Please note, there are very few nice, fluffy pictures...
We've been asked by many customers, many times, why recordings sound the way they do after many years of playing, for both vinyl and tape recordings.
We'll try and answer those questions here, and provide a bit more information besides, and we've broken the page down a bit to provide details on:
Unfortunately, what we've described in various places on this website as "wearing out" recordings by playing them - is absolutely true. Every time you play a vinyl record or tape, you irreparably damage the recording. If you use and maintain a top-quality stylus, and you ensure no dust or fingerprints, and you have an appropriate stylus and the stylus weight and bias properly balanced, and you've never washed the record, then the damage is limited; but the damage does occur, it's measurable, and it's irreversible. (Calling this natural physical degradation 'scaremongering', as some equipment manufacturers do is like calling 'aging' unnatural!)
Normally, this damage is almost undetectable. It's microscopic, for one thing, and unless you have an unlimited audio budget and perfect hearing, it's almost indiscernible in the short term. But the wear and tear is a long-term problem (like entropy), and by the time you notice the damage, it's past time to fix it. And for users who haven't changed their stylus every 50 hours, or people who can't get their cassette player aligned and cleaned properly, or who are using 20 or 30-year old equipment, the potential for damage is much higher, and the damage is more likely to be severe.
If you're interested in getting the best out of your turntable setup, please have a look at the Turntable Setup page on the RecordTech website. While not all the adjustments and descriptions are valid for all turntables, just knowing what adjustments can do what are really instructive!
..but I've seen pictures! Horrible Pictures!
And at the other extreme, there are some audio "professionals" who will demonstrate microscopic pictures of worn styluses that resemble lightning blasted tree trunks, or worn cassette pickups that look like a war zone, and in every case, they're trying to sell you something. Have you ever seen a high-magnification of a bedbug or mite? They're also very frightening, seen close up. But the danger, like the damage, is less than microscopically small. If you magnify the surface of a perfectly polished diamond enough, you'll see frightening crags and dangerous pointy bits, and you'd never think of putting that into your turntable's cartridge, right?
To be honest, we're selling something too - but what you get back from us isn't going to cost you anywhere like as much as the "magic" or "breakthrough" products these snake-oil sellers are flogging, and what we give you will (with care) last forever. That's got to be better than something you need to renew every couple of months, or that will cost you more than the rest of your audio system put together!
The decision of who and what to believe and why, is entirely up to you. So this page has been put up to give you all the information you need to understand what physical processes are at work when you play your recordings, what happens to your recordings when you're not able to play them, and to give you all the information you need to make your own decision about what you need to do to be able to go on listening to your favourite recordings.
But there's more!
While researching sites for detailed descriptions, images, and specifications that would help to explain the degradation of vinyl and magnetic recordings, we found so much information out there that it just didn't make sense to 'reinvent the wheel' here. So we've put together a kind of 'overview' of the physical processes involved in recording and playing back contact-type recordings, what this means for most common types of recordings that we're contacted about, what we do about those recordings, and what you can do to help minimise damage and decomposition of your recordings in the future.
We've also included a links page for reference to more detailed and technical discussion sites.
We hope this page helps to answer some of your questions, and gives you an opportunity to protect your recordings from further damage. If you have any further questions, please feel free to contact us by phone or email, or use our Contact Us form.
One of the main reasons modern CD (and, by extension, DVD) media was so quickly accepted as an alternative to vinyl and magnetic recordings is because there is no contact between the media (the CD itself) and the player mechanism. (Obviously, the disc has to be held at the centre to allow the player to spin the disc, but the actual recording surface is never actually touched during the playback process).
PLEASE NOTE: Although we're using the generic term 'vinyl' here, we're actually using that as a very general term that also includes other recording media involving a rotating platter - so when we say 'vinyl', we also mean 'Bakelite', 'wax', 'shellac', 'plastic', and any other groove-based recording media. Where the other types of media differ from vinyl, we'll specifically mention that. The same applies to 'tape' - the term covers reel tapes, cassette tapes, cartridge tapes, wire spool recordings, and so on. It just saves a whole lot of typing (and reading!).
