Beginners Guide to Tape Recorder Basics

[ironbut]

This installment will be devoted to tape care. For most members who have record collections, some of the day to day precautions of vinyl handling will hold them in good stead when it comes to tapes. Direct handling of the oxide side should be avoided since the oils on your skin can attract dust and dirt and with some formulations, it can lead to shedding (the oils tend to be acidic). And leaving a tape on your machine and not in the proper box can lead to dust collection on the oxide side the next time it's played.
You may have noticed in the posts dealing with audible tape problems, almost all of them result in poor tape to head contact. This isn't a coincidence as magnetic fields decrease drastically with distance. You've found this out yourself if you've ever tried to put too thick a note on your fridge with a pizza magnet.  It's not just the extra weight that keeps it from holding, it's the increased distance for the most part. So when you hear a drop out, it's usually pretty broad band and much greater than the size of the dust particle would seem to warrant. Unlike a record needle which is forced to move by the dust itself, a drop out is that dust particle holding a portion on the tape (sometimes the entire track) far enough away from the head to make it sound like a momentary loss of signal (it's actually there but significantly reduced). So if your a vinyl lover, transfer those good habits over to your tape handling. If you're not, develop some. It won't take long before you don't have to think about what you're doing.
For much of this posting, I've pasted the "Tape Care Tips" page from US Recording Media;

    * Keep it clean: Playing tapes is a pleasurable experience. Your tape deck's heads, guides, and pinch roller(s) are on the front line of gently handling your valuable tapes. One thing that can mess up the gentility of  this process is dirt. There's a degree of static built up, especially in desert climates, on the deck as well as your tapes. The tape heads and guides must be kept clean, not only for sonic reasons but to protect the tapes you're playing. We've seen many cases where dirty heads and guides have scored (scraped) lines along the length of the tape, and especially the edges. It's important to keep these surfaces clean, for a tiny piece of oxide or other dirt stuck to the heads or guides can do quite a bit of irreversible damage to your precious tapes no matter how new or old they are. In particular, keep in mind the edges of the tape guides where the edges of the tape live must be kept clean. Many people use unwaxed dental floss to clean these tiny corners. If the edges of your tape are getting worn, you could have nasty tracking problems, because it's actually the edges of the tape that guide it through the tape path. And if these edges get wavy or scored, you could have some major problems. Se strongly suggest using our CL-100 head and guide cleaner to clean up these surfaces and our RC-5 for cleaning the pinch roller when needed. Oh, and No Smoking.
    * Check the condition of your guides and heads: Tape guide parts like lifters are supposed to be round, not showing a worn, flat spot. If there's a flat spot worn on any of your tape guides where there's clearly an edge that can be grabbed by your finger nail, they should either be repaired or replaced because the edges of these flat spots are very hard on tapes and can damage them beyond repair, especially in rewind or fast forward play. In some cases the guides can be turned in position revealing a new surface. Sometimes they can be sleeved with a stainless steel outer casing, and sometimes they have to be replaced. Some decks like a Revox A77 have rotating guides which is a good idea. Some decks like a Nagra have extremely hard surfaces, ruby in this case, and they are very resistant to wear, although extremely expensive.  Some decks have very hard stainless steel guides, but others have very soft metal, even brass which can wear more readily.
    * Demagnetize your Tape Path: Tape heads and guides tend to pick up magnetism from the tapes you're playing and rewinding over time. This magnetism can slowly erase the high frequencies on your tapes as well as create additional noise on playback/record. The magnetic fields can actually get strong enough to make proper calibration of your deck very difficult and make what should be quiet recording quite hissy. A good head demagnetizer like the RB Annis Han D Mag used on the entire tape path will eliminate these magnetic fields. It takes a fairly powerful demagnetizer like the Han D Mag to thoroughly erase these parts, as the small pencil type units simply aren't strong enough to demagnetize steel parts.
    * Make Sure Your Guides/Reel Platters are Aligned Properly: The tape guides, as opposed to the tape lifters which lift the tape away from the heads for wind functions, are the one thing on the deck that determines where on the tape heads the tape is going to travel. We've had so many cases where these guides are forcing the tape vertically into position because the reel platters are set too high or low on the tape deck. You might even see tape shedding at the left hand guide's edges. With very thin tape you might be able to see a distortion on one of the tape edges as the tape approaches   this first guide.  After playing through a tape, there should be equal distance from the top of the tape pack to the inside of the flanges on BOTH sides of the reel. This will show that the right side, or takeup, tape platter is at the proper height with relation to the tape guides and heads. If you rewind a tape, the same thing should happen on the left, or supply side, of the deck. Ideally after playing through a tape and flipping it over to the supply side to play the other side of the tape (assuming a 1/4 track recording) the tape should leave the reel in exactly the proper position to be lined up with the left hand guide without relying on this guide to force the tape into proper vertical position.
    * Just In Case: You may want to consider using a UPS, or uninterruptable power supply, on your open reel deck. Why? If you're rewinding a tape to play it and the power goes off, even briefly, it can be a mess. You can possible ruin your tapes depending on the transport.
    * Storing Temps and Humdity: All tapes, even video, should be stored vertically and in a dry, cool environment. Ideally for storage, keep them between 65 degrees to 69 degrees and a relative humidity of 30% to 45%. For very long term archiving, store your tapes ideally at around 50 degrees with a relative humidity of 20% to 30%. One big thing here is temperature and humidity swing which is very hard on recorded media. Humidity or temperature should not swing by more than 10% over a 24 hour period.
    * Never store your tapes horizontally: Always store your tapes in the played condition vertically. In other words, don't rewind your tapes and store them that way. You want to make sure the layers of tape sit directly atop of one another with no edges sticking out of the tape pack. These exposed edges are not only subject to damage but might even begin to get wavy due to the stresses applied to the tapes when used. This is especially critical when using thinner tapes like 1 mil or less.
    * Keep Away From Magnets: Do not lean your tapes against the side of electronics, especially of all things, loudspeakers. Keep away from transformers like those found in flourescent fixtures for high intensity halogen lights.
    * Erasing tapes: To save on unnecessary wear on your deck and to obtain the quietest erased tape possible, always use a good, high powered bulk tape eraser like the Verity VS250 or a tabletop model. You can't get as quiet an erase using the deck to begin with, so why subject the deck to unnecessary and costly wear?
Courtesy of http://usrecordingmedia-store.stores.yahoo.net/

