GRP Synthesizer V22 Analog Vocoder User manual

Grp Synthesizer V22 Analog Vocoder Rev 1.3
GRP SYNTHESIZER®
V22 ANALOG VOCODER
OWNER’SMANUAL
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
CONTENTS
1. WELCOME
1.1 OPENING AND INSPECTING
1.2 FEW SIMPLE SAFETY RULES
1.3 PROPER USE
2. WHAT IS A VOCODER
2.1 ANALYSIS
2.2 SYNTHESIS
3.0 VOCODER IN ACTION
3.1 WORKING WITH SPEECH/MODULATOR SIGNAL
3.2 WORKING WITH CARRIER SIGNAL
3.3 IMPROVING QUALITY OF VOCODER SIGNAL
3.3.1 VOICED/UNVOICED SELECTION
3.3.2 ADDING SPEECH HIGH PASS SIGNAL
4. FRONT PANEL - REFERENCE
4.1 MIDI SECTION
4.2 SPEECH IN SECTION
4.3 PREAMPLIFIER SECTION
4.4 COUPLING SEZIONE
4.5 SLEW SEZIONE
4.6 VOICED/UNVOICED SEZIONE
4.7 HI PASS SEZIONE
4.8 LFO SEZIONE
4.9 MAIN OUT SEZIONE
4.10 CONNECTIONS
4.11 MIXER SEZIONE
4.12 ANALYSYS - ENVELOPE FOLLOWER OUTPUTS
4.13 SYNTESIS - VOLTAGE CONTROLLED AMPLIFIER INPUTS
5. REAR PANEL - REFERENCE
5.1 MIDI IN CONNECTOR
5.2 MIDI OUT/THRU CONNECTOR
5.3 USB CONNECTOR
5.4 DC 24V-1.66A CONNECTOR
CREDITS AND CONTACTS
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
1. WELCOME
Welcome and thank you for purchasing the Grp V22 Analog Vocoder. Your device is a refined analog Voco-
der equipped with a rich configuration of 44 analog filters -24dB/Oct for performing all the classic opera-
tions that we are used to considering indispensable in a good Vocoder and much more, guaranteeing you
years of tonal satisfaction.
1.1 OPENING AND INSPECTING
After opening the box, check inside for the presence of:
• Grp V22 Analog Vocoder.
• Dedicated external power supply.
• Cable for external power supply.
•Two metal rack ears for mounting the Vocoder into a standard 19” rack cabinet.
WARNING! To rack mount the Vocoder using the metal rack ears, it is mandatory to use the supplied
screws. If you use the screws that hold the wooden side panels in place to anchor the rack ears, you’ll
run the risk of damaging the internal electronics boards. Grp Synthesizer is not responsible for dama-
ge caused by the use of screws other than those provided and recommended.
TIP: Keep the original packaging and all its parts in case you need to ship the Vocoder.
1.2 FEW SIMPLE SAFETY RULES
GRP Synthesizer's environmental policy limits the use of polluting materials (lead, solvents, etc.) to the mi-
nimum. According to current EU legislation, it is necessary to dispose of the GRP Synthesizer V22 in accor-
dance with local regulations on the disposal of electrical and electronic waste. Under no circumstances
should you abandon the product in the environment: this action is punishable by law, as well as a long-term
source of pollution. In order to avoid the risk of electrocution and/or injuries, it is necessary to carefully fol-
low the instructions given in the manual and in the following notes.
•Do not open the Vocoder for any reason. The removal or disassembly of any panel involves exposu-
re of the operator to potentially dangerous voltages. For internal interventions, contact only Grp
Synthesizer and qualified technical personnel.
•Do not remove any screws on the external panels of the device.
•Do not expose the Vocoder to rain, water splashes, excessive humidity, steam, dust, metal particles
or any other material that can penetrate inside the ventilation holes.
•Do not insert any objects other than the appropriate plug into the rear socket of the device.
•Do not expose the device to heat sources.
•Do not expose the device to excessive vibrations or shocks during operation.
•At the time of installation or use in hot and humid rooms following storage or transport at very low
temperatures, condensation can form inside and outside the device. It is therefore essential to wait
for this condensation to disappear before turning on the device.
