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Techbot at 14:50, 8 December 2021

2021-12-08T14:50:09Z

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Techbot: /* Elements of Signal Processing for Synthes */

2021-12-08T14:47:21Z

Elements of Signal Processing for Synthes

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Techbot: /* Elements of Signal Processing for Synthes */

2021-12-08T13:34:53Z

Elements of Signal Processing for Synthes

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Techbot at 13:30, 8 December 2021

2021-12-08T13:30:38Z

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Techbot at 13:15, 8 December 2021

2021-12-08T13:15:46Z

← Older revision		Revision as of 15:15, 8 December 2021
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	==== Envelope, Dynamics, Articulation ====		=== Envelope, Dynamics, Articulation ===
	Another notable family of effects includes all the envelope, dynamics, and articulation devices.		Another notable family of effects includes all the envelope, dynamics, and articulation devices.
	Voltage-controlled amplifiers (VCAs) are meant to apply a time-varying gain to a signal in order to shape its amplitude in time and create a dynamic contour. They can be controlled by a high- frequency signal, introducing amplitude modulation (AM), but more often they are controlled by envelope generators (EGs). These are tools that respond to a trigger or gate signal to generate a voltage that rises and decays, determining the temporal evolution of a note or any other musical event. Usually, such evolution is described by four parameters: the attack, decay, and release times		Voltage-controlled amplifiers (VCAs) are meant to apply a time-varying gain to a signal in order to shape its amplitude in time and create a dynamic contour. They can be controlled by a high- frequency signal, introducing amplitude modulation (AM), but more often they are controlled by envelope generators (EGs). These are tools that respond to a trigger or gate signal to generate a voltage that rises and decays, determining the temporal evolution of a note or any other musical event. Usually, such evolution is described by four parameters: the attack, decay, and release times
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	==== VCA ====		=== VCA ===
	amplitude of a tone through a VCA, they are performing tremolo. Finally, if they are used to shape the timbre of a sound (e.g. by modulating the cutoff of a filter), they are performing what		amplitude of a tone through a VCA, they are performing tremolo. Finally, if they are used to shape the timbre of a sound (e.g. by modulating the cutoff of a filter), they are performing what
	is sometime called wobble.		is sometime called wobble.
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	==== Utility Modules ====		=== Utility Modules ===
	There are, finally, a terrific number of utility modules that, despite their simplicity, have a high value for patching. Attenuators and attenuverters, mixers, multiples, mutes, and multiplexers and demultiplexers are very important tools to operate on signals. A brief definition is given for each one of these:		There are, finally, a terrific number of utility modules that, despite their simplicity, have a high value for patching. Attenuators and attenuverters, mixers, multiples, mutes, and multiplexers and demultiplexers are very important tools to operate on signals. A brief definition is given for each one of these:

Techbot at 13:13, 8 December 2021

2021-12-08T13:13:19Z

← Older revision		Revision as of 15:13, 8 December 2021
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	If we want to play some music, sound has to be generated somehow, right? Then the first family of modules that we are going to tackle is that of the sound sources: oscillators, noise sources, and samplers, mainly. Oscillators are those modules that generate a pitched tone. Their frequency content		== Components ==
			If we want to play some music, sound has to be generated somehow, right?
			Then the first family of modules that we are going to tackle is that of the sound sources: oscillators, noise sources, and samplers, mainly.
			=== Oscillators ===
			Oscillators are those modules that generate a pitched tone. Their frequency content
	varies depending on the waveform that is generated. Historically, only simple waveforms were generated, according to the electronic knowledge available. Typical waveforms are thus triangular, rectangular, sawtooth, and sinusoidal. These are all very simple waveforms that can be obtained by a few discrete components. From simple designs come simple spectra: their shape is very straight and unnatural, thus requiring additional processing to obtain pleasant sounds. Their spectral properties are discussed in Section 2.8, after the basic concepts related to frequency-domain analysis have been discussed (Figure 1.5).		varies depending on the waveform that is generated. Historically, only simple waveforms were generated, according to the electronic knowledge available. Typical waveforms are thus triangular, rectangular, sawtooth, and sinusoidal. These are all very simple waveforms that can be obtained by a few discrete components. From simple designs come simple spectra: their shape is very straight and unnatural, thus requiring additional processing to obtain pleasant sounds. Their spectral properties are discussed in Section 2.8, after the basic concepts related to frequency-domain analysis have been discussed (Figure 1.5).