How to tell something is wrong
Of course, when the sound seems distorted, muffled or just off is going to be the first clue. This could be the result of any of the adjustments on the machine, worn heads or downstream of the tape machine. If you have a headphone output or a dedicated headphone amp you can really eliminate some things quickly. I do all my adjustments with headphones since it makes changes in sound much more obvious.
Another thing to be on the lookout for is oxide shedding. You shouldn't be able to see oxide on the capstan, guides or heads after playing one tape. But if something is awry in the tape path (guides, reel tables, tension, pinch roller slipping, braking) the tape could be scrubbing or scrapping and releasing oxide. If you suspect one of these problems, make sure things are very quiet and listen to the tape as it makes it's way from one reel to the other. You should use a tape designated for adjustments, not one of your valuable Tape Project tapes. With your ear close to the machine playing the tape, use your finger and push the edge of the tape against the side of one of the guides so you will learn what it sounds like when it's scrapping. Then play the entire tape since some of these problems only appear when the tension is at a particular point.
Flanging This problem is related to the paragraph above. The reels themselves can become warped or bent and no machine adjustments will counteract this. Flanging is the rubbing of the tape against the "flange" of the reel usually on one spot on the reel. This will result in poor tape packs and can cause oxide loss in extreme cases. Be careful buying those cool looking aluminum reels off of auction sites unless they're too cheap to pass up. I've tried to straighten bent aluminum reels and never did anything but make them worse. There may be a way to do it but I'd rather just buy a couple new. It's a good idea to have two in case one gets bent or you want to change a 1/2 track tape from heads out to tails out.
Uneven wind This can vary from tape stocks or reel types. Unfortunately, there aren't any machines that will adjust themselves other than constant tension (some Studers). And some reels will not allow a nice smooth tape pack no matter what you do. So if you find one or two tapes with an uneven wind but the others are fine, try putting it on another reel before making adjustments. Some tapes with quality control problems (they do happen from even to the best manufacturers) may have been slitted (cut down from a wide roll of tape down to 1,2,1/2 and 1/4 inch) incorrectly and will rub and shed like crazy. The only cure for this is to return it.
High Frequency loss Boy, this is the catch all for tape problems. Almost every misalignment , worn part, and tape problem will have loss of high end sparkle.
All and any problem with reel to reel tape/machines should always be answered by first doing a thorough cleaning and then trying to repeat the problem. Many seemingly non related problems can be solved this way. It's easy and quick so why not?
So that ends the tape section of this primer and next we'll get into cleaning and regular servicing and a list of stuff you need.




