I'm sorry, but I really cannot accept this. In all my years of recording, nothing remotely like the attributes you describe work like viruses.
The tape, as a medium only has one significant attribute. It can be magnetised. In fact, when I did my BBC interview in the 70s, it was something I got tested on, and messed up bias current questions. I had some training to do. It is perfectly possible to subject a tape to very high levels of magnetism in a bulk eraser, or with some types of portable demagnetiser. The key feature of the process as trained was to make sure the field decayed and did not simply cut-off. The peak level could be high enough to permanently (semi-permanently ) magnetise the head, and the tape guides if they were made of certain materials. Passing a good tape over a head polarised in this way would indeed reduce the field recorded on the tape - reducing the level and introducing noise. However, the tape content itself was damaged, but not damaging to other equipment. It was possible for a tape recorded to extreme levels of saturation to be impossible to erase, and the tape could magnetise the next machine played on it, but only at levels perfectly capable of being demagnetised in the next cleaning/demag service.
You cannot call this a virus. It's just something that appears to have virus like action, but physics wise, it's not, in any shape or form.
Tapes had magnetic saturation limits, set by the formulation and going too high could be unfixable. With magnetics, transfer is possible under certain circumstances. It is NOT a virus that stamps pops and clicks - this is just silly and based on making conclusions on what you hear, and then imagining the cause.
Demagnetisers worked perfectly well used properly. One of my teachers maintained that a badly magnetised head block could be sorted by applying the damag power virtually touching the head gap, then only turning it off when right across the room, then repeating three times, then three times on the other two head - so 9 in total on a three head machine. You're totally right that the problems appear to move from machine to machine, but ONLY when a tape recorded with total saturation is laced up and played for a time. By time, I mean maybe a ten minute playout of a saturated tape. That ten minutes will leave the recorder needing demagnetisation. Any other tapes played on it could well be reduced in level - as tapes get when played on a machine needing head and guide demagnetising.
Don't attribute this process to some kind of virus. It's plain bog standard degradation caused by magnetised heads and guides. Perfectly normal.
This was known in the formative years, and processes to deal with it established in the UK and US by the broadcasters and detailed in the manuals of the day. You are attributing things already documented, understood and managed as something they are not. This is dangerous practice and needs rectification. You have not discovered anything and your methodology is faulty. The tapes are NOT infected, they're simply magnetised and recorded on machines needing service, cleaning and alignment. Demagnetising was an everyday practice. Any over-recorded tapes would be spotted in lineup and a quick test would prove or not if they were consigned to the bin. A session in the bulk demagnetiser would possibly salvage some. The Leevers-Rich ones could inflict substantial field strength - but it was reduced to nothing over a period of time and did a good job of erasing tapes but leaving them neutral.
If you really threw the equipment away, that's tragic, but they were not infected, just magnetised - and with care and attention residual magnetisation is rarely unfixable. The BBC got rid of loads of old but serviceable equipment when tape was phased out - NONE I am aware of were terminally magnetised.
You've drawn an understandable, but very wrong conclusion from your observations. Sorry. I've been doing tape for over 40 years and this just made me smile.
Rob, thank you so much for your response, I felt like I should give you the respect of responding with a little more detail.
I have to applaud the fact that you have never personally witnessed this going on, and I certainly hope you never do.
You might be accurate that with proper maintenance and management, it could have PREVENTED this from going off the deep end, but I will still stand by the diagnosis.
Yes, you can damage tapes and decks through inadequate maintenance (which is specifically why it's even mentioned in the owners manuals) throwing in just the right circumstances of timing and exposure, you can end up with some virus worthy issues .
I'm shocked you would not believe these circumstances could result in what I have shared, knowing you have worked in a related field, but again, I think it's very niche things required to experience this
Yes you can magnetize tapes and capstans and heads, Magnetism happens to be the scientific method used for the system to work, understanding however that these magnetic levels are so low, that these problems are not common, adding the fact that in the early stages ones ear might not be able to realize what's going on, adding to the fact that they are completely unaware of how it started to begin with, and the fact of how, and that it spreads.
The reason I call this a virus is simply because it has all the necessary traits living up to the definition. No, it's not biological, no you can't see it with a microscope, and it's not computer based, so some would rule it out of the data catagory, so it must be in a class of it's own.
Virus, I'm following the 2nd paragraph on this because it is perhaps the closest.
- 1.
an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.
"a virus infection"
- an infection or disease caused by a virus.
"I've had a virus"
- a harmful or corrupting influence.
"the virus of cruelty that is latent in all human beings"
- 2.
a piece of code which is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data.
The code in this case would most likely be a portion of percussion, with very specific timing to strike the capstan, hundreds if not thousands of times in the same spot. it's not a question if that's possible, it's how common. I think that depends on the material played, and how often someone plays that material as well as soem specifics about that material itself, and it's safe to say that your personal experiences were probably not in that arena.
It is capable of copying itself by re-stamping that magnetic charge on every rotation of the capstan. Keep in mind, it's pretty tuff to get to this point, but once it's here, not even a demagnetizer will fix it. This eventually leads to multiple pops and ticks out of that timing, which later on leads to them stacking, and eventually can exceed the original volume of the original recording.
I'm not sure if I mentioned this earlier, this isn't a theory, or a hypothesis, it was observed for over twelve years.
Keep in mind that just because you have worked with recording gear doesn't necessarily mean your going to be unlucky enough to ever witness it, which additionally doesn't mean it's not real.
Clearly the recording level plays a factor, in addition to the timing, in addition to how much it's played.
A simplistic way to understand why this happens, I like to use the analogy of magnetizing a screwdriver with a magnet. Keeping in mind that the magnet is thousands of times stronger then in the way audio tapes work. Yes, you can magnetize a screwdriver with a magnet. Now can you take that magnetized screwdriver and use it to magnetize something else, In a very small way, YES. Sometimes after picking up screws with a magnetized screwdriver, the screws themselves become slightly magnetized. it's a fact.
A magnetic domain is a region
within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction. ... These are the ferromagnetic, ferrimagnetic and antiferromagnetic materials.
There are additional issues tied into this infection going on with tape deck designs that I have yet to delve into, but it just depends on how versed you are into the general theory of electronics.
Cassette tapes are made of
a polyester-type plastic film with a magnetic coating. The original magnetic material was based on gamma ferric oxide (Fe2O3).
It might seem harmless at this point, but a magnetic coating on one side, with a polyester coating on the other, again, in the right circumstances can cause some issues, and your going to have to look at the tape path to ideally understand the picture here.
When you have these components together in such a way, they are in many ways much like a capacitor, but missing some key points. Those points are they are not WRAPPED
ED tightly together, (they are at the ree when wrappedl, but the infection point in this way of infection would come from the recording head, which is not close enough to the reels) and we only have one dielectric and one conductor. This can still hold charges, but again, not as well.
Most capacitors contain
at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's charge capacity.
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