•Always use standard and intact power cables. In particular, never interrupt the central conductor of
the plugs or sockets that connects the metal casing to the protective earth.
•Always check that the power supply conforms to what is written on the back of the device.
•Do not obstruct the ventilation slots with which the device is equipped.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
•In the event of severe thunderstorms, avoid using the device and disconnect it from the power sup-
ply and other equipment.
•Disconnect the device from the power supply when not in use for long periods.
•In the event of a fuse blown as a result of non-extraordinary external events, such as sudden chan-
ges or violent power outages, thunderstorms, etc., do not try to replace it, but have the device
checked by qualified technical personnel.
•Do not force the adjustment travel beyond the limits.
•Even if you are a rockstar, NEVER place containers with liquids that could spill inside it near the de-
vice.
•The device must be placed on a stable surface or, alternatively, it can be mounted in a 19 "rack ca-
binet using the two metal rack ears supplied and the two special screws for anchoring them;
do not use the screws of the wooden side panels, otherwise you run the risk of damaging the
internal electronic boards.
1.3 PROPER USE
This device is designed exclusively to produce audio frequency signals. Any other use is prohibited and
voids the Grp Synthesizer warranty. Grp Synthesizer is not responsible for damage due to improper use.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
2. WHAT IS A VOCODER
The Vocoder is an analog circuit conceived in the first half of the last century. Its operation is based on the
possibility of adapting the harmonic and energy content of a spoken signal called Speech or Modulator to a
second electronic signal - indifferently monophonic or polyphonic - called Carrier; in this way, at the output
of the Vocoder you will be able to hear the voice message expressed by the Speech and adapted over the
Carrier that becomes “speaking". The Grp V22 is an Analog Vocoder that starts from the classic circuits of
the last century and offers an enhanced version in full compliance with analog technology.
For properly work, the Vocoder simultaneously needs two signals identified as Modulator and Carrier; the
information contained in the Modulator is used to re-equalize the harmonic content of the Carrier in real
time; the latter, according to the taste of the musician, can be a signal generated internally in the Vocoder
circuit or received from the outside world. The operations with the Modulator and Carrier signals take place
in two separate stages of processing defined as Analysis and Synthesis.
2.1 ANALYSIS
In the signal analysis phase, the Vocoder circuit extracts from the Speech/Modulator spoken signal the
energy activity present within the different frequency bands. To do this, a bank of Band Pass filters is built
whose number and center-band frequencies are properly chosen to accurately document the spoken signal
(in Grp V22 there are 22 Analysis filters covering from 185 Hz to 7040 Hz: twenty Band Pass -24dB/Oct fil-
ters comprised between a Low Pass -24dB/Oct and a High Pass -24dB/Oct.
The Modulator/Speech signal received at the microphone input, or reproduced from a previous recording,
is then analyzed by the Band Pass filters and sliced into a number of slices corresponding to the number of
available Band Pass stages: the higher the number of bands analysis, the higher the quality of the signal
produced by the Vocoder; a good size analog circuit can have from 15 to 22 analysis bands; the Grp V22
has - obviously - 22 simultaneously operative analysis bands.
The received audio signals from each of the analysis filters include any active signal portions - band by band
- within the analyzed signal; in this way, if the Speech signal contains a sibilant or a confricative, it will be
easy to find more energy in the medium-high analysis bands rather than in the low ones; a vowel “o” emit-
ted by a male baritone voice will engage mainly the low and medium-low analysis bands.
The output of each analysis filter is connected to an independent Envelope Follower module, which tran-
sforms the slice of audio signal into a control voltage whose amplitude and movement are proportional and
corresponding to the activity and energy present in the band analyzed; at the end of the Analysis stage, the
Modulator/Speech audio signal is transformed into a group of 22 parallel control voltages that document
the activity and energy distribution in the original signal.
