MAGNETIC MEDIA - REEL TO REEL & CASSETTE
I have used (and still use) a large amount of 1/4" to 2" reel and cassette tape media.
Here are a few hints for those who are new (or have forgotten) about using this old analog media properly
Much of the tape you will be offered is old, most is in fact very old - 50 - 60 years old in fact, it often needs love and attention.
GENERAL INFORMATION ABOUT THE TAPE PATH - Care and Loving your revered tape machine
ALWAYS periodically clean your tape heads
Inspect the heads for obvious scratching or oxide build up
You can use a cotton tip with just a LITTLE iso alcohol (70% is easy to get but it must be pure) on the tip. Lightly rub across the tape heads and look at the cotton tip to see how much oxide it is picking up. Dry it off with the other end of the cotton tip.
ALWAYS periodically clean your capstan/pinch roller
Particularly susceptible to ageing is the capstan (metal rotating shaft) and the pinch roller - the tape runs between these two components.
Being made of rubber, over time the pinch roller will slowly deteriorate and instead of being quite soft (when you squeeze it) it will go very hard and often will have a shiny surface. This pinch roller is critical to a nice steady pulling through of the tape and it is vital that it remains in good condition, both the rubber and the consistent thickness. If the pinch roller is not nice and evenly circular, you will hear speed variations or possibly tape "slipping".
Any foreign dirt or dust is going to create increased friction in the tape path, which the tape mechanism may or may not be able to handle properly - some do and some don't.
Personally I NEVER use anything with a hint of alcohol on the pinch roller - alcohol based cleaners will promote and speed up the hardening of the pinch roller rubber - something you want to avoid!
Try to use as gentle and neutral a cleaning solution on your cotton tip as possible, avoiding alcohol based products. Once as much oxide as possible has been removed, look at the rubber. If it is dull that's great. If it is still shiny, sometimes I will give the pinch roller a VERY LIGHT buffing with a very fine wet & dry paper, but it is extremely important to be very gentle and keep in mind that any buffing must be even around the pinch roller otherwise you could be creating "bumps" which will create speed variations, wow & flutter in other words.
In all likelihood, a new replacement pinch roller will be required in the medium term - plan for this.
Now about specific tape types:
REEL TO REEL TAPE:
First, the reel itself MUST be straight and true. No cracks and definitely no misshapen reels! If someone has stood on your lovely 10.5" metal reel and it is misshapen - it must not be used, it is useless.
Wherever possible, use metal reels - they hold their shape much better and are of course stronger/less flexible. Almost all 10.5" reels and SOME 7" reels are metal. 5" and smaller are commonly acrylic plastic.
All tape, especially an unknown tape, should be suspect before you use it.
Brand new, sealed or used - it doesn't matter, treat all magnetic tape with caution
The oxide binding formulation starts to fail after many years and in fact some tape types are notorious for "tape shedding".
You will soon know if you have a problem tape, you start to hear lots of squeaks as the tape is moving through the tape path and the whole tape path will most likely be horribly fouled with brown oxide from the tape. It is not a pleasant experience and I have spent many hours cleaning up machines that have been fouled by tapes with failed formulations.
If you have had the misfortune of this happening, you must then immediately stop using the tape and clean up the tape transport path before using the machine again.
If the tape was blank, throw it out - it is useless for recording (save the reel though if is in good condition)
If the tape has recorded material on it AND IT IS IMPORTANT IN NATURE, you can try "tape baking". This is a simple process of slowly heating up the tape to a very low temperature. The idea is that the tape formulation reconsistutes and you should get at least a few decent passes through the machine without tape shedding, hopefully enough to pull off the precious recorded material and transfer to a more stable media.
Tape baking is widely discussed online, search for instructions using Google. It is EXTREMELY important to undertake tape baking very slowly and carefully.
The process doesn't always work but in most cases it allows for important material to be lifted off the tape.
Tape baking is not a permanent "fix" and after a while it will begin shedding once again and keep in mind that every time some oxide comes off the tape backing material, some audio is lost forever.
First up - the plastic shell.
Often these are cheap and nasty - some you can get inside and others are welded together. The most common issue with cassette is the shell and lack of lubrication on the hubs and pulleys.
The shell MUST be in good condition. If the shell uses screws to secure the two halves, that is fantastic. If it is sonic or glued together then you can only get inside the shell by destroying it - this is a difficult thing to do when you don't want to damage the tape inside.
Cassettes were designed to be self lubricating - the two hubs and corner pulleys need to rotate freely.
Friction is the cassette tape's enemy!
However after many years this lubrication fails and this is often the reason to try and get inside the shell.
How do you know if you have a cassette lubrication problem? It will be obvious, listen for horrible squeeking noises and uneven playback speed as the tape has difficulty moving inside the shell. You can also hear this noise on fast forward or rewind.
SCREW TYPE SHELLS:
Undo the screws holding the shell halves together. DO NOT DISTURB THE TAPE INSIDE! Next I personally use a silicon spray to just dampen a cotton tip and wipe this lightly around the pulley shafts and hub central area - the idea is to reduce friction as much as possible. DO NOT SPRAY DIRECTLY ONTO THE SHELL!
NEVER apply too much silicon to the shell and absolutely keep it away from the tape itself!
If you have silicon residue on the tape and then run the tape through a machine, you will be dragging silicon all over the tape heads, guides and capstan/pinch roller - what a disaster!
PERMANENTLY FIXED SHELLS:
There is not a lot you can do with these other than to try and carefully open the shell halves and delicately remove the tape for transfer to a "good shell".
I see a few online suggestions about these shells, dabbing silicon here and there but quite frankly I value my machines far more than that and would never randomly apply silicon material anywhere near the tape itself - this is just inviting trouble - BIG TROUBLE!
With EVERY cassette tape you should REPACK THE TAPE as your very first action:
REPACKING CASSETTE TAPE
This is the first step I take will ALL my cassette recorded material, especially if it has not been played for a long long time.
Insert the tape in your machine and fast forward to the end, rewind back to the beginning - do this a couple of times. Often this will clear up any tape "binding" and get those moving parts inside the shell running much more smoothly.
All tapes that I sell have been repacked, to ensure the pancake is nice and even.