Ask Ralph : # 2 - How a tape was edited

[soulster]

It was so important to put the splicing tape on in line with the tape and not have it even a little 'diagonally off'. Any protruding edge of the splicing tape could catch on the guides of the tape machine and momenarilly affect the speed of the tape as it passed the record and play heads. That speed change could result in a sound blip or slurr.

Precisely! I did mention that.

Protruding splicing tape could also transefer some of the 'glue' onto the guides or tape heads, which would attract a build up of dirt or dust from the tape surface. Dirt on the heads could produce a muffled sound reducing the higher fequencies. [[That's why you were always encouraged to keep tape heads clean using cotton buds and meths or a specially made fluid.)

Again, correct! And, for examples of the extremes again, i've heard of recording engineers who would clean and demagnetize the heads before each pass! And, there is always the danger of running a tape too many times, usually in tracking, where the oxide can literally come off the tape. This actually happened while the Fleetwood Mac album "Rumours" was being recorded. Thank god they had a backup with the basic tracks on it.

There was also the danger of accidentally using a blade that had become magnetised. If you used one it would then magnetise the edge area of the tape you'd cut, which when played back would produce a bump or click type noise. [[Bear in mind that tape was a coating of ferric [iron] oxide on a 'plastic' backing. Recording worked by the tape heads transforming the sound you wanted into magnetic energy and magnetising the ferric particles on the tape. A magentised blade would introduce another unwanted type of magnetic energy.)

Right. The act of recording is that the record head, an low-power electromagnet, placed the magnetic particles into a certain direction on the tape with varying intensities. If you place a magnet, or other charged object too near the tape, it would change the properties of the particles, and that would cause an erasure or adverse sound.