2.2 SYNTHESIS
In the Synthesis section, a second signal called Carrier which can be indifferently monophonic or polypho-
nic, generated internally in the Vocoder or received by an external source, is subjected to the treatment of a
battery of Band Pass filters of number and frequencies in the center of the band identical to those used in
the Analysis section. In this way, the Carrier signal (which is hopefully chosen to offer a full and equally di-
stributed harmonic content, e.g. a sawtooth wave or a white noise) is sliced by 22 filtering sections which
will produce as many partial audio streams but parallel to each other. Unlike what was done in the Analysis
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
section, all 22 filters (as in the case of Grp V22) will simultaneously find full energy to process because the
Carrier source was properly chosen to offer a wide and constant range of energy activity, while the Modula-
tor signal/Speech can vary its content depending on what is said (the “message”) and the age/gender of
the speaker.
The signal slices processed by the 22 Synthesis filters are connected to the inputs of as many Amplifiers,
whose output levels are placed under the control of the 22 signals produced by the Envelope Followers of
the Analysis section; the sum of the outputs of the 22 Amplifiers is connected to a summation point (a real
Mixer) and is subsequently made available for listening at the Vocoder output. In this way, the harmonic
content of the Carrier signal is re-equalized in real time using on the harmonic content of the Modulator
Speech signal. If the latter is a male voice that counts "one, two, three and four", at the output of the Vo-
coder you will hear the Sawtooth wave oscillator used as Carrier recite "one, two, three and four" with its
own intonation (and polyphony, if available).
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
3.0 VOCODER IN ACTION
While a top level quality analog Vocoder like the Grp V22 works better than a cheaper structure, offering a
better quality signal, it is always possible to enhance the functioning of the original circuit by resorting to a
few simple behaviors.
3.1 WORKING WITH SPEECH/MODULATOR SIGNAL
To make the Vocoder circuit work as well as possible, the Speech/Modulator signal must be suitably adju-
sted to offer a signal level as homogeneous and constant as possible (it is therefore necessary to carefully
adjust the level of the microphone input signal to the circuit); for this reason, the Grp V22 features two
SPEECH IN and PREAMPLIFIER sections which offer, in addition to the volume adjustment with direct con-
trol on the Vu-meter, also COMP(ression) and NOISE GATE adjustments. It is advisable, especially during
the musical production phases, to send Speech / Modulator signals previously recorded and properly sub-
jected to level compression/normalization to the Vocoder. For live usage, it is recommended to use headset
microphones capable of maintaining a constant distance between the mouth and the microphone capsule.
3.2 WORKING WITH CARRIER SIGNAL
To engage the 22 Synthesis bands in a homogeneous way, the signal sent to them must be as rich as possi-
ble in harmonics and energy; from this point of view, a simple Sine wave is the worst choice you can make.
For this reason, analog Vocoders almost always offer one or two oscillators that produce Sawtooth and
Square waves, notoriously rich in harmonic content; Grp V22 offers an analog oscillator that produces Saw/
Square with PWM, coupled to a White Noise Generator (more details below).
The simply filtering behavior offered by the Synthesis section is indifferent to the monophonic or even poly-
phonic nature of the Carrier signal: for this reason, the most characteristic musical applications of the analog
Vocoder see equally used many full-bodied Saw/Square wave analog oscillators used to generate robotic
voices, and dense chords played on external polyphonic instruments used to generate complex harmonic
textures. As it is easy to imagine, for using of the external Carrier signal it is mandatory to recommend accu-
racy in adjusting the input level and in choosing a signal with a harmonic quality/complexity high enough to
be active on the different Synthesis bands.
3.3 IMPROVING QUALITY OF VOCODER SIGNAL
Even if today the Vocoder is considered a musical instrument for the production of Electronic Music, in the
original intentions of its inventor the most important point was the guarantee of intelligibility for the signal
produced and the possibility of recognizing what was being pronounced. For this reason, a top-quality qua-
lity analog Vocoder must provide two essential precautions: Voiced/Unvoiced selection for the Carrier signal
and the capability of recovering a variable portion of the Speech/Modulator signal processed through one
dedicated High Pass Filter.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
3.3.1 VOICED/UNVOICED SELECTION
The Voiced/Unvoiced selection engine allows you to optimize the quality of the Carrier signal by smoothly
adapting it to the characteristics of the spoken signal received at the input of the Analysis section; when
pronouncing vowels or diphthongs, the Carrier must be sufficiently rich in acute harmonics, but must mainly
offer a good amount of energy on the frequencies normally used by human speech; when pronouncing
consonants - especially sibilants - the Carrier used must be much more active on the mid-highs. As it is not
possible to satisfy the two needs in a single carrier signal, it is necessary to automatically and safely alterna-
te two different analog signals optimized for their respective tasks: an oscillator that produces a rich tuned
waveform (Voiced portion of the Carrier signal) and a White Noise Generator that produces an energetically
rich signal of mid-high components (Unvoiced portion of the Carrier signal).