Tape Timing Chart (Nominal minutes)

Reel

Tape

Footage

Speed [in/s (formerly i.p.s.)]

			1.875	3.75	7.5	15	30
5-inch	1.5 mil	600	60	30	15	7.5	3.75
	1.0 mil	900	90	45	22.5	11	5.5
	0.5 mil Double	1200	120	60	30	15	7.5
	0.5 mil Triple	1800	180	90	45	22.5	11
7-inch	1.5 mil	1200	120	60	30	15	7.5
	1.0 mil	1800	180	90	45	22.5	11
	0.5 mil Double	2400	240	120	60	30	15
	0.5 mil Triple	3600	360	180	90	45	22.5
10.5-inch	1.5 mil	2500	240	120	60	30	15
	1.0 mil	3600	360	180	90	45	22.5
	0.5 mil Double	4800	480	240	120	60	30
	0.5 mil Triple	7200	720	360	180	90	45

[ironbut]

Well we're finally at the point that we can start putting things together into something that works "in the service of music".
As the Tape Care posting indicates, keeping your tape heads and guides sparkling clean is hugely important. For this you'll need a cleaning solution and an applicator. If this is your first tape machine (open reel or cassette) you're probably in luck since for basic cleaning 90-99% isopropyl alcohol and Q tips will do fine. Of course it can't be just any alcohol or Q tips (don't use plastic handled ones since the plastic can scratch the head surface). Alcohol that's not labeled, as these higher concentrations are, contain lots of water. The problem with using water on your tape path is that even though a great deal of effort has gone into making the oxide surface of the tape as slick as possible, it's still slightly abrasive (as evidenced by head wear and flat spots of fixed guides). This freshly polished metal is the most vulnerable state for rusting. If you take a piece of steel and sand it's surface it will begin to show signs of rust in less than an hour. This kind of light cleaning should be done every ten tapes or so depending on the tapes that you've been playing. Most old tapes will shed loose oxide much more especially on their first couple of plays. So it's important to examine your tape path for oxide build up. On my machine it only takes a glance at the erase head to determine the amount of build up but you'll learn pretty quickly as you look at the amount of crap that collects on the Q tip. Every four or five times you clean the tape path, it's a good idea to use something a little stronger. I use the Lasermedia CL-100 US Recording Media sells (and mentioned above). Doc uses Naptha and there are other head specific cleaners too. One nice thing with these solvents is that you can use them to clean dried up grease if you're restoring the machine too (which takes a while with alcohol). With these solvents, after you clean a head or guide, it's a good idea to wipe it with the dry end of the Q tip to remove any excess. Allow these to air dry for at least 15 minutes before threading a tape since they'll destroy the binder of the tape (which is what they're supposed to do).

WarningBe aware that all "tape head cleaning solutions" aren't created equal. I use the CL-100 because it is recommended by US Recording Media but past that, I can't say that I know that it's the best thing for my heads or if it might be completely wrong for another type of head.
In any case, I recommend that you use it just for tough jobs and wipe any excess off when the cleaning is done.
Alcohol is what I use 99% of the time and only when that won't clean stubborn bits do I resort to CL-100.


