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A summer of archiving…

Filed under: archival practices,project notes,scanning,still images — 2013-08-13 by Richard L. Hess — Last Edit 2015-05-03 by Richard L. Hess

This summer [2013], we have completed the project we described at the end of last summer. We began the summer of 2008, with Robert working every summer to some degree since. Michael split the work with Robert in 2009. More commentary below the graphic (UPDATED 2013-08-31) after the break.

Protecting the container: Heritage Building Fire Safety

Filed under: archival practices,history,infrastructure — 2014-04-14 by Richard L. Hess — Last Edit 2014-04-14 by Richard L. Hess

While this post does not specifically pertain to audio tape restoration, it does pertain to keeping originals and copies safe, especially in heritage buildings.

This article is prompted by a devastating fire in Aurora, Ontario, Canada, where I have lived for the last 10 years and also from 1981-1983. On Friday, April 11th, there was some roofing work being done on the 135-year-old Aurora United Church. Roofers were using hot tar and allegedly some sort of open flame. Humidity is not high in the winter and we had a cold one. The church roof structure (and much of the ceiling structure of the nave) was wood. Hot tar, flame, low humidity, wind, and very dry old wood do not mix well, and the results, sadly, were predictable. The church is now a ruin. The fire department spent 4-5 hours with up to maybe 7-8 master streams running into the attic and other parts of the structure.



Thoughts about 8-track cartridges…

Filed under: archival practices,project notes,Tape Aging — 2013-10-01 by Richard L. Hess — Last Edit 2013-10-01 by Richard L. Hess

I have just transferred three 8-track cartridges and I thought I’d share my thoughts about these transfers and what are realistic expectations for these cartridges. (more…)

Azimuth: Hows and Whys

Filed under: archival practices,education,matching head to tape,recording/mastering — 2006-09-27 by Richard L. Hess — Last Edit 2013-06-27 by Richard L. Hess

There is a recurring question as to what is the best way to set azimuth for playing a tape. Many people assume that using the test-tape alignment is best. Well, that makes another big assumption: The recorder used a proper test tape alignment. While that can be the case, it usually is not. (more…)

Mono and stereo cassettes

Filed under: archival practices,cassettes — 2008-05-22 by Richard L. Hess — Last Edit 2012-10-28 by Richard L. Hess

The format page for 0.15 inch wide tape has a drawing (click for large version) that clearly shows that mono cassettes have one wide track and stereo cassettes split this track in half and add a small guard band. Most mono cassette recorders follow this format. It turns out that the mono Marantz PMD201 uses a two-channel head and records dual mono. Most other mono recorders seem to follow the standard.

While this is a theoretical problem, few if any good mono recorders are available for reproducing these tapes anyway, so most of us in the domain transfer field use good quality stereo machines for all cassette transfer work.

UPDATE 2012: While it is often possible to sum the channels if the Dragon finds proper azimuth, on many low-quality tapes this proper azimuth is not achieved. Now that azimuth correction (at least the time delay portion) is available for a reasonable price in iZotope RX2 Advanced, I have found that after correcting for time delay between channels that I can now sum both (if they are worthy of it) and reduce the noise prior to applying the noise reduction plug-in. (more…)

Playing a squealing reel of Sony PR-150 tape using D5 (Decamethylcyclopentasiloxane)

Filed under: archival practices,Decamethylcyclopentasiloxane,project notes,Sony APR-5000,Tape Aging — 2012-10-01 by Richard L. Hess — Last Edit 2012-10-01 by Richard L. Hess

Today I worked on a batch of five Sony PR-150 7-inch reels recorded at 3.75 in/s in one direction, two-track mono. One of the five reels showed marked shedding during fast-wind/rewind (to get the original reel as takeup and to check the tape pack). Four of the five reels played fine. This one squealed horribly. I ran the tape up and back over the dispenser and then fixed it in position for running the tape over it during the playback session. Once again, D5, Decamethylcyclopentasiloxane, CAS Number 541-02-6 comes to the rescue. The lovely thing about D5 is that it evaporates.

APR-5003 with D5 dispenser

Is this better than cold playback? I don’t honestly know. Both work. This is easier if there is no reel machine standing by for cold playback (which there was not today). I keep a Nakamichi MR-1 in the refrigerator so it is ready to go when I need it. The Studer A810 I put in the fridge did not like it. The capstan motor seized up AND the heat output overwhelmed the refrigerator’s capacity to cool. I suspect the APR would also overwhelm the refrigerator’s capacity. Also, it is much easier to lubricate a reel than a cassette.