There are a whole bunch of other reasons why CDs are technically superior in many (but not all) ways to vinyl and tape recordings (commercial recordings, anyway - specialist professional recording equipment is generally superior to the typical CD burning capabilities of most of us, but the problems described below still apply), but there are passionate and vocal supporters of both kinds of technology arguing the advantages of their (and the defects in their opponents') favourite recording methods. We're not going to get involved in the religious wars here, except to say that both camps have valid arguments. Of course, arguing which way a falling tree could be falling isn't going to stop the tree from falling, but it certainly helps to pass the time. (Please note that most of the discernible differences between CD and contact recordings can't be distinguished at all on the vast majority of consumer sound reproduction equipment - and certainly not on equipment costing less than a few hundred dollars! And we're not just talking about super headphones or super speakers or super amplifiers or noiseless preamps or gold cables or granite turntables - you need it all, not just one part, to notice, let alone measure, the difference! But the point is, there is a difference - if you can afford to hear it!)
Having said that... Comparing apples with apples, you will always hear more musical content from an analogue (vinyl or bakelite) recording than from a CD, and more from a CD than from typical cassette tape, and so on down the line. But hearing more is not the same as hearing it the way it was intended, and that's a whole new can of worms. Then there's high-definition audio DVD, and single-bit recording, which can sound at least as good as the original studio master; but these technologies aren't relevant in this discussion. Yet.
Where were we? Oh yeah...
The basic and fundamental flaw in 'traditional' recording technology (records and tapes) is that the players for these rely on physical contact between the media and the pickup mechanism in order to reproduce the recorded sound. From high school science, you'll (hopefully) recall that physical contact always involves friction. In fact, most of the technical advances made to record and tape recording and playback equipment (in the years before acceptance of CDs) involved trying to reduce or eliminate the amount of contact while still accurately reproducing the original recording's musical complexities.
We've mentioned vinyl and magnetic recordings as two different mechanisms, and now we'll explain why they are different. First, let's investigate how a vinyl record reproduces sound, then we'll look at a magnetic tape, and then we'll examine why recordings using these mechanisms need to be preserved in the future.
First, it doesn't really matter whether it's vinyl or plastic, shellac, Bakelite, gelatin, glass, or wax - the mechanism is identical regardless of what the record is made of.
Historically, wax and shellac were used at first (because they were the only materials that had all the properties needed), then Bakelite, since all these materials were cheap, had fairly well-known mechanical and chemical properties, they were relatively easy to form into a disc, and no-one had invented PVC (poly-vinyl chloride) yet. Once the technical and production advantages of PVC was recognised by everyone, it pretty much took over from all other recording materials. There were too many reasons why to discuss here, if you're interested, please check out the links at the bottom of the page. (We're pretty sure that there was a large and vocal minority who swore black and blue that shellac gave better sound reproduction qualities than PVC, and that PVC would damage your hearing, and so on and so forth - there are some anecdotal stories of this early technological inertia, but it's a fair bet that it took some time for PVC to become the disc of choice. Some things never change).
The studio recording, made on high-speed magnetic tape with multiple tracks (channels) is "mixed down" to just two channels (stereo), then is transferred to a 'master' disc by using the audio signals from the tape playback to move a cutting blade. The blade wiggles left and right in response to the sounds from one audio channel, and it jiggles up and down in response to the other audio channel, and meanwhile the blade is slowly moved across a rotating blank disc by a worm gear, so the recording appears as a spiral, moving from the outer edge of the disc to the centre. Since the master disc was fairly fragile (while it could be cut by a knife while it was warm, both shellac and Bakelite would shatter if dropped, and vinyl was still a little 'soft'), it couldn't be used to stamp out thousands of records without getting squished or smashed, so various means (cold silver electroplating and other clever designs using metallic deposits) were developed to create an extremely accurate metallic replica of this disc. The resulting metallic disc was called a 'mother' disc.