By ironbut at 2008-08-25 photo courtesy of Richard Hess http://www.richardhess.com/tape/index.htm
Here's our old friend the Sony APR head assembly. If I was cleaning this with alcohol, CL-100 or naptha, the procedure is the same.
I keep these solvents in a cabinet in the bathroom just in case I spill it. I'm not really worried about the carpet or floor but these chemicals are very nasty (contain carcinogens) so if I spill it in the bathroom it can be cleaned and closed off till the fumes dissipate. It's also where the Q tips are.
You don't want to soak the Q tip or if you do, roll it on some tissue so it's just wet (I roll it on the toilet roll for a surprise for those special house guests).
With a strong light directed on the assembly, I'd start with the leftmost guide and clean the center all the way around if possible then direct the tip on the guide edges. The tape edges go all the way into these corners. So should you. Don't forget to wipe it with the dry end of the Q tip.
The heads on the left of the idler would be next and if the Q tip isn't dirty enough to transfer what's on it to the heads, you should be able to clean the timecode, erase and record heads. Clean all heads in the directions of tape travel. As you'll recall, heads are made of laminates stacked vertically so they have the equivalent of a grain that goes horizontally. All features of a head (relief slots, tracks) are also horizontally oriented and if  you were to scratch the head, (and you may not even be able to see this) it is less likely to cause an audible problem.
Go back to the bathroom and wet the another Q tip and clean the idler as you turn it. Be careful with any rolling guide like this since the solvent will clean the oil right out of the bearings and onto the surface that you're trying to clean so nicely. Clean the playback head and finally the last guide just like you did the first one. Well, not quite finally, that's just the head assembly. Your machine will have other tensioners, rollers or guides that are separate from the heads. The same procedure is to be followed. Just remember that if it's a roller, there's a bearing in there and if you don't want to have to pull it and re-lube it, keep the solvents out of the insides.  Discard used solvent supplies outside in the trash so no one has to breath the fumes except the flies.
So, what about the lifters and the tape sensor?
The lifters on this machine are ceramic and can be stained by solvents mixed with oxide (what do you think they make brown wood stain from?). Yours are probably metal so they would be cleaned in the above paragraph.  So that brings us to another esoteric cleaner. Formula 409. Anyone who remembers the Fantastic vs. Formula 409 wars of the 70's will have a favorite of these two and be equally sure that the other one's crap! For those who are too young to remember the blood stained household cleaners aisles of your local supermarket its just a water based all purpose cleaner. Squirt a bit on a Q tip and wipe clean all easily reached sides of the ceramic lifters and the optical sensors on the tape sensor.
If you're working on this machine or just new to it, clean the areas surrounding the heads and guides so you can tell if there is something that's making oxide shed. Every little clue helps. 409, plain water or even a dry Q tip will do depending on how dirty it is.
While you have the 409 out, wet a fresh Q tip and clean the surfaces of the pinch rollers. You just need to clean these most of the time but just like the heads, it's a good idea to use a rubber treatment a few times a year. I use some stuff from MG Chemicals called rubber restore but I already had a lifetime supply of this.
Here's a very important item to use before you think that you're done cleaning the head assembly. It's a magnifier of some type. I have a 10X lens from Swift that's small, cheap and clear. Get used to using one after those solvent cleanings and don't forget to check those corners ,.." I think I saw a potato growing in there!"  Seriously, it's very easy to get a glob of adhesive from a splice you didn't even know was there (I guess if it's oozing glue you'd be able to hear it though) or a drop of the champagne you and your spouse popped open when the last of your kids moved out.

Note The above discussion of pinch rollers (and some idlers and capstan surfaces) pertains to ones which are surfaced with rubber compounds. Urethane rollers/parts are becoming more common and they are not to be treated with chemicals meant to be used on rubber. I understand that water is recommended but it would be a good idea to ask the manufacturers if you have a particular problem that water isn't working on.

So what about demagnetizing? All these metal parts will become magnetized by the imprinted tape. It is very slight so demagnetizing just needs to be done a few times a year. It does require a strong demagnetizer and I recommend the RB Annis one that US Recording Media sells. They used to have a kit with a little meter that measured flux but I really think that if you use it with each coming season (four times a year) you'll be in good shape. Follow the included directions and turn off your machine before you begin. You can overload the outputs, destroy the movements in your VU meters and god knows what else (I've done it and it's loud!).


Next a shopping list

[ironbut]

This list is directed to all Tape Project subscribers. The sheet that's included with each release should tell the story; " Please make certain that your playback deck is in equally good condition before you play this tape.". The preceding post regarding the care and feeding of your tape machine should be followed religiously. Every one of these tapes are the results of a labor of love and are instant collectors items. I believe that they will be recognized as the highest standard of recorded media for the foreseeable future. Due to the limited numbers that these tapes will be produced in, each of them should be preserved for future generations of audiophiles. Of course these are yours to do with as you see fit, but if you choose to neglect them, expect a visit from a mylar clad intruder stepping out of his Hitachi Transport Module with the Temporal Foldback option holding a TP tape with your issue number on it!
So here's the basic list

1. Isopropyl Alcohol 90-99%
2.Q-Tips with wooden or paper sticks (not plastic)
3. Demagnetizer  (RB  Annis)
4. General purpose cleaner (409/Fantastic)
5. Head cleaner (the nasty stuff like naptha or LaserMedia CL-100)
6. Rubber preservative/restorer (several available but different so follow directions)
7. A strong light with a goose neck or easily directed. A bright little flashlight also helps.
8. A magnifier of some sort with a plastic frame (just in case you bump it on the heads)
9. Inspection mirror for examining heads/guides (try and find a small round ones with a penlight attached)

This list is for those of you who wish to do at least some of your machine servicing yourself.

