Effects and Signal Processors

In this section we'll be illustrating the principal sound-signal manipulation means and the relative machinery to this end. For convenience we'll refer to all the machinery in question with the word effect;, however pointing out a very important difference, namely, that effects can be divided into two categories: actual "effects" and signal processors. The ones belonging to the first category are those modules that carry out a manipulation on one part of the signal. Within these, the signal is divided in two, one part reaches the output directly, whereas the other passes through the circuit to then be manipulated. At the module's output, a mixer allows the two signals to reunite, one not having been manipulated (dry) and the other that has been manipulated (wet). The following is the electric scheme of the two sounds' composition:

Action of an effect on the signal

The characteristic of effects consists in the fact that the dry signal and the wet signal sum up in parallel. The ones belonging to the second category are the modules that on the other hand carry out a manipulation on the entire signal.

Actions of a signal-processor

In this case the modules are disposed in a series.

The evolution of electronics on a par with the intrinsic knowledge of sound, have allowed the tweaking of a series of circuits that have over time become indispensable in the practice of sound engineering. The evolution of digital electronics has further brought about progress in this sense, with the introduction of modules capable of manipulating the signal mathematically rather than electronically. At the moment the market is flooding with an infinite amount of different effects with all kinds of unimaginable finalities. Some of these are absolutely indispensable, others can be considered 'luxuries' to give an extra touch to ones work, others still are such particular effects that they can only be used in certain situations and are therefore of little use on a daily basis. All the effects referred to in this section can be attained through electric circuits, digital circuits that apply certain algorithms or through modules that combine the two aforementioned modalities. The electric circuits draw the signal supplied to them on input and they manipulate it by making it pass through apposite circuits that modify its characteristics (like amplitude or frequency-content). The quality of the module used in this case depends upon the quality of the single electrical components (resistances, condensers, inductances, connectors etc.) and by the quality of the circuit's project. Digital circuits operate in a completely different manner. The input-signal is sampled and memorized in a digital memory system (RAM). Thereafter, a digital circuit (made up of integrated circuits) carries out mathematical operations on the memorized data with an algorithm that simulates a real situation [Analogue effects simulation ] .

Lets then divide our effects in two categories: actual "effects" and signal processors. Next we'll be looking at a comprehensive description of both categories.