The Delay

The piece of equipment that delays and repeats a signal is called the delay. This machine records the input signal and delays it according to the setting of the time preset, reproducing it and giving a natural echo effect.
Initially the so-called tape echos were used, which are still used today to obtain vintage sounds. The signal to be delayed is sent to a recording head that records it on a tape. The signal is then sent to the reproduction head with the desired delay. The delay is obtained in two ways: varying the distance between the recording and reproduction heads, or varying the speed of the tape between the heads. Sometimes magnetic cylinders are also used. If using numerous reproduction heads at varying distances from the recording heads, multiple echos can be obtained.
The best quality echos obtained from tape are the warm sounds. However there are some drawbacks. It is impossibile to get a very short delay (in milliseconds), besides the fact that this type of equipment requires precise maintenance to work at its best. The heads must always be cleaned and demagnetized and the tape periodically replaced. You can therefore understand why we prefer to use the digital effects, whether pedal or rack. In the 1980's delay could be found only in digital rack equipment; the pedals were mostly analogical with few controls (depth, intensity and velocity). Today there are digital delay pedals with controls and characteristics similar to the more expensive rack instruments of the 80's. Lets look at a common programmable rack delay, which can also have pedal controls.

• Feedback. Basically adjusts the amount of sound with delay that returns to the input of the effect. In many equipment, however, this term is given to the control that regulates the number of repetitions of the note played (also called regen). The number of repetitions can vary from just one (setting the control to zero), to infinity (in the true sense of the word: a good piece of equipment is able to repeat the piece endlessly without any drawbacks). Disconnecting the effect or changing the program will block the delay.
• Delay time. Adjusts the time interval from the moment in which the note(s) is played, to the moment in which the delay begins working, which is the repetition of the note(s). The repetition of the notes will always have an interval determined by the regulation of this parameter.
• Tap delay. More and more this control is found on modern equipment. Connecting a foot switch to a special output, the delay time can be adjusted using the pedal. It is very useful to have the delay set with the time of the song on which you are playing.
• Delay level. Adjusts the mix level of the processed sound with the original sound. The higher the delay level, the higher the volume will be of that effect.
• Delay balance. This control is found only on stereo equipment and serves to balance the effect between the left and right channels. Some machines also have another control that continuously moves the sound between the two channels, very useful for obtainin particular environmental effects.
• Reverse. Not a very common control, but none the less interesting. Activating this you get one or more opposite repetitions. For example, if you are playing four notes (C - A - D - F), processing the signal with the reverse delay you will obtain a F - D - A - C response.

Examples of programming the delay

The delay is a commonly used effect, so therefore I think we should look at some examples of songs where the delay plays a fundamental role in the characteristics of the sound. To play these examples, you need to have good quality equipment where you can regulate the parameters indicated above. As a first example, lets analyze a pair of bars of the song Ballerina 12/24 by Steve Vai, from the Passion & Warfare album (1990). The sound was programmed on a Heventide H3000 in order to process the clean sound of the guitar adding two signal effects in stereo (delay and pitch transposer).



The guitar part plays in octave (transcribed in the first line combined to the tablature) with a metronome time of Quarter = 134. There must be two delays with a feedback of 0, each of which generates only one repetition. A first delay, programmed at about 112 ms, plays on the following sixteenth to the octave played (second line on the stave), while the second delay is set to about 224 ms and delays the signal by an octave (third line). The two delays are transposed with respect to the original signal by one sixth major (the first delay) and one quarter perfect (the second delay). The sum of all these notes gives a precise sixteenth in tempo, resulting in a surprisingly efficient sound.
It is possible to obtain this type of effect with many types of high quality equipment, such as the Rocktron Intellifex or Eventide H3000, using the delay parameters with the pitch control. The volume level of the effect has to be equal to the level of the original signal. Now lets look at some other examples of delay.




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