1. Service Manual This is huge. Every machine is different in it's measurements and adjustments. Basic adjustments are usually the same from model year to model year but a service manual will often include pages that list any changes. If things don't look like the pictures or description, don't assume that they're the same. Studio machines in particular can have radically different components and even total redesign of entire areas. Previous owners may have done retrofits or upgrades which may have been ill advised or poorly implemented.
Anytime that things don't seem right, ask in one of the forums and even if none of us have first hand knowledge of it, we should be able to direct to somewhere or someone who does.
2. New non-magnetic tools. There are lots of things that you can do with basic tools. Screwdrivers, open end wrenches, sledgehammer (just joking), needlenose pliers. Don't use the ones that you pulled the tranny out of that panel truck with. Go to the hardware store and buy a new phillips screwdriver with a #2 tip. The parts for these machines are tough to find if not impossible. And even though pretty much all of us will have to do the "shake the chassis" dance a least once when a screw slips into the depths of your machine, patience will recover it with more certainty than a magnetic screwdriver. BTW, this is a dance best done with a partner, these things aren't light!
3.Tentelometer. A what?? This is a meter that will measure tape tension. Actually, this will be one of your most used tool when you do adjustments. The tape transport and head assembly is a system. Almost every adjustment you make to the transport effects tape tension so you'll use a tension meter with these adjustments. These are available for a fraction of their original cost off eBay. You have to have a service manual to know which of the many models that you need. The models and their ranges are listed in the price list on this link. There's also a pdf of the manual here;http://www.tentel.com/prod01a.htm (this is an early example of websites and very clunky to navigate so when you find what you need, save it!)
4. Scale for measuring braking and pinch roller pressure. There are a number of different types from the cheap plastic spring scales available from Edmund Scientific to nice German or Swiss made ones off of eBay. You may need 2 different ones depending on the machines specs but these measurements usually have a quite a bit of wiggle room so it it doesn't require the very best scale. Once again, you won't know which one to buy (weight range) unless you have a service manual.
5. Expendable reels of tape. This is one instance where I can heartily recommend purchasing blank tapes off of eBay. Buy a 10.5" and a 7" reel of tape to use exclusively for doing adjustments. Doing these requires relatively rough handling of tape and a Tape Project tape should only be used as a final test. I have one for brake testing and another for general adjustments. The brake testing one actually has a knot tied into it's end (to slip over the scale) and it's one of my early (and worst) prerecorded tape purchases.
6. Lubricants. There are many opinions on oils to use and depending on where it is used will determine the weight of the lubricant (oil or grease) For the most part, machines with parts that slide against each other should use a grease (I have some white grease called Phono Lube) and fast spinning bearings should have a light oil applied. I use an oil called Zoom Spout Turbine Oil that's available from many Ace Hardware stores. It was recommended on the Ampex list and so far I haven't got a problem with it. You should check your service manual to see what they recommend first. In many cases, whatever they suggest is no longer available.
7. Thick piece of high density foam for laying the machine on it's face. I got some 3 inch packing foam ( the white stuff) and made cut outs for levers, the head assembly, reel hold downs and tensioners so I can lay my machine face down without messing anything up (like all those adjustments you took days to perform).
8. Blue Painters tape, 1.5" wide. This is a low tack tape that really comes in handy. I use it to tape the foam (#7) to the machine, mask the paint on the faceplate when I use the tension meter (you'll find out when you use one that when you hit play, the tape will try and jerk the tension meter and the best way to use it will cause the pointed tape guides to hit the machine.
Of course there are any number of things you'll need like hex wrenches or test equipment but they're machine and/or job specific.

List for old prerecorded tape collectors
This list are things that you'll find helpful to maximize your enjoyment of these older tapes.
1. Pelon. This is a tape cleaning cloth that comes in 2" width on a roll. It's your basic cleaning material and contains traces of the lubricant that dries out over time. Great for minimizing drop outs. For tapes with just a few scattered drop outs, I just cut off a couple of inches and hold it against the oxide side on rewind (if there's any chance that the tape is brittle or otherwise delicate, try the film canister device I outlined in the tape problems post under drop outs.
2. Empty reels and boxes. If you collect old tapes for any time at all, you'll end up with some with useless boxes and/or wasted reels (bent, broken or just nasty). I think that everyone should have at least 2 empty 10.5" aluminum reels for transferring tape. Doc says that the low torque (large hubs) 7" plastic reels aren't being made anymore so if you see some anywhere, post it, but I do keep at least five 7" reels around and at least 5 empty boxes too.
3. Splicing block/tape/leader. I'm a big advocate of the liberal use of leader at the beginning and end of tapes. It avoids so many potential problems that it just makes sense. Make sure and get some single edge razor blades too.