Speed variation with unmatched reels

Filed under: archival practices,reels — 2012-09-20 by Richard L. Hess — Last Edit 2012-09-20 by Richard L. Hess

I received an interesting question from a European tape user with whom I frequently correspond:

“Is there any speed variation when playing a tape with different hubs on the supply reel and take-up reel?”

And I replied:

You raise an interesting question. The easiest answer to this is simple:
There is a risk of speed variations throughout the reel if the tape tension varies throughout the reel.
followed by the corollary:
This effect is made worse if the condition of the capstan / pinch-roller system is degraded.
Some capstan / pinch-roller / constant-torque systems handle this better than others.


Capturing both directions of a half-track mono tape

Filed under: archival practices,matching head to tape,recording/mastering — 2012-01-06 by Richard L. Hess — Last Edit 2012-01-06 by Richard L. Hess

It is possible to capture both directions of a two-sided half-track mono tape in one pass.

The critical factors are:

  • Azimuth
  • Direction
  • Polarity


Playing full-track mono tapes

Filed under: archival practices,matching head to tape — Richard L. Hess — Last Edit 2012-01-06 by Richard L. Hess

About ten years ago, when I transferred the oldest tapes in the United States as part of the Mullin-Palmer collection, my good friend Don Ososke pressured me to use a full-track head for the project. I had started transferring these full-track tapes with a Woelke NAB stereo (two 80 mil (2 mm) tracks) head and recording both channels. When I obtained a Nortronics full-track head, the difference was night-and-day. The full-track reproduction sounded fuller, smoother, and quieter. There were no tracking problems to speak of that would cause azimuth wander large enough to create a “flanging” or “phasing” effect of in-and-out high-frequency loss. (more…)

Playback of NAB 2-track tapes on a DIN Stereo (Butterfly) head

Filed under: archival practices,matching head to tape,reels — 2007-09-12 by Richard L. Hess — Last Edit 2012-01-06 by Richard L. Hess

I received a query from Sweden today asking

I have a Studer machine with butterfly heads with which I’d like to reproduce
tapes recorded with normal two track heads. Theoretically, how much more noise,
in dB, would I get from playing the “empty” part of the tape?

Let’s look at the assumptions.


Slide Storage Warning – Airequipt 2 x 2 Slide File

Filed under: archival practices,photography — 2011-08-22 by Richard L. Hess — Last Edit 2011-08-22 by Richard L. Hess

Over the years, I’ve used various methods of storing 35 mm colour transparencies. Until 1992, I used mostly metal slide boxes, but I do have about five Airequipt 2 x 2 Slide Files which are a hard plastic. One of them was sitting on a painted steel shelf and I found some oozing degradation components that were oily/greasy and rust where the paint on the shelf was scratched (probably prior to the box being placed on it).

These boxes have bubbled to the top of the priority list. The interior and slides seem to be fine…for now, and the other boxes are showing little or none of the symptoms of the one (which is probably not the oldest). The slides in this box date from 1983, but the box is almost certainly older. The Logan and Brumberger steel files are, as expected, holding up well, but I am migrating the images to hanging slide sheets from Transparent Office Products. I suspect that I’ll end up with about 2,500 sheets with probably 16 slides/sheet on average…and that will fit in seven file cabinet drawers (2′ deep). These sheets were originally sold by Franklin Distributors until Transparent took them over about half a decade ago. I bought my first sheets from them in 1991 or 1992 and they are still doing fine. Some other alleged to be archival sheets from the same time did not do as well.

We are scanning all of the images as we move them using a Nikon Coolscan 5000ED with SF-210 slide feeder.

Peter Copeland Audio Restoration Handbook now available

Filed under: archival practices,audio,education — 2008-09-14 by Richard L. Hess — Last Edit 2011-08-20 by Richard L. Hess

I consider myself fortunate to have been one of many recipients of Peter Copeland’s generous assistance while working with some challenging tapes. I was saddened by his too-early passing in 2006.

The British Libary has now published his Handbook (click here).

Watch those insects!

Filed under: -general,archival practices — 2011-05-31 by Richard L. Hess — Last Edit 2011-05-31 by Richard L. Hess

OK, this is not directly related to audio, but three audio people I know have been bitten by insects this spring and have suffered greatly for it. One was bitten by a spider in California, one almost died from a flea bite in Texas, and another received a suspected spider bite in Pennsylvania…so be careful…you never know where nasty insects might be hiding…maybe even under a tape box!

If you are worried about what to do, a friend, though a staunch vegan, squashes spiders. Of course, certain spiders are good and eat other insects, so this is just another one of those tough decisions in life.

And then there is mold. A good friend’s life was cut short by interaction with mold, though he was a smoker much of his life, so I’m certain that contributed to it.

As my Dad used to say, “you don’t get out of this life alive”, but he made a good run for it, living until age 93!