	~~8 Modular Synthesis~~

	Figure 1.4: Connection between two modules. The output of Module 1 is connected to the input of Module 2 by a TS jack. This way, the input voltage of Module 2 follows the output voltage of Module 1, and thus the signal is conveyed from Module 1 to Module 2.		Figure 1.4: Connection between two modules. The output of Module 1 is connected to the input of Module 2 by a TS jack. This way, the input voltage of Module 2 follows the output voltage of Module 1, and thus the signal is conveyed from Module 1 to Module 2.
	Figure 1.5: Typical synthesizer oscillator waveforms include (from left to right) sawtooth, triangular, and		Figure 1.5: Typical synthesizer oscillator waveforms include (from left to right) sawtooth, triangular, and
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	Noise sources also belong to the tone generators family. These have no pitch, since noise is a broadband signal, but may allow the selection of the noise coloration (i.e. the slope of the spectral rolloff), something we shall discuss in the next chapter. Noise sources are very useful to create percussive sounds, to create drones, or to add character to pitched sounds. Finally, the recent introduction of digital modules allows for samplers to be housed in a Eurorack module. Samplers are usually capable of recording tones from an input or to recall recordings from a memory (e.g. an SD card) and trigger their playback. Other all-in-one modules are available that provide advanced tone generation techniques, such as modal synthesis, FM synthesis, formant synthesis, and so on. These are also based on digital architecture with powerful microcontrollers or digital signal processors (DSPs).		=== Noise sources ===
			also belong to the tone generators family. These have no pitch, since noise is a broadband signal, but may allow the selection of the noise coloration (i.e. the slope of the spectral rolloff), something we shall discuss in the next chapter. Noise sources are very useful to create percussive sounds, to create drones, or to add character to pitched sounds. Finally, the recent introduction of digital modules allows for samplers to be housed in a Eurorack module. Samplers are usually capable of recording tones from an input or to recall recordings from a memory (e.g. an SD card) and trigger their playback. Other all-in-one modules are available that provide advanced tone generation techniques, such as modal synthesis, FM synthesis, formant synthesis, and so on. These are also based on digital architecture with powerful microcontrollers or digital signal processors (DSPs).
	1.3.2 Timbre Modification and Spectral Processing		1.3.2 Timbre Modification and Spectral Processing
	As discussed, most tone generators produce very static sounds that need to be colored, altered, or emphasized. Timbre modification modules can be divided into at least four classes: filters, waveshapers, modulation effects, and vocoders.		As discussed, most tone generators produce very static sounds that need to be colored, altered, or emphasized. Timbre modification modules can be divided into at least four classes: filters, waveshapers, modulation effects, and vocoders.
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	Waveshaping devices have been extensively adopted by synthesizer developers such as Don Buchla and others in the West Coast tradition to create distinctive sound palettes. A waveshaper introduces new spectral components by distorting the waveform in the time domain. A common form of waveshaper is the foldback circuit, which wraps the signal over a desired threshold. Other processing circuits that are common with guitar players are distortion and clipping circuits. Waveshaping in the digital domain requires a lot of attention in order to reduce undesired artifacts (aliasing).		=== Waveshaping devices ===
			have been extensively adopted by synthesizer developers such as Don Buchla and others in the West Coast tradition to create distinctive sound palettes. A waveshaper introduces new spectral components by distorting the waveform in the time domain. A common form of waveshaper is the foldback circuit, which wraps the signal over a desired threshold. Other processing circuits that are common with guitar players are distortion and clipping circuits. Waveshaping in the digital domain requires a lot of attention in order to reduce undesired artifacts (aliasing).
	Other effects used in modular synthesizers are so-called modulation effects, most of which are based on delay lines: chorus, phaser, flanger, echo and delay, reverb, etc. Effects can be of any sort and are not limited to spectral processing or coloration, so the list can go on.		Other effects used in modular synthesizers are so-called modulation effects, most of which are based on delay lines: chorus, phaser, flanger, echo and delay, reverb, etc. Effects can be of any sort and are not limited to spectral processing or coloration, so the list can go on.
	Vocoders have had a large impact in the history of electronic music and its contaminations. They also played a major role in the movie industry to shape robot voices. Several variations exist;		Vocoders have had a large impact in the history of electronic music and its contaminations. They also played a major role in the movie industry to shape robot voices. Several variations exist;
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	Figure 1.6: A CRB Voco-Strings, exposed at the temporary Museum of the Italian Synthesizer in 2018, in Macerata, Italy. This keyboard was manufactured in 1979–1982. It was a string machine with vocoder and chorus, designed and produced not more than 3 km from where I wrote most of this book.		Figure 1.6: A CRB Voco-Strings, exposed at the temporary Museum of the Italian Synthesizer in 2018, in Macerata, Italy. This keyboard was manufactured in 1979–1982. It was a string machine with vocoder and chorus, designed and produced not more than 3 km from where I wrote most of this book.
	Photo courtesy of Acusmatiq MATME. Owner: Riccardo Pietroni.		Photo courtesy of Acusmatiq MATME. Owner: Riccardo Pietroni.
	~~Modular Synthesis 11~~
	~~1.3.3~~ Envelope, Dynamics, Articulation
			==== Envelope, Dynamics, Articulation ====
	Another notable family of effects includes all the envelope, dynamics, and articulation devices.		Another notable family of effects includes all the envelope, dynamics, and articulation devices.
	Voltage-controlled amplifiers (VCAs) are meant to apply a time-varying gain to a signal in order to shape its amplitude in time and create a dynamic contour. They can be controlled by a high- frequency signal, introducing amplitude modulation (AM), but more often they are controlled by envelope generators (EGs). These are tools that respond to a trigger or gate signal to generate a voltage that rises and decays, determining the temporal evolution of a note or any other musical event. Usually, such evolution is described by four parameters: the attack, decay, and release times		Voltage-controlled amplifiers (VCAs) are meant to apply a time-varying gain to a signal in order to shape its amplitude in time and create a dynamic contour. They can be controlled by a high- frequency signal, introducing amplitude modulation (AM), but more often they are controlled by envelope generators (EGs). These are tools that respond to a trigger or gate signal to generate a voltage that rises and decays, determining the temporal evolution of a note or any other musical event. Usually, such evolution is described by four parameters: the attack, decay, and release times
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	Similarly, low-frequency oscillators (LFOs) are used to control any of these parameters. LFOs are very similar to oscillators, but with a frequency of oscillation that sits below the audible range or slightly overlapping with its lower part. They are used to modulate other parameters. If		Similarly, low-frequency oscillators (LFOs) are used to control any of these parameters. LFOs are very similar to oscillators, but with a frequency of oscillation that sits below the audible range or slightly overlapping with its lower part. They are used to modulate other parameters. If
	they modulate the pitch of an oscillator, they are performing vibrato. If they modulate the Figure 1.7: A linear envelope generated according to the ADSR scheme.		they modulate the pitch of an oscillator, they are performing vibrato. If they modulate the Figure 1.7: A linear envelope generated according to the ADSR scheme.
	~~12 Modular Synthesis~~

