Tape Editing Techniques
An extensive step-by-step guide to correct editing.
Editing tape is an art best acquired through practice. If you want to splice coloured leader between songs, make tape loops or produce musique concrete compositions, then splicing is a necessary skill to acquire.
Today there are many mechanical aids available in the shops to help you splice tape. Most, however, are either toys or too expensive. The traditional metal splicing block and razor blade shown in Figure 1 are the most commonly used aids (almost an industry standard) to tape splicing and produce good clean splices at an economical price. The only disadvantage is that in order to obtain good results you need to practice quite a lot, but the reward is that you can produce some very interesting and highly accurate edits.
Before starting you will need to purchase the following items:
Splicing block (¼").
Single edge razor blades.
Three different coloured leader tapes.
White chinagraph pencil.
Sticky splicing tape.
Box of sticking plasters (beginners only!).
The editing block and razor blade have an obvious use. The chinagraph pencil is used to mark the back of the tape when you have located the sound. The sticky splicing tape is a special type which does not 'ooze' glue after a period of time - this is very important, Sellotape or similar products should never be used. If you don't use proper splicing tape the joins will stick to the adjacent layer of tape when wound onto the reel and over time will come apart. An edit you make correctly today, should last many years.
If you find it difficult to obtain these items from your local Hi-Fi or Electronics shop then try the addresses listed at the end of the article.
An editing block is made of a non-magnetic metal with a precision machined groove for the tape to lie in. Many sound engineers like to use their own personal block. This is because the tolerance of the groove varies slightly from block to block, and once you have found a good one it should last you a life time. Common practice in many studios is to glue the editing block onto the actual tape recorder (Figure 2).
Blocks normally have three slots running across the groove. The 45 and 60 degree angles are for normal editing. The 90 degree angle being used for editing stereo tapes (Figure 3), though it's only really necessary on low speed tapes. The reason for using a 90 degree splice is to eliminate stereo image shift, as a 45 degree splice would let you hear the right channel a fraction of a second before the left, which is undesirable.
The object is to locate a sound on tape and either remove it or splice in a piece of leader tape. To locate a sound eg. the first note at the beginning of a song, play the tape until you reach the start of the song and then stop the tape. Push the tape into contact with the heads by use of the cue lever.
With the tape against the heads, take hold of the spools in your hands and rock the tape from side to side until you home-in on the exact beginning of the sound. When you have located the sound, mark the back of the tape with a china- graph pencil at the point where the tape passes the playback head (Figure 2). When marking the tape do not apply too much pressure against the tape head. Alternatively, you can mark the tape at some other reference point ie. a tape guide. If you use another reference point don't forget to compensate for the difference on your editing block.
For the purposes of the explanation, we shall assume that you want to splice a coloured leader tape onto the beginning of the song.
After locating the start of your song and marking the point with the chinagraph pencil, cut the tape approximately 2 inches to the right of the mark. Place the tape into the splicing block with the mark positioned so that the 45 degree slot bisects it (Figure 4). Now take a length of leader and place it over the top so that it overlaps the slot by at least 2 inches (Figure 5).
Take the razor blade in one hand and place the forefinger and middle finger of your other hand onto the block either side of the slot. By applying a little outward pressure you can hold the tape securely in place and then cut it (Figure 6). The razor blade should be drawn across the tape at a slight angle, being guided by the slot. Don't force the blade downwards, if force is required to cut the tape this means the blade is blunt, time for a new one!
After removing the waste leader tape you should be presented with the sound tape and leader tape butting together. All you have to do now is cut a short piece of sticky tape (approx 1 inch) and lay it over the joint and then rub down the tape firmly to ensure that there are no air bubbles (Figure 7).
Once the edit is made, remove the tape from the block and inspect the joint. A good splice should be almost invisible, overlapping joints and gaps with sticky tape showing are to be avoided. When editing tape your hands should be clean and grease-free. Once you have acquired the basic skill of editing you can progress to more creative splices and enter the realms of Musique Concrete, if you so desire.
And finally, when editing tape it's worth while adopting a routine and sticking to it (excuse the pun). Every piece of tape that you remove should be marked with an arrow to indicate in which direction it travels. Don't throw away any pieces of tape until you've actually finished the job and you're satisfied that it's perfect,... you can discover some very horrible smells in the depths of rubbish bins when looking for tiny bits of tape!
TURNKEY (Contact Details)
CANFORD AUDIO (Contact Details)
Feature by Paul Gilby
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