To create many thousands of saleable records, the metal 'mother' was basically pushed into hot, thin pools of shellac, Bakelite, and eventually, PVC, to make a record. There are more technical and detailed ways of describing this process, and from early recordings onward there are usually two sides to each record, and so on, but that's what the creation process basically boils down to.
Now, the resulting PVC (or Bakelite, or shellac, or plastic, etc) disc contains a very accurate replica of the grooves and wiggles created by the blade during the original recording process. Pretty darn clever, eh?
So, to play the recording, a small needle (old Bakelite recordings actually used real steel or bamboo needles, hence the name 'needle') or stylus, is delicately held within the grooves by a mechanical arm (the tonearm). When the record is spun around, the stylus follows the grooves, but the tonearm hardly moves at all, except to allow the stylus to follow the spiral pattern as the disc spins underneath it. The stylus wiggles and jiggles as it follows the groove around, and the wiggling and jiggling is amplified to recreate the original recording's sound.
Simple, huh? In fact, it's incredibly more complicated, as the up-and-down movements represents one part (or channel) of the recording, while the left-to-right movements represent the other - and there is always some 'interaction' between the two movements. So the actual groove is more like a 4-wheel-drive testing ground (see the images below for some great examples of what a groove in a record looks like, up close and personal).
Then there are entire industries (and their almost religiously fanatical adherents) involved in improving tonearm tracking (to start a fight in any record store, all that you needed was one person to yell out "Straight tonearm tracking is much better than S-type tonearm tracking!" and the fight would be on!), anti-skating mechanisms to prevent inner/outer groove wear (remember, the stylus is always moving towards the centre of the record, so it does wear more on one side than the other!), inertial mass damping (so the stylus was the only thing wiggling and jiggling, instead of the whole tonearm vibrating away), and on and on and on.
There are other, much more complex, issues involved with the type of recording, too. Bakelite, for instance, is urea-based, and mould and mildew just love to attach themselves to the organic molecules on the surface of such recordings. Then there's the issue of oxidation, which can cause a catastrophic breakdown in the surface structure of the recording, and playing such an oxidised surface with a badly-weighted or worn needle is like, well, scratching lines in chalk.
Many of these problems can be reduced, some can be almost eliminated, but they need careful, detailed consideration of the recording, the storage mechanism, and the cost is not trivial! Some universities in the US are conducting experiments to find out if lasers or computer imaging can be used to reproduce such recordings, and a laser turntable is commercially available; but despite some successes, there is much work to be done in this area, and the recordings that would most benefit from these investigations are literally crumbling away.
Looking simply at the primary reproduction mechanism (a needle pressing on a spinning disc), it's obvious that friction plays a significant part, both in terms of sound reproduction and wear and tear.
There are two main issues with friction involved in recording playback mechanisms. First, it results in wear and tear; and second, any material (even tiny amounts) that gets in the way of physical contact influences the amount and type of the contact, and never for the better.
Friction causes different (though related) results in vinyl record playback compared with magnetic tape playback, but the end result is the same - eventually the recording is worn out, and the original sound is badly distorted, or even inaudible.
Heat is one byproduct, microscopic scratching is the other. Both are increased when the record surface is dirty, and worn stylus tips can contribute massively to wear and tear. Remember, the actual contact area of an average stylus with the record in the groove, is around 80 µm², or less than a tenth of a square millimetre - and with some old stylus weights of up to 30 grams in some cases, that works out to many tens of kg per square millimetre of force - all on that tiny little needle! So it's not entirely surprising that stylus wear and tear (and groove wear and tear) is a major problem with older recordings. Even much later in the recording era, many (if not most) mainstream commercial turntables used tonearms and stylus weights that, instead of providing the best sound reproduction on then-current recordings, instead were designed to ensure the stylus would follow the groove in a badly worn record - so people could play their older recordings without skips or repeats. This meant that unless the user re-weighted the stylus for newer, undamaged recordings, the stylus would just tear along the grooves on every record played, like a mad farmer ploughing along through walls and roads and... ok, the analogy breaks down there. But stylus weights, and stylus composition, were paid far less attention than modern consumers pay to audio reproduction characteristics nowadays.