			==== VCA ====
	amplitude of a tone through a VCA, they are performing tremolo. Finally, if they are used to shape the timbre of a sound (e.g. by modulating the cutoff of a filter), they are performing what		amplitude of a tone through a VCA, they are performing tremolo. Finally, if they are used to shape the timbre of a sound (e.g. by modulating the cutoff of a filter), they are performing what
	is sometime called wobble.		is sometime called wobble.
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	1.3.4 “Fire at Will,” or in Short: Sequencers Step sequencers is another family of modules that allow you to control the performance. Sequencers specifically had – and still have – a distinctive role in the making of electronic music, thanks to their Figure 1.8: Advanced envelope generation schemes may go beyond the ADSR scheme. The panel of a Viscount-Oberheim OB12 is shown, featuring an initial delay (DL) and a double decay (D1, D2) in addition to the usual controls.		1.3.4 “Fire at Will,” or in Short: Sequencers Step sequencers is another family of modules that allow you to control the performance. Sequencers specifically had – and still have – a distinctive role in the making of electronic music, thanks to their Figure 1.8: Advanced envelope generation schemes may go beyond the ADSR scheme. The panel of a Viscount-Oberheim OB12 is shown, featuring an initial delay (DL) and a double decay (D1, D2) in addition to the usual controls.
	Modular Synthesis 13		Modular Synthesis 13