Almost all of the items on these shopping lists can be had from US Recording Media. The others can be had from the drug store and hardware store.
The splicing blocks aren't available from USRM but ATR Services has used ones for $25 (new ones are $69). There are also some ones I found by Googling splicing block for around $40 but you should go for a well machined block if you can. It'll last a lifetime (I've had mine for about 36 years).   [email protected]

[xcortes]

I finally took the time to read this thread carefully.

Fantastic job Steve!

Only problem is that you're scaring me. Every sentence I read I lean more towards sending my deck to Doc to make sure it's in good shape and towards building a hermetically sealed, climate and humidity conditioned dust free room for my deck and tapes.

[ironbut]

Hey Xavier, I'm glad you like it and thanks for the feedback. I have to admit that I haven't gone back and re-read any of the postings yet. I probably should to get a feel for the direction this "stream of consciousness" is heading.
I don't mean to scare you guys but I'm afraid that the odds are that a few of the subscribers to the Tape Project will unwittingly, ruin some of their tapes. I may have gone a little overboard on the warnings about all the little things that can damage a tape but since this is a beginners guide, I'd feel responsible if I was to leave something out and the result would be a wasted tape.
On the other hand, I've tried to take the reality of real world use into account in which members who read this will know what should be done even though it's not practical at all times to do this. For an example, I know that I should always store my tapes vertically but my shelving purchases are way behind my tape purchases. As a result, I've got close to 200 tapes stacked everywhere. What's even worse is that I'm working on a deal to buy a lot of up to 200 more! (Yikes! I haven't gotten around to listening to over a hundred that I already have.)
So, you get the idea. I think that developing good habits (just like with records) is the main focus of this thread. This does include;
1. A very careful and thorough examination of your machine every year or so. 
2. Keeping an eye out for tell tale signs of maladjustment (excessive oxide shedding, high frequency loss and the sound of the tape edges scraping the guides or reels).
3. Keeping your tape path clean.
4. Putting your tapes back in their box after listening to them.
Following these four items will keep lots of problems at bay. But you know me, why list four little tips when I can write the Encyclopedia Britannica!

[Ben]

One question here.   Tape hiss: Is it the tape,machine or snake in the other room.

[ironbut]

Hi Ben, it must be starting to get cold up there by now ( I lived in upper state New York so I know what real cold is)?
The tape hiss is really the noise floor of the tape itself. It's caused by the particles of oxide ( the smaller the better) and the machines ability to take advantage of the dynamic range of the tape. When I first started fooling around with magnetic tape, the signal to noise ratio was one of the main specs that folks looked for when picking a machine. The s/n ratio given was usually with a specific tape. Of course those specs were given for record and play. Todays tapes all have a very large dynamic range so there's more tape hiss from the master tape than from the RMGI 468 that our tapes are recorded on. A couple of the demos of the TP tapes that I've done have had a few guys that had reel to reel machines back in the 70's. They all commented on the lack of tape hiss on these demo tape I used. I have quite a few pre recorded tapes from the 60'-80's and the ones without any noise reduction have quite a bit of hiss. The older the tape, the more hiss they have. On the other hand, these early releases were meant to be the highest fidelity available at the time and most of them have excellent sound. I'm always happy to open a tape box and find that it's an acetate tape even though they tend to be very fragile and extra care is needed in handling them.

[Ben]

It is roasting here. I am face the sun here, and we are having the last hot days
of indian summer. So with tape hiss, I guess I just live with it. In wonder if it was
more of a problem in the 60's with tube amps, or today with the newer tube,speakers
that are coming out.
PS:I just remembered, I think I like it better than the hidden white noise added to CD's.