Wear and tear also increases in high-frequency recordings. The problem with reproducing high frequencies (especially once modern, high-frequency, high-fidelity instruments began to make their appearance) is that the stylus has to follow very large, very sharp changes in groove direction. The stylus always has some inertia, and with heavy stylus weights, the stylus can't change direction quickly enough, and the sharp changes in direction tend to get worn and 'smoothed out' over repeated playings. This results in high-frequency sounds (like the sounds produced when we say 'ssss' and other fricatives and sibilants) being more distorted and 'hashy' sounding on older recordings. This kind of recording damage is extremely difficult to reduce and almost impossible to eliminate without affecting other audio frequencies. Also, the damage caused by wear and tear is very similar to the effects of high frequency recording, and in fact the damage can be so severe that the underlying musical information is lost completely.
Of course, this kind of damage occurs at all frequencies on the recording, but the wear and tear is much worse as the musical frequency increases.
Oils Ain't Oils...
Most record manufacturers were aware of these issues, and many began to include a type of lubricant on the record surface, which was intended to reduce wear and tear. Normally, wiping the record with a soft cloth is all that's needed to keep dust and dirt (and acids from fingerprints) away from the lubricant. But over time the amount and efficiency of the lubricant decreases, and wear and tear increases.
The reason we put oil in our car engines is to try and minimise the wear and tear caused by big metal bits banging and rubbing together - but we can't lubricate our recordings. Any sort of lubricant will tend to separate the record from the stylus - and that changes the sound. On the other hand, an oil that's thin enough not to impede the movement of the stylus also won't do much to protect the recording. The best lubrication is the one the manufacturers put in the original PVC composition.
This is where many folks go wrong with their cleaning of records : they wash the record, which certainly removes most of the dirt and acids- but it also washes away the original lubricant! So the first play after cleaning sounds brilliant - but since there's no more lubricant, both the recording and the stylus are running 'dry' - which is a terrible thing. Imagine draining all your engine oil from your car, and washing out the oil galleries inside the engine with detergent, then not replacing the oil! Yes, the engine is sparkling clean. But how long will it run before it seizes up? The end of the driveway? We're not saying record lubrication is the same as vehicle lubrication, but in both cases the lubrication is there for a reason, and it needs to stay there!
It's generally not possible to "re-lubricate" any recordings with any kind of hydrocarbon-based lubricant, as these will at best interfere with the reproduction of the recording, and at worst will attack and damage the vinyl (or more especially Bakelite and shellac, since these are partly hydrocarbon-based compounds).
Tape playback is a completely different kettle of fish.
Tape recordings work by changing the orientation of magnetic particles (made from extremely fine metallic oxide particles) embedded in a matrix (called a 'binder' - think of fruit in jelly) stuck to a tape, then reading the orientations of the particles back (during playback). So it's a very different process to vinyl LP playback in that respect. (See the image below for a 3-dimensional view of a typical tape structure).
The issue of wear and tear with tapes is similar to LP playback though, in that the magnetisation of the tape is extremely weak; so the readback head must be very close to the magnetic material to detect the tiny changes. This means that the tape must be in contact with the actual head; and since the tape has to move to bring the rest of the recording under the playback head, it rubs against the head. The main difference here is that the tape contact is spread over a very wide area, as opposed to the tiny points of contact of the stylus.
The read heads, because they are in contact with tape for much of the time, also get worn. There have been a number of exotic and wonderful materials used by manufacturers to try and reduce the head wear. Glass, crystal, rare earth metals, plastic, and carbon (and strange and wonderful combinations of these compounds, like Hitachi's "Glass-Crystal-Ferrite" heads) have all been used to try and reduce the head wear, and reduce friction. The problem is, if the head isn't wearing out, something must be - and the only other thing that can wear is the tape itself.
