

With regard to the top of label, centered discoloration ~ It strikes me most obviously as natural oil/soil remnants from handling by a greasy/dirty set of fingers (more than likely build up over time) and then, subsequent aging, oxidation and environmental attack to an already weakened label surface. I’ve seen many a tape label look this way by way of friends who have massive tape collections and not a single sense of how to handle such a delicate product…

B77 Experience Posted Jun 4, 2006 10:29 AM

I recently bought a lot of still sealed BASF CSII from about the same time (a slightly newer model, but still a SM edition, with the large window).

The tape is perfect (typical BASF Chrome, no dropouts, good high frequencies, not too tolerant to hot levels), but the untouched labels exhibit dark spots all over (although they are distributed in a uniform area).
Strange enough, Side 2 is worse than Side 1 on all of the 4 tapes I bought. More glue, perhaps?
So, either a problem with glue or ink.

There has been a lot of interest in this issue recently and I’ve answered several people privately. Hopefully this location will make the work more accessible to all who are interested.

The general appearance of the Mark II. As you can see, I had the luxury of being surrounded by these great machines and so we sacrificed one with all the adaptations done by a great technician by the name of Noel McGinnity – we both agreed we still wanted it to look like an almost regular Studer! All the tubing has been adapted to withstand isopropyl alcohol and the IV drip bag does not leak.

I began working at Sound Archives/Nga Taonga Korero, which is a wholly owned subsidary of Radio New Zealand in 1994. My task was to preserve and digitize the entire NZ Composer’s collection to begin with. I was taught my skills “on the job” but was lucky enough to have the wisdom & know it all of several older broadcasting technicians at my fingertips.

It was whilst transferring this collection, which was all on reel-to-reel magnetic tape that I encountered SSS & lol, etc. My boss at the time, who had been a radio producer, told me to try using isopropyl alcohol with cotton sticks. So, my first method was to drip the cotton sticks into the iso and then, steadily, try and apply it to the tape, without shaking or moving. As you know, this chemical is NOT good to breathe in. Some of this audio was 2 track at 3 3/4ips on 7 inch reels. This was a BIG ask, as the fumes made me feel ill and dizzy at times. Unfortunately, my boss, at the time, was unconcerned about the dangers of me breathing in these fumes.

I had attempted baking the tapes first, as this was the standard, but had had little success with this. It really was hit and miss, and sometimes baking worked, but mostly, it didn’t. Sometimes, the tapes would play after baking for 24 hours and then sitting at room temperature for a week, or a day, but more often than not, they still would not play. Hence, the use of isopropyl alcohol. This always worked for me.

I began thinking that there had to be a better way of doing this in 1995, as the fumes and remaining steady was not easy. This is when I started thinking about using an intravenous drip bag. So, my trusty technician, Noel McGinnitty, and I got into making the first ‘prototype’ using an Otari which had already been redesigned to go at 1 7/8ips, 3 3/4ips, 7 1/2ips & 15ips. We removed the record head core and replaced it with piano felt. Please be mindful, that this was a crude first attempt. With the IV bag partially filled with Iso I then placed the syringe into the top part of the the felt and through trial & error, I adjusted the drip speed to 6 drips per minute. It worked! This meant I could multi-task and do data entries of the content whilst preserving the audio. This machine I called the “Mark 1″ version!

I then discovered that my IV bags were starting to go hard and at times, the joins would simply fall apart due to the glues used in putting these bags together. This was not a good thing as I was having Isopropyl falling onto the floor, plus I would have to quickly evacute my room because of the fumes! I saved all the parts from each bag that I could reuse – I am a firm believer in recycling. I got in touch with 2 chemical firms in Christchurch, NZ, and one of which specialized in medical equipment. The salesperson was so fascinated with my request he arrived that day to see for himself just what I was up to. He decided that the best IV bag would be one which takes the contents of a person’s stomach, which is very acidic. By the way, he gave me all this equpment for free, a rare thing! This worked, but I still had the problem of the glues being eaten away by the Iso.

In the meantime, I had already measured all the holes that these parts where falling out of. So, with the second company and after mch discussion I purchased lengths of silicone tubing of different diameters. I placed different types of tubing into ISO and left it for a year to soak. The silicone tubing came up trumps and was still flexible, unlike the others, which either broke, or simply disintegrated in my hands.