In this way, by pronouncing the word"sector", the Voiced/Unvoiced selection circuit will subject the recei-
ved Speech/Modulator signal (the word "sector") to a comparator that weighs the energy for the medium-
low portion against the medium-high portion of the signal spectrum: when there is more energy in the me-
dium-low part (the “_e__o_” sections of the word “sector”) the circuit opens for the Carrier Voiced signal
produced by the oscillator; when there is more energy in the medium-high part (the "s_ct_r" sections of the
word "sector") the circuit opens for the Carrier Unvoiced signal produced by the Noise Generator.
The transition between the two Voiced/Unvoiced components is regulated, in older projects, according to
the manufacturer's preferences; in Grp V22, it is possible to apply different transition rules (see in the Refe-
rence Section) to have very fast, fast or not-so-fast transitions applied independently in the two directions V/
UV or UV/V.
Furthermore, in Grp V22, it is possible to work with the traditional alternation SWITCHED (the two V/UV
signals are alternated mechanically by the internal circuit - the result is pleasantly robotic) or in MIXED
mode, providing for the simultaneous and miserable presence of the two V/UV components (which guaran-
tees greater fluidity, intelligibility and naturalness to the final result).
Still, in Grp V22, it is possible to disable the Voiced/Unvoiced automated selection by choosing to always
work only with the vocal portion of the Carrier Voiced signal (full bodied sound results, but without the hi-
gher average components that ensure intelligibility) or only with the noise portion of the Carrier Unvoiced
signal (useful for playing whispered voices, ghost voices, wind telling ancient horror stories, etc.).
3.3.2 ADDING SPEECH HIGH PASS SIGNAL
Even if a fairly high number of Analysis / Synthesis bands guarantees a proper intelligibility of the signal
produced by the Vocoder (with a consequent increase in the final price of the unit, sadly), the quality of
what is produced by the Vocoder can be made much clearer by mixing carefully on the output a small por-
tion of the original Speech / Modulator signal limited with a strong High Pass filtering to only the very hi-
ghest part of the harmonic spectrum. On the control panel of the Grp V22, the LEVEL control of the HI
PASS section regulates the amount of highs originally present in the Speech / Modulator signal that will be
granted in the final output of the Vocoder.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4. FRONT PANEL - REFERENCE
Below, the description of the controls and connections on the front panel of the device. On the Vocoder
V22 control panel there are different categories of controls: activity LEDs, knobs to rotate (controls), swit-
ches to be activated (with two or three positions), selectors for choosing a behavior, inputs and outputs.
The description proceeds section by section.
4.1 MIDI SECTION
Contains commands for MIDI behavior.
4.1.1 ACT LED
The LED lights up every time the V22 receives a MIDI messages transmitted from other devices.
4.1.2 GLIDE Control
Adjusts the Glide Time applied to the pitch of the Internal Carrier oscillator; in fully clockwise position, the
maximum Glide Time corresponds to 2.5 sec/oct.
4.1.3 MIDI TO CV Switch
In the ON position, this switch enables the pitch control of the Internal Carrier oscillator by the MIDI Note
On/Off messages transmitted from other devices. When the switch is in the OFF position, the frequency of
the internal oscillator can only be controlled with the VCO TUNE panel command and/or from the control
voltage received at the VCO 1V/OCT input port.
The Switch and the ACT LED perform multiple functions.