Updates posted for “winding tapes for long-term storage”

Filed under: archival practices,reels,storage-care-handling,Tape Aging,video — 2011-02-17 by Richard L. Hess — Last Edit 2011-02-17 by Richard L. Hess

There was yet another discussion about winding tapes for long term storage. This time it was on the Society of American Archivists list. While it was focused on VHS tapes, where it was decided that it was more important not to leave the tape in the middle with active content exposed, some discussions of the mechanics arose and I have added them as comments to the original post, which is available here.

Winding tapes for long-term storage—a quandary

Filed under: archival practices,storage-care-handling — 2008-02-15 by Richard L. Hess — Last Edit 2011-02-17 by Richard L. Hess

In 2006, I wrote a blog post (here) called “Let Sleeping Tapes Lie: What to do with poorly wound tapes”. For years, tape experts have been suggesting that it is not as good an idea to rewind tapes as was originally thought. This was partially based on the fact that most rewinding in archives was done on the oldest, junkiest machines so as to not wear out the good machines. Unless rewinding is done on high-quality tape transports, it is indeed counter-productive.

We continue to receive poorly wound tapes and are able to play them successfully. So why the quandary now? The reason is that I read portions of another Bharat Bhushan book, Mechanics and Reliability of Flexible Magnetic Media, 2nd Edition, New York, Springer, 2000. Referring to several research papers he makes a compelling case that tapes should be rewound annually if subject to storage environment fluctuations and every 3.5 years if kept in a climate controlled storage area. (more…)

IASA TC04 Guidelines on the Production and Preservation of Digital Audio Objects available online.

Filed under: archival practices,cassettes,computer/data,digital,education,history,reels,Tape Aging — 2010-10-08 by Richard L. Hess — Last Edit 2010-10-08 by Richard L. Hess

The International Association of Sound and Audiovisual Archives (IASA) has released their landmark Guidelines on the Production and Preservation of Digital Audio Objects as a free web (HTML) edition, available here.

I provided some information for the listing of tape equalizations, and I find the compiled table (here) most useful.

Thanks to Kevin Bradley and the IASA team for their work in making this available. If you want a PDF copy, join IASA and it’s available.

MD5 Checksums bring peace of mind

Filed under: archival practices,data storage — 2008-05-04 by Richard L. Hess — Last Edit 2009-11-03 by Richard L. Hess

If you ever worry about a bit error happening to your files and not finding out about it, you should use MD5 checksums (or some similar method) to be able to verify that the file has not changed.

The general theory behind a checksum (or “Message Digest” = “MD”) is that it provides a unique 128-bit number for each and every file, based on its content. If one bit changes, the MD5 checksum (sometimes called “hash”) changes. The checksum is repeatable, does not permit discovery of two different files that produce the same checksum, and is non-reversible (i.e. you can’t create the content from the checksum). (more…)

Zoom H2 line input

Filed under: archival practices,computer audio,live sound and recording,recording/mastering — 2009-04-13 by Richard L. Hess — Last Edit 2009-07-27 by Richard L. Hess

The Zoom H2 HandyCorder is perhaps the lowest-cost digital recorder on the market that provides reasonable and useful results. While I have a Sound Devices 722 for my more serious work, I bought the Zoom to test it out to see if it could be part of a simple tape digitization system for archives on a budget who wish to do the work themselves. It does this reasonably well.

As with much equipment–and especially with lower-cost equipment–the performance specifications and the actual operational data is not published. There are reports of the H2 clipping on the line inputs in some of the reviews and it appears that a lack of understanding how the inputs were configured exacerbated that situation.

There is nothing wrong with the line inputs on the H2. BUT there are some caveats: (more…)

40th Anniversary of Apollo 11 Moonwalk and the loss of data

Filed under: archival practices,data storage,history,oral history,video — 2009-07-17 by Richard L. Hess — Last Edit 2009-07-17 by Richard L. Hess

There has been much discussion over the last few years about finding and saving original tapes of the Apollo 11 Moonwalk videos downlinked from the moon. There is also an exciting project going on to restore and digitize the Lunar Orbiter tapes from more than 40 years ago.

The Lunar Orbiter tape digitization folks have just posted a commentary that bears reading by all archivists who are holding tapes. You may link to it here. The main site is

NASA, in their press conference yesterday held at The Newseum, admitted that the original 14-track 1-inch instrumentation (IRIG) tapes that contained the slow-scan video direct from the moon were most likely recycled and reused for later missions. Apparently, over 350,000 reels of instrumentation tape were recycled by NASA over time. No one apparently thought to preserve the 45-odd reels of the original moon walk. (more…)

Sticky Shed & Loss of Lubricant

Filed under: archival practices,Tape Aging — 2006-05-17 by Richard L. Hess — Last Edit 2009-01-30 by

This post has been updated as:

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.