I made up several parts for the IV bags and attached them, or rather slipped them over the necessary holes. This did not require any glues and was a very snug fit. I had now solved the problem of the bags falling apart, a real breakthrough. By this time, the Public Hospital became interested and so we went through different types of syringe needles which didn’t have glues in them and finally found the most suitable.

By this time, I was wanting a more robust machine and most certainly a machine that the original recordings were recorded on. This was the Studer B67, prototype number 2 and known as the “Mark 2″. I had also conducted a survey of the reel-to-reel collections held at Sound Archives and found that at least 25% of the collections suffered from SSS & LOL. Strangely, unless the 10.5 reels contained splices, I found that they did NOT suffer from either ailments.

However, there were 2 brands, which I grew to really depise, on 10.5 reels that did suffer from SSS. They are AGFA PEM 469 ( I think) and PYRAL, which came on 10.5, 7 and 3 inch reels & made in France from my understanding. Both these brands you could stretch and the magnetic layer would just become dust. The PYRAL was also slightly too wide for the tape path and would let off a very thin layer as it progressed through to the take-up reel. These brands I preserved immediately as they were a priority. I understand in 1987 AGFA put out a world-wide plea to take on board fixing these tapes. Sound Archives sent their collection to Germany and it was done free. However, one broadcaster, who also happened to be management, did not send hers off and they were sent to us in the 1990’s. There were over 300 of them! Of course, I prioritized her recordings as to popularity and frequent access, which was mainly her!

The new Mark 2, some of you have seen photos of it. This machine, being a Studer, was treated with the respect due to this fine piece of machinery. It has sumps, still the piano felt (hand sewn by me in the inner unseen workings), an overflow sump with silicone tubing going into a container to catch any residual Iso, an inseen syringe needle cleverly welded into place and inside the felt, and re-designed ‘window wipers’ to take off the last of the Iso before it gets to the takeup reel. There had been a problem with the takeup reel being able to cope and to start with it would just stop, hence the window wipers, and yes, they are from a car!

I will be patenting my design as there has been a lot of interest in it. Some of this has been negative, but mostly positive. Richard Hess and I are like minded in that when a job needs to be done, you have to be inventive and sometimes, outside of the norm, to get the job at hand done.

These 2 machines are housed in New Zealand, one in the Christchurch office, and the other in the Auckland Maori Unit. I have an inkling that they have not been used since I left as I was really the only one who knew exactly what I was doing to get them to work precisely! Let me know NZ!

I have the makings of an intravenous drip bag with me, but back in NZ, I was lucky enough to have a plentiful supply of Studers as they were the standard machines, up until they went digital.

In this picture you can see that the record head core has been removed and has been stuffed with piano felt and a few trade secrets!

Drilled into the back of the record head case is tubing which goes through the machine and is attached to the IV bag.

Specially adapted “windscreen wipers” (yes, from a Ford Falcon or Zephyr!) which wipe away the excess isopropyl so that the take-up reel keeps an even tension and doesn’t slow down and stop like it did in an earlier model.

© 2006 Marie O’Connell all rights reserved.

Used with permission at http://www.richardhess.com/

THANKS, Marie!

For a current list of degrading analog tapes, click here.

There are multiple modes of degradation and it depends on the type of tape.

Acetate Tape

• Degrades through drying out (hydration has helped in some cases)
• Breakdown of the base through “vinegar syndrome” and possibly leading to total decompostion (although that has not been seen for tapes on any large scale)
• Damage from heat
• Damage from mold/fungus
• Loss of Lubricant is probably rare in acetate tapes. Few examples of it have been found.
• Freezing acetate tape (especially) is considered bad as many of the formulations included fatty-acid lubricants. Remember, this was from the 1940s and 1950s and one of the best lubricants of the era was sperm oil.

Polyester tape

• Binder hydrolysis (or sticky shed syndrome [SSS]) is the largest challenge faced with tapes from the 1970s-1990s. This can be partially reversed through incubation or heat treatment. While this link may not be complete, it is a great introduction.
• Loss of Lubricant (LoL) can be severe and can possibly be combined with binder hydroysis.
• Freezing is also not recommended for polyester tapes due to the potential of that tape also containing fatty-acid lubricants.

Obviously all tapes can suffer from mechanical damage and poor winds.

I expect to be discussing aspects of this in greater depth, but it is a complex subject and contradictory reports have been generated.