[steveidosound]

After my recent bad experience with whatever is affecting my Moody Blues quad Seventh Sojourn tape, it occurs to me that there should be a section here dealing more with the physical properties of tape as well as the machines. I still would like to know what you do about oxide shed, the infamous tape squeal which you have somewhat covered under tape and head lubrication elswhere, if sticky-shed affects any prerecorded or non back coated tapes, and an explanation of how to bake/dehydrate, when they shifted from acetate to polyester for prerecorded tapes etc., etc.
Other beginners and old timers might appreciate this as part of this section too.

[ironbut]

I can see that there is demand for some info regarding Sticky Shed Syndrome and cures for this malady. For those who haven't had the dubious pleasure of owning a tape with SSS, it's main symptom is squealing. This can be very loud and can be easily heard through your speakers as well as from the machine itself. The second symptom is the slowing and even stopping of your machine.
SSS is caused by binder breakdown. As illustrated in Dr. Bogart's link, the binder is the "glue" that holds the oxide to the backing. In the 70's, Ampex changed their binder to a new compound which had short molecular chains. Several other companies such as 3m/Scotch followed suit. Unfortunately, these compounds were latter found to become unstable after long exposure to high humidity. These compounds absorbed the water particles and the binders broke down and appear as a dark tar like substance. What is especially unfortunate is the fact that this new binder was used in their mastering grade products. Some consumer products such as Shamrock audio tape was actually "B" stock of these high end tapes. Ampex accepted blame for the problem and set about finding a cure. Tape Baking was found to temporarily fix SSS.
Here's a chart of the most likely tapes to have this and similar problems;

Manufacturer   Tape Type   Years Affected   Information Source

Agfa   PEM 468   pre-1990?   Goran Finnberg
PEM 469   pre-1990?   Cary B. Cornett
type 1 (cassette duplicator)   ?   Ben Torre
Ampex/Quantegy   406   1970s-mid-1980s (and later?)   Many
407
456
457
Audiotape   See Capitol Q15
Capitol   Q15 (an Audiotape formulation)   early 1980s   Howard Sanner
Quantegy   see Ampex/Quantegy
Scotch/3M   226   All   William F. Lund
227
806
807
808
809

This was found at the home page of the Ampex list. http://recordist.com/

The problem became most apparent when record companies began to pull out old master tapes to produce CD's . You can imagine the turmoil it must've caused when they began reissuing properties that they already owned and mining the goldmine that they knew that they had.
Ampex's Cure Like I said, Ampex realized that these short chained compounds were a terrible mistake and changed their binders back to medium length molecular chains (long chain binders were too gooey). They also came up with the notion of tape baking. Agfa's binders had a similar problem and an elaborate microwave system is recommended for their tapes. Their binder breakdown appears differently also.
There are several good sites for instructions on tape baking which I'll list. One very important fact that you should keep in mind with tape baking (which I hinted at earlier) is that it is a temporary fix. The idea is to prepare the tape for transfer to, currently, high resolution digital. A friend of mine has lots of one of a kind, multitrack tapes on Ampex 456 and after he bakes them, they sound exactly as they should but only for a few days to a week. There are other cures such as TP member Marie's alcohol drip treatment Studers and cold playing (could that be where they got the name from?) of tapes. There have been a few claims of permanent fixes but I've yet to see any evidence that it can be done (especially at a reasonable cost).
I've been a bit reluctant to post anything regarding tape baking because for the most part, I've found the problem to be pretty rare with the tapes I've collected. Out of the few hundred prerecorded tapes that I have, I haven't got a single tape with true SSS. I only have a couple of master tapes and several of them, I've never played so there could be a few hiding in there. But unless you have a number of tapes with this problem, and they're unique in some way, I don't think it's worth the effort just to listen to them a few times.
Of course there's nothing wrong with doing a little experimenting if you have a mind to. If so, here's a good link to using a dehydrator to bake your tapes;
http://www.tangible-technology.com/tape/baking1.html
BTW It's recommended that you get an accurate thermometer to use with any tape baking.