Another way to identify a tape with Sticky Shed Syndrome (SSS)

Filed under: archival practices,reels,Tape Aging — 2008-08-22 by Richard L. Hess — Last Edit 2009-01-30 by

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.

Transfer Recommendations

Filed under: archival practices,recording/mastering — 2006-03-08 by Richard L. Hess — Last Edit 2008-06-05 by

Remember, this transfer that you (or I) are about to undertake may be the last time (and hopefully the best time) that the original is transferred. Here are some suggestions: (more…)

Aligning a tape recorder

Filed under: archival practices,cassettes,recording/mastering,reels — 2008-02-02 by Richard L. Hess — Last Edit 2008-06-03 by

It seems some people new to tape are confused over how to align a tape recorder. This is the abbreviated version.

If you want to record on a tape recorder (and I do not recommend doing that these days as you’re just generating more tapes that will need to be transferred later) the first thing to do is get the playback correct.

  1. CLEAN the machine. (more…)

DSS and other compressed digital files in an oral history archive

Filed under: archival practices,computer audio,dss — 2006-08-17 by Richard L. Hess — Last Edit 2008-06-03 by

With budget limitations, it appears that oral histories are being recorded with little thought to their long-term preservation. While this appears to have been the case in the past as well, with purchasing agents buying the cheapest white-box tape that they could find, continuing this into the digital age needs to be reconsidered.

The cost savings in using bargain-basement digital speech recorders are offset by the labour required to reformat these files upon their receipt by an archive and also the fidelity of the recording suffers, and with fidelity, intelligibility also suffers.

DSS was an industry standard agreed upon by Olympus, Grundig, and Philips in 1994. (more…)

Can I destroy my originals after I digitize them?

Filed under: archival practices — 2007-09-20 by Richard L. Hess — Last Edit 2008-05-10 by

Jill Hurst-Wahl in her excellent blog “Digitization 101” asks this question and provides some good answers with reasons. You can read it here.

Digital storage file systems and topologies

Filed under: archival practices,audio,data storage,video — 2008-03-04 by Richard L. Hess — Last Edit 2008-04-15 by

Once again, an interesting post on Jill Hurst-Wahl’s Digitization 101 Blog. She started by discussing tape backup issues. In the comments, I discussed my solution of using multiple spinning disks. Another commenter, Ike, provided an extensive review of file system options and his opinions on what works (and doesn’t) for long-term storage. Ike’s comment is fascinating and has lots of food for thought. Here is the post. (more…)

TAPE Project Audio Tape Digitisation Workflow

Filed under: archival practices,reels — 2008-03-06 by Richard L. Hess — Last Edit 2008-04-15 by

The Training for Audiovisual Preservation in Europe (TAPE) Project has just published an excellent Audio Tape Digitisation Workflow document here. It is authored by Juha Henriksson of the Finnish Jazz & Pop Archive and Nadja Wallaszkovits of Phonogrammarchiv, Austrian Academy of Sciences. It is aimed at the newcomer but still addresses all of the major points without being overwhelming. (more…)

A solution to reduce spoking in old acetate tapes

Filed under: archival practices,Racal Store 4DS,reels,Tape Aging — 2008-04-15 by Richard L. Hess — Last Edit 2008-04-15 by

It appears that many old acetate tapes when played on high-quality audio recorders will suffer spoking when left in a play wind condition. I have discussed this problem here. Since posting that, I have taken one of my Racal Store 4DS recorders and removed the heads to save them from wear and now use that to re-spool any tape that shows spoking when played on a Studer A80, Sony APR-5000, or Studer A810. (more…)

Using the proper tools…and don’t try this at home!

Filed under: archival practices,Racal Store 4DS,recording/mastering — 2008-01-09 by Richard L. Hess — Last Edit 2008-01-09 by

I didn’t think I needed to write this post, but it appears that someone purchased a Racal Store 4DS Instrumentation Recorder at least partially because I mentioned it, hoping that it would work as a four-track recorder for creating music. (more…)

How to play 4-track 1.875 in/s tapes…

Filed under: archival practices,Racal Store 4DS,Sony APR-5000 — 2007-11-21 by Richard L. Hess — Last Edit 2007-11-21 by

I received a query from a gentleman in Europe about 1.875 in/s 4-track tapes. He was frustrated in finding a good machine for transferring them. Apparently, they have many of these tapes. Here are my suggestions.

Perhaps the easiest answer is to find a Studer-Revox C274 with low speed options. They were made.

Two other options. (more…)

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