	machine-like precision and their obsessive repetition on standard time signatures. Sequencers are made of an array or a matrix of steps, each representing equally spaced time divisions. For drum machines, each step stores a binary information: fire/do not fire. The sequencer cycles repeatedly along the steps and fires whenever one of them is armed. We may call this a binary sequencer. For synthesizers, each step has one or more control voltage values associated, selectable through knobs or sliders. These can be employed to control any of the synth parameters, most notably the pitch, which is altered cyclically, following the values read at each step. Sequencers may also include both control voltage and a binary switch, the latter for arming the step. Skipping some steps allows creating pauses in the sequence.		machine-like precision and their obsessive repetition on standard time signatures. Sequencers are made of an array or a matrix of steps, each representing equally spaced time divisions. For drum machines, each step stores a binary information: fire/do not fire. The sequencer cycles repeatedly along the steps and fires whenever one of them is armed. We may call this a binary sequencer. For synthesizers, each step has one or more control voltage values associated, selectable through knobs or sliders. These can be employed to control any of the synth parameters, most notably the pitch, which is altered cyclically, following the values read at each step. Sequencers may also include both control voltage and a binary switch, the latter for arming the step. Skipping some steps allows creating pauses in the sequence.
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	~~1.3.5~~ Utility Modules		==== Utility Modules ====


	There are, finally, a terrific number of utility modules that, despite their simplicity, have a high value for patching. Attenuators and attenuverters, mixers, multiples, mutes, and multiplexers and demultiplexers are very important tools to operate on signals. A brief definition is given for each one of these:		There are, finally, a terrific number of utility modules that, despite their simplicity, have a high value for patching. Attenuators and attenuverters, mixers, multiples, mutes, and multiplexers and demultiplexers are very important tools to operate on signals. A brief definition is given for each one of these:


	• Attenuators and attenuverters. An attenuator is a passive or active circuit that just attenuates the signal using a potentiometer. In the digital domain, this is equivalent to multiplying a signal by any value in the range [0, 1]. Attenuverters, additionally, are able to invert the signal, as if multiplying the signal by a number in the range [−1, 1]. Please note that inversion of a periodic signal is equivalent to a phase shift of 180° or π.		• Attenuators and attenuverters. An attenuator is a passive or active circuit that just attenuates the signal using a potentiometer. In the digital domain, this is equivalent to multiplying a signal by any value in the range [0, 1]. Attenuverters, additionally, are able to invert the signal, as if multiplying the signal by a number in the range [−1, 1]. Please note that inversion of a periodic signal is equivalent to a phase shift of 180° or π.

Techbot at 13:10, 8 December 2021

2021-12-08T13:10:03Z

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Techbot at 13:08, 8 December 2021

2021-12-08T13:08:55Z

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Techbot at 13:00, 8 December 2021

2021-12-08T13:00:51Z

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Techbot: /* INTRODUCTION: Sound is ..... */

2021-09-07T14:32:49Z

INTRODUCTION: Sound is .....

← Older revision		Revision as of 16:32, 7 September 2021
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	=== 2. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Vibration1.html Vibration: Frequency and Pitch] ===		=== 2. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Vibration1.html Vibration: Frequency and Pitch] ===
	=== 3. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Vibration2.~~htmlVibration~~: Spectrum and Timbre] ===		=== 3. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Vibration2.html Vibration: Spectrum and Timbre] ===
	=== 4. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Magnitude.~~htmlMagnitude~~: Levels and Loudness] ===		=== 4. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Magnitude.html Magnitude: Levels and Loudness] ===
	=== 5. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Sound-Environment.~~htmlSound~~-Environment Interaction] ===		=== 5. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Sound-Environment.html Sound-Environment Interaction] ===
	=== 6. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/AcousticSpace.~~htmlBinaural~~ Hearing and Acoustic Space] ===		=== 6. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/AcousticSpace.html Binaural Hearing and Acoustic Space] ===
	=== 7. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Sound-Sound.html Sound-Sound Interaction] ===		=== 7. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Sound-Sound.html Sound-Sound Interaction] ===
	=== 8. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/SpeechAcoustics.html Speech Acoustics] ===		=== 8. [http://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/SpeechAcoustics.html Speech Acoustics] ===