4.1.3.1 Setting the Vooder receiving MIDI Channel
When the Vocoder is turned on, when the MIDI TO CV switch is in the ON position, the LED starts flashing
indicating that the unit is waiting to receive any MIDI message to set the Vocoder to the MIDI channel of
the message itself. With the MIDI channel assigned, the LED stops flashing, indicating that the interface is
working properly; from that moment on, the LED works as a MIDI Activity viewer.
If the MIDI TO CV switch is in the OFF position when the Vocoder is turned on, the MIDI interface is not
activated and the LED does not flash. The internal VCO in the INTERNAL CARRIER section receives a de-
fault voltage equal to + 3V which sets its base frequency (you can change the Carrier pitch with the front
panel knob or with an external analog CV). As soon as the switch is turned ON, the LED starts flashing to
indicate the standby status of any MIDI message useful for tuning the reception channel.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.1.3.2 Changing receiving MIDI channel without turning off the unit
If you want to change the MIDI channel without turning off the instrument, first set the MIDI TO CV switch
to the OFF position and then move it to ON; the LED starts flashing indicating the start of the previously
highlighted MIDI reception/tuning waiting procedure.
4.1.3.3 Driving Vocoder pitch with MIDI
If you want use analog CV for control the Vocoder pitch generated by the CARRIER INTERNAL analog oscil-
lator, set the MIDI TO CV switch to the OFF position.
4.2 SPEECH IN SECTION
It contains the COMBO connector for the external Speech/Modulator signal and controls to optimize its
performance. The Speech/Modulator signal is essential for the correct operation of the Vocoder.
4.2.1 MIC/LINE INPUT Connector
The combo connector accepts XLR microphone signals or 1/4 ”TS/TRS format line signals. The signal at this
connector is used as a Speech/Modulator by the Vocoder circuit.
4.2.2 COMP Control
Clockwise adjusts the intensity of the compression applied to the input signal.
4.2.3 NOISE GATE Control
Clockwise adjusts the effectiveness of the noise reduction applied to the input signal.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.3 PREAMPLIFIER SECTION
Display and adjust of the level for the microphone signal.
4.3.1 Vu-Meter MIC/LINE LEVEL
Displays the level of the Speech/Modulator signal received at the MIC / LINE input.
4.3.2 INPUT GAIN Control
Adjusts the level of the MIC/LINE input signal.
4.4 COUPLING SECTION
It manages the numerical correspondence between the analysis and synthesis bands.
4.4.1 ENV FOLL -> VCA Selector
It allows you to alter the coupling between analysis bands and synthesis bands. In the central position "0",
the 22 analysis bands control the 22 synthesis bands with direct numerical correspondence; in the positions
"+1, +2, +3", the analysis band controls the immediately following synthesis band (numerical offset equal
to +1), or the second (numerical offset equal to +2) or the third (numerical offset equal to +3) and so for all
the other 21 bands. In positions "-1, -2, -3" a negative offset is applied which allows the twenty-second ana-
lysis band to control the twenty-first synthesis (numeric offset -1) or the twentieth (numeric offset -2) or the
nineteenth (offset numeric -3). With numerical offsets other than “0”, synthesis bands in numerically ex-
treme position can remain uncontrolled.
Below, the reproduction of the possible couplings
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
Condition 0
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
SYNTHESIS
Condition +1
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 -
SYNTHESIS
Condition +2
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 - -
SYNTHESIS
Condition +3
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 - - -
SYNTHESIS
Condition -1
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
- 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21
SYNTHESIS
Condition -2
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
- - 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20
SYNTHESIS
Condition -3
ANALYSIS
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22
| | | | | | | | | | | | | | | | | | | | | |
- - - 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19
SYNTHESIS
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.5 SLEW SECTION
Adjusts the response speed of the Envelope Followers present in the Analysis section of the signal.
4.5.1 FREEZE Switch
In the ON position, it freezes the decay of the Envelope Followers, prolonging endlessly the reading of the
analysis signals. The parameter can be controlled from the outside using a control voltage applied to the
SLEW 0 / + 5V input.
The command responds to MIDI CC # 64.
4.5.2 LED
The LED lights up monitoring the activity/speed of the Time command.
4.5.3 TIME Control
Adjusts the response speed of the Envelope Followers in the Analysis section. With minimum TIME values,
the Vocoder responds quickly to variations in the Speech/Modulator signal; with higher TIME values, the
behavior becomes progressively more lethargic.
The command responds to MIDI CC # 01 Mod Wheel.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.6 VOICED/UNVOICED SECTION
It contains all the controls related to the generation of the Carrier signals inside the Vocoder (Voiced-Oscil-
lator, Unvoiced-Noise Generator), with the possibility of receiving external signals alternative to those pro-
duced internally and the customization of Voiced/Unvoiced operation variations.
4.6.1 INTERNAL CARRIER - VCO TUNE Control
Adjusts the pitch of the internal oscillator used as the Carrier signal. The range is +/- 2 octaves.
4.6.2 INTERNAL CARRIER - BEND AMOUNT Control
Adjusts the range of the MIDI Pitch Bend command applied to the frequency of the internal Carrier oscilla-
tor. The range is covers +/- 12 semitones.
4.6.3 INTERNAL CARRIER - WAVE Switch
It chooses the SQR (square) or SAW (sawtooth) waveform for the internal Carrier oscillator.
4.6.4 INTERNAL CARRIER - FM Control
Adjusts the intensity of the frequency modulation received by the LFO module and applied to the oscillator.
4.6.5 INTERNAL CARRIER - PWM Control
Adjusts the intensity of the modulation on the symmetry received by the LFO module and applied to the
oscillator.
4.6.6 INTERNAL CARRIER - VOICED LEVEL Control
Adjusts the output volume of the internal Carrier oscillator allowing the balance of the Voiced component
(the sound of the oscillator) against the Unvoice component (the sound of the Noise Generator).
4.6.7 INTERNAL CARRIER - UNVOICED LEVEL Control
Adjusts the output volume of the internal Noise Generator allowing the balance of the Unvoiced compo-
nent (the sound of the Noise Generator) against the Voiced component (the sound of the oscillator).
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.6.8 Selettore V/UV MODE Selector
This command sets how the Voiced and Unvoiced signals are combined before being sent to the Summary
section.
• VOICED. The Synthesis section only receives the Voiced signal produced by the Internal Carrier oscilla-
tor. This can make it more difficult to recognize the spoken signal.
• UNVOICED. The Synthesis section only receives the Unvoiced signal produced by the Noise Generator.
This mode is useful for recreating the classic whispered "ghost voices".
• MIXED. The Synthesis section receives the mixed sum of the two Voiced (Oscillator) and Unvoiced (Noi-
se Generator) signals previously adjusted with the two VOICED LEVEL and UNVOICED LEVEL com-
mands. This mode allows for a softer behavior and makes easy to understand of the spoken signal.
• SWITCHED. The Synthesis section receives the Voiced signal (Oscillator) when the vowels prevail in the
Speech/Modulator signal, it receives the Unvoiced signal (Noise Generator) when the consonants prevail
in the Speech / Modulator signal. The Switched transition is adjustable in speed and symmetry using the
two TIME and SYM switches (see below). This is the classic way of operating the old analog vocoders.
4.6.9 TIME Switch
The command is active only if the V/UV MODE selector is in one of the two positions SWITCHED and MI-
XED. The Switch choose the transition speed between Voiced and Unvoiced position between 10, 100 or
250 milliseconds.
4.6.10 SYM Switch
The command is active only if the V/UV MODE selector is in one of the two positions SWITCHED and MI-
XED. Adjusts the speed symmetry of the Voice-Unvoiced and Unvoiced-Voiced transition, ie the opening of
the selector that alternates the two Oscillator and Noise Generator signals towards the Analysis section.
•ATT/REL. The TIME value is applied in both opening and closing directions of the Voiced (Oscillator)/
Unvoiced (Noise Generator) selection.
•ATT. The TIME value is applied to the Voiced/Unvoiced transition only. The opposite Unvoiced/Voiced
transition remains set to 0 msec.
•REL. The TIME value is applied to the Unvoiced / Voiced pass only. The opposite Voiced / Unvoiced pass
remains set at 0 msec.
4.6.11 THRSH Command
The command is active only if the V/UV MODE selector is in one of the two positions SWITCHED and MI-
XED. Establishes the threshold beyond which the transition/selection of the Voiced and/or Unvoiced signal
is triggered.
4.6.12 VCA INIT GAIN Control
It allows you to keep the levels of the VCA sections in the the Synthesis bands constantly open. In this way,
the Vocoder can be used as a Fixed Filter Bank to influence/equalize the external signal connected at the
EXT.VOICED input instead of the Internal Carrier. In normal Vocoding operations, the control must be set to
zero, i.e. in the fully counter-clockwise position.
4.6.13 EXT VOICED Control
Adjusts the audio level of the external signal possibly connected to the VOICED port. It can be used as an
alternative to the Internal Carrier oscillator (for example, to obtain polyphonic behaviors in the Summary
section). With the control at maximum, x100 amplification is achieved.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.6.14 LED OVERLOAD
Lights up when the EXT VOICED signal exceeds the level allowed by the internal circuit.
4.6.15 EXT UNVOICED Control
Adjusts the audio level of the external signal possibly connected to the UNVOICED port. It can be used as
an alternative to the internal Noise Generator. With the control at maximum, x100 amplification is achieved.
4.6.16 LED OVERLOAD
Lights up when the EXT UNVOICED signal exceeds the level allowed by the internal circuit.
4.7 HI PASS SECTION
Improves the clarity of the signal produced by the Vocoder.
4.7.1 LEVEL Control
In the final mix, it adjusts the amount of signal coming from the High Pass filter applied to the Speech/Mo-
dulator signal connected at the MIC/LINE INPUT. In this way, it is traditionally possible to significantly im-
prove the intelligibility of the spoken signal produced by the Vocoder.
4.8 LFO SECTION
4.8.1 LED
The LED flashes, monitoring the speed of the waveform selected with the SQR/TRI switch.
4.8.2 SQR/TRI Switch
It allows you to choose the waveform generated by the Low Frequency Oscillator module. It is possible to
choose square (SQR) or triangular (TRI) wave. The modulation is applicable to the frequency of the Internal
Carrier Oscillator on both SAW and SQUARE waves through FM control and/or to the symmetry of the only
SQR wave of the Internal Carrier through PWM control.!
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.8.3 FREQUENCY Control
Adjust the speed of the low frequency oscillator. The range is from 0.02 Hz to 13 Hz.
4.9 MAIN OUT SECTION
Sets output level of the Vocoder.
4.9.1 Vu-Meter OUTPUT LEVEL
Shows the level of the signal output to the Vocoder.
4.9.2 Controllo MASTER VOLUME Control
Sets the output level of the Vocoder.
4.10 CONNECTIONS SECTION
Contains all the analog input and output connections for audio signals and controls.
4.10.1 INPUT - VCO 1/V OCT
It receives the control voltage to drive the pitch of the Internal Carrier Oscillator.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
4.10.2 INPUT - SLEW 0/+5V
It allows remote control of the SLEW response speed of the Envelope Followers present in the Analysis sec-
tion. By applying a voltage equal to + 5V, the Freeze condition is obtained.
4.10.3 INPUT - VOICED
Input port for the external audio signal to be used instead of the Internal Carrier Oscillator as a Voiced
component to be submitted to the Synthesis section.
4.10.4 INPUT - UNVOICED
Input port for the external audio signal to be used instead of the internal Noise Generator as an Unvoiced
component to be submitted to the Synthesis section.
4.10.5 OUTPUT - CARRIER
Output for the Internal Carrier signal taken post Voiced/Unvoiced selection; in this way, the same signal sent
to the Synthesis filter bank is made available for any external treatments.
4.10.6 OUTPUT - PHONES
Headphone output. Is under control of MASTER VOLUME knob.
4.10.7 OUTPUT - LEFT
Left Vocoder output. Contains the signals of only the odd number Synthesis bands.
4.10.8 OUTPUT - RIGTH/MONO
Right/Mono output of the Vocoder. If the two left and right outputs are connected, this port contains the
signals only of the Synthesis bands of even number; if used in Mono mode (connecting only the RIGTH/
MONO output and leaving the LEFT output disconnected), the port will contain the entire Vocoder signal.
The signals emitted by the Low Pass and High Pass filters (at the ends of the Sintesi filter battery) are simul-
taneously made available on both the Left and Right outputs.
4.11 SEZIONE MIXER (no label on front panel)
It allows you to adjust the output levels of the different synthesis bands and to arbitrarily alter the connec-
tion between the analysis and synthesis circuits.
4.11.1 LP 185 Hz, 220 Hz, 262 Hz, 311 Hz, 370 Hz, 440 Hz, 523 Hz, 622 Hz, 740 Hz, 880 Hz, 1047 Hz,
1245 Hz, 1480 Hz, 1760 Hz, 2093 Hz, 2489 Hz, 2960 Hz, 3520 Hz, 4186 Hz, 4978 Hz, 5920 Hz, HP
7040 Hz Controls
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
These adjust the output levels of the individual Synthesis bands. They allow to “re-equalize” the signal pro-
duced by the Vocoder. If the VCA INIT GAIN command is not at minimum value, it is possible to use the
Vocoder as Fixed Filter Bank on the signal present at the EXT.VOICED input.
4.11.2 LED LP 185 Hz, 220 Hz, 262 Hz, 311 Hz, 370 Hz, 440 Hz, 523 Hz, 622 Hz, 740 Hz, 880 Hz, 1047
Hz, 1245 Hz, 1480 Hz, 1760 Hz, 2093 Hz, 2489 Hz, 2960 Hz, 3520 Hz, 4186 Hz, 4978 Hz, 5920 Hz, HP
7040 Hz
They monitor the activity present in each of the 22 analysis bands.
4.12 ANALYSYS - ENVELOPE FOLLOWER OUTPUTS SECTION
Is the first row of connections under the signaling LEDs.
4.12.1 LP 185 Hz, 220 Hz, 262 Hz, 311 Hz, 370 Hz, 440 Hz, 523 Hz, 622 Hz, 740 Hz, 880 Hz, 1047 Hz,
1245 Hz, 1480 Hz, 1760 Hz, 2093 Hz, 2489 Hz, 2960 Hz, 3520 Hz, 4186 Hz, 4978 Hz, 5920 Hz, HP
7040 Output Connectors
Outputs the control signal processed by the 22 Envelope Followers present in the Analysis section and pro-
portional to the energy extracted in each band. The control voltages are internally normalized to the under-
lying SYNTESIS - VOLTAGE CONTROLLED AMPLIFIER INPUTS inputs, but they can be extracted with patch
cords and connected to external analog circuits for their control.
Each control voltage operates with an excursion equal to 0 / + 5V.
4.13 SYNTESIS - VOLTAGE CONTROLLED AMPLIFIER INPUTS SECTION
Is the second row of connections in columns under the signaling LEDs
4.13.1 LP 185 Hz, 220 Hz, 262 Hz, 311 Hz, 370 Hz, 440 Hz, 523 Hz, 622 Hz, 740 Hz, 880 Hz, 1047 Hz,
1245 Hz, 1480 Hz, 1760 Hz, 2093 Hz, 2489 Hz, 2960 Hz, 3520 Hz, 4186 Hz, 4978 Hz, 5920 Hz, HP
7040 Hz Input Connectors
They receive the control voltages to manage the levels of the 22 VCA in the Summary section. The inputs
are internally normalized to the ANALYSIS - ENVELOPE FOLLOWER OUTPUTS outputs above, but can be
patched for receive any control signals from an external analog source.
Each input can receive a control voltage with an excursion equal to 0 / + 5V.
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Grp Synthesizer V22 Analog Vocoder Rev 1.3
5. REAR PANEL
The Vocoder is housed in a cabinet with standard wooden side panels, but which can be installed in 19”
Rack using the special metal fins supplied. The cabinet, which is used to house both the Grp A2 Analog
Synthesizer and the Grp R24 Sequencer, has a double labeling showing the possible uses of the two DIN
connectors of the MIDI port:
• If the cabinet houses the Vocoder V22, the two DIN connectors work as MIDI In and MIDI