[ironbut]

To answer Steve's questions regarding oxide shed, just about any problems with a tape or machine adjustments can result in oxide shedding.
Older tapes are problematic in that they are subject to any misuse by the previous owner/s. Even when a tape seems to be fine on the first couple of plays, it can start to exhibit shedding in subsequent plays. The reason for this is that is usually because of poor long term storage. The oxide could be somewhat loose and the action of moving across the heads and guides can create enough friction/heat to release it from the backing even further. Sometimes the oxide loss will stabilize after a few more plays the same way that many old tapes will shed on the very first play. The only thing that I've found that helps oxide shedding is the use of a tape lubricant like the Last tape treatment. It reduces the friction and seems to stabilize the oxides adhesion to the binder/backing. I use it on almost all of my old tapes and have almost no shedding with them now. That reduces the frequency that I have to clean the tape path (although I do quickly check it after almost every tape). As far as I'm concerned, the only problem with Last's products (I use the head treatment all the time too) is the cost.
If you begin to notice oxide shedding on newer tapes (such as your TP tapes) it's probably a problem with your machine. Things will get out of adjustment no matter which deck it is or how well you take care of it. Heads and fixed guides wear and the grooves that the tape will eventually wear in them will scrub the edges of the tape and release oxide. Improper tension on pinch rollers (too high or too low) will either stretch the tape as the rubber deforms against the capstan from high tension or the tape scrubs against the capstan as it slips from low tension. Slippage can be heard as a veiling (smearing) of the sound. You should use the roller tension recommended in your service manual but I always do final adjustments of it by ear.
In summary, anything that stretches the tape or causes excessive friction can cause your machine to increase oxide shed. Tape formulations vary in the longevity of the binders no matter what the storage conditions are. With the exception of sticky shed syndrome, binders ability to securely hold onto those tiny bits of oxide for 30+ years as we rub it against metal parts (in stock form my Technics has 15 different surfaces that the tape comes in contact in play) is pretty good. Even the worst ain't that shabby.

[astrotoy]

Steve, this is really great stuff that you are posting. Although I've had R@R machines for over 40 years, I've never understood the details of how they work and how to maintain them. Thanks for all the fine work.  Larry

[ironbut]

Thanks for your words of encouragement Larry. Writing this "guide" has given me the opportunity to pull all those little factoids about tape, that I carry around in my head, into something that makes sense as a whole. It's also forced me to go out and check my facts. I've even gotten a couple of books on the subject! (I've only flipped through them so far but sadly, none of them could be called excellent or even that good so far) Thank god for the internet and excellent web sites like Jay McKnight's and Richard Hess'.
I have relied on personal experience to help fill in some of the gaps so some of these suppositions are on shaky ground. Once again I ask that experienced users review what I've written and PM me with items that need to be corrected. Even if something just doesn't seem quite right or I left out something important on the subject, either post it ( I can add a footnote and refer to your post in the original) or PM me and I'll edit the original post. I've tried to leave my ego at the door since this is an instructional guide so accurate info is essential!

[Ben]

Umm Still waiting for the 'How to thread tape on the reel' faq.
 

[ironbut]

Hey Ben, if I understand your question, I generally just use the friction of the layers to hold the tape onto the empty reel. That is, I never use adhesive tape to get the tape started. On large reels, I grab the loose end about 4 inches from the end and thread it through to the empty reel pulling out slack as needed. I lay the tape across the hub of the empty reel with a windage hole on top and put a finger on the tape through it. With my other hand I turn the full reel till the 4 inches of slack is under my finger with maybe a half inch to spare. If you don't pull in the slack that little bit can stick out and go tick-tick-tick against the machine which I find real annoying. Now comes the tricky part, I switch hands, securing the tape end (that half inch) with a finger and begin turning the reel. Just as the tape is about to put a layer over the end and my finger, I reach a finger from the other hand through the top-most windage hole and secure the tape just before the tape covers my other finger below and I pull it out of the way. This keeps the beginning of the pack nice and tight. With a little practice it only takes one manual turn to secure the end and you can let the machine take it from there.
Small reels don't take as much slack to get things threaded but, if the brake tensioning on your machine is high like mine is, once the tape is secured on the empty reel, I give the full reel a little help(manually pull out enough for a layer or two) as I wind the first layer over the end. The reason for this is that the brake torque is constant but the smaller reels have a much smaller hub. This results in high tension at the beginning, enough to stretch your tape. This is a huge reason for having plenty of leader on your 7" reels.
Some small reels have no windage holes. They either have a little slotted hole in the hub or nothing at all! With the slotted hole you have to pull an inch or two of slack through it and hold this slack against the reel with a finger as you turn the reel. After the end is totally secured, you stuff the slack into the hole. The ones that they expect you to use splicing tape to secure, I replace the reel. Once you've collected for a bit, you're bound to have a dog or two. If you're going to toss it, save the reel. This is a great place to use those.
Stuff like this can really make you feel like you're all thumbs at first, but after a while it becomes second nature.
Hope this helps.