Most tape manufacturers place a film or lubricant on the surface of the tape itself, on top of the magnetic material; others place the magnetic material on the back of the tape. In both cases, the lubricant will eventually wear out, although it's generally rated for more than one hundred passes over the tape heads. The problem is exacerbated if the heads themselves are worn, since then, no amount of lubricant is going to prevent the heads from damaging the tape surface, and if it's a favourite tape, this will happen over and over again.
This is the main reason why tape heads should be cleaned as often as possible - and more importantly, as carefully as possible! It's no good cleaning your tape heads with anything harder than whatever it is they are made from - otherwise it's not cleaning, it's more like grinding! Using old cleaning materials is even worse - contaminated cleaning equipment will never clean properly, and in most cases will cause more damage than not cleaning! So clean often, and clean carefully! Don't forget to clean the tapes, too - it's a bit pointless cleaning the heads and tape rollers if the next tape to go in is covered with grit and dust and moisture! You'll need to be much more careful cleaning the tapes, as most solvents that work with tape heads, don't work with tapes or the soft rollers. Make sure your cleaning compound is specifically rated to ensure no damage to rubber, mylar, and plastic.
Sticking to the story
The other issue with magnetic tape recordings is that the magnetic material used to record the magnetic fluctuations isn't actually a very good substance in terms of tensile strength. (Metallic oxides have a similar consistency to fine talcum powder, which is fairly difficult to stick together in a single long stream!). So the magnetic material is glued to a backing layer of mylar or other plastic. That's the tape bit. (Refer to the image above).
The problem is, the magnetic material tends to fracture when it's stressed - and it's always stresses as it's wound on to the spools at either end of the tape. Eventually, no matter how clever the makers have been with their glue, tape, and oxide formulations, the oxide part of the tape starts to break along tiny fracture lines. Normally this isn't a big deal, since the tape is essentially flat when it passes next to the read head. But with repeated plays, the fractures become larger and larger, making the flakes smaller and smaller, and more likely to stick to things other than the tape itself.
Meanwhile, the glue holding the oxide layer to the tape is decomposing. Slowly, to be sure, but inevitably the glue becomes more and more brittle. Now all of a sudden the fractures we were talking about become really important. In the worst case, the oxide comes free from the tape entirely - and bye-bye tape particles! With no magnetic material left in some patches, there is no audio possible - and nothing can be done to "repair" this kind of damage. So it's best to keep an eye on your tape recordings, and when they start to show some wear and tear (the tape looks 'bowed', or long horizontal streaks are visible along the length of tape), it's time to re-record or duplicate them if possible.
We aren't really trying to scare you. The processes described above for vinyl and magnetic recordings take place over many years, and happen at a microscopic level. It's not like you go to play a recording and suddenly it doesn't work anymore! The damage occurs, little by little, bit by bit, and you hardly ever notice it - until one day, you wonder where all the instruments have gone in your recordings, or why the backing vocals sound like they're singing in the next studio, or the volume fluctuates wildly, while the sound level swaps from left to right and back again.
And we haven't even started to mention scratches, breaks, heat damage, oxidation of the surfaces, vinyl decomposition, cigarette ash particles, moisture, fungus, mould, free radicals...
The fact is, your recordings need to be handled correctly, stored properly, and played on well-maintained equipment. That will significantly reduce the wear and tear. But it won't ever eliminate it.
This is the defining reason why Audiography exists - to take 'snapshots' of these recordings so they don't degrade any further. In most cases, we can fix (electronically) missing music, dropouts, skips, stutters, and scratches, without affecting any other parts of the recording. You can then store your recordings away, knowing that the recovered recording contains as much of the original music, and as little of all the noise and distortion caused by all the wear and tear, as is humanly possible.
We sincerely hope you found these descriptions and explanations useful (and accurate). If you have any questions, by all means, please feel free to get in touch with us and we'll do our level best to help you to protect your investment and our common heritage.
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