Slow Baked Mastertapes

[dave walsh]

I mention this because there are often threads here relating to "sticky tape syndrome" and restoration via [gentle] heating. Yesterday's Observer had a piece about some 2" mastertapes that were found in a hotel rubbish clearance at Kendal Rise in London. They were described as water logged and gooey. If played they would have been totally destroyed The content is a series of Master Tape recordings from Bob Marleys tour in the seventies, previously thought to have been lost forever. Out of thirteen reels, two were blank, one beyond recall and 10 that have been painstakingly [inch by inch] cleaned and restored via a session in the oven.

My son now lives in Edgware but is still involved with the Birmingham Music Scene. He is hoping that one of these recording will be an iconic Brum concert that they are still talking about there. From the details about the gentleman who carried out the audio archaeology, I suspect he may well be a Forum member. Recovering lost material like this-irrespective of whether it's my particular interest is always totally fascinating and interesting to me.

Perhaps related-on a recent birthday my son turned up with a copy of "When We Are no More" by Abby Smith Rumsey [ideal title if you are of a certain age like me]. It's about Digital Memory and Society/Archiving etc but there are some technical references including [p147] Carl Habers machine based on Particle Physics technology he developed at Cerne that can read Vinyl damaged or broken grooves in 2 or 3D without physical contact. It's called "IRENE" ie- Image, Reconstruct, Erase, Noise, Etc. He can be seen talking about in a very clear and concise way on You Tube and reminds. me a little of Richard Feynman. It's not audio tape he's working on I appreciate but it's probaly applicable there as well and fascinating. The past is the future! As for the Marley tapes? Well I guess the moral of the story is smoke less dope

Dave W

[Paul Stenning]

The story in the Telegraph (the first detailed one that cam up in a Goodle search)

http://www.telegraph.co.uk/news/2017...otel-basement/

[cheerfulcharlie]

I think that once the tape has been baked you have to act quickly to get the recording as the tape will now absorb moisture at a faster rate than before.

[Paul Stenning]

Yes, tape baking is a short term fix to allow the content to be copied off.

It is really impressive what can be done with enough time and patience. £25k for a year's work (albeit not full time) to do this is very reasonable. Although I am not a Bob Marley fan I do hope these recordings get released in due course.

It was mentioned at some length on the Today programme this morning, the tracks played seemed to me to be quite a bit faster than the album tracks. I used to live (mid 80's) quite close to a 'proper' reggae pub in Cambridge (the Devonshire Arms, Mill Road) where the sound system could make your eyeballs wobble. An entertaining night out, I can't listen to reggae now without the sheer impact of a huge system. Great times and listening to the clips today brought all sorts of memories back.

[dave walsh]

I don't know about eyeballs Merlin but there was a story about a south london techie who built reggae sounds systems [Dr somebody-not Who] in the seventies. It was said that he sourced the bass units from the company that supplied Lighthouses etc and when his massive cabinets were installed at a "house party" it was hard to get the people in. As you imply, attending one of those Reggae gigs meant you could feel the bottom end go through your body. Having also been at Flamborough Head when the Fog Warning sounded, I can believe these "urban myths". Those things could get down near the natural and fatal resonant frequency of the human cell structure ie 9 Hertz. Bottom E on a bass Guitar is close at 33 Hertz. Old style damp buzzing Tram Cables 16H-Health and Safety

Dave W

[TIMTAPE]

This short BBC interview gives some more detail as to what was done to the tapes before baking and finally playing them.

http://www.bbc.com/news/entertainment-arts-38878670

It's not uncommon for tapes - including family audio and videotapes - to become drenched with water, or worse contaminated water, and there have been people around for many years with the expertise to deal with them.
Here's one such company: http://www.specsbros.com/

I think it's a bit of an exaggeration for the article to speak of "modern technology" coming to the rescue. Actually it seems pretty basic technology but of course the work has to be done correctly and carefully.

The article also states the tapes were "believed to be irrepairable", giving the impression that the fellow who has now made them playable was doing something extraordinary. But it seems that for such tapes damaged in this way he just followed standard best practice, as he should have.

Also I wasnt aware that after baking a tape, it absorbs moisture "at a faster rate than before" (cheerfulcharlie). Certainly once the tape cools it will begin to reabsorb moisture and so it's advisable to transfer the contents sooner rather than later, but as to reabsorbing moisture at a faster rate I've never come across that. Does anybody else have any information on this?

Thanks, Tim

[jamesperrett]

Originally Posted by TIMTAPE

Also I wasnt aware that after baking a tape, it absorbs moisture "at a faster rate than before" (cheerfulcharlie). Certainly once the tape cools it will begin to reabsorb moisture and so it's advisable to transfer the contents sooner rather than later, but as to reabsorbing moisture at a faster rate I've never come across that. Does anybody else have any information on this?

My experience correlates with cheerfulcharlie's - if I wait more than a few days after baking a tape it may have become unplayable again.

[Ted Kendall]

There are several variables involved here - not least how sticky the tape was to start with, what the bake time/temperature/airflow figures were, and how old the stock was to start with. Certainly, tapes which would have been OK with an overnight bake a decade ago need nearer a week now, in my experience. My general practice is to start copying the day after I finish baking. I always used to reckon that the window was about six weeks, but don't rely on that now.

Incidentally, I doff my hat to the engineer concerned, not least for his sitzfleisch - I know from experience just how demanding such jobs can be!

[whyperion]

What temp do you bake at, and how do you avoid plastic spools melting?

[paulsherwin]

Engineers doing this sort of work generally build custom temperature controlled rigs. 'Baking' is a bit of a misnomer - you don't just shove them in the oven at regulo 6

[TIMTAPE]

Originally Posted by jamesperrett

My experience correlates with cheerfulcharlie's - if I wait more than a few days after baking a tape it may have become unplayable again.

Sure. Like you I always transfer the tape within a day or so of baking just to be on the safe side, and even then sometimes it needs to be rebaked, probably not so much because it has reabsorbed moisture but more likely because not enough moisture was driven out the first time. Apart from following the general rules of thumb I dont know of any way of establishing exactly when the tape has been baked enough.

[jamesperrett]

Originally Posted by whyperion

What temp do you bake at, and how do you avoid plastic spools melting?

Most tapes that need baking arrive on metal spools - Ampex did sell tape on 7" plastic reels which were mainly used with the small Fostex 8 track machines but I don't get many of these to transfer. The way I bake tapes is very gentle. 50 degrees is the maximum temperature I use and the temperature is ramped up slowly over a few hours. Plastic spools seem to survive this with no problems although, if I have a spare metal spool handy, I may transfer the tape to the metal spool anyway. I must say that the maximum temperature that I use has crept up over the years - the low 40's used to be sufficient so maybe that's the equivalent of Ted's longer baking time.

Ted also probably does this more often than me (I probably only do one baking session every 3 months) and will have his own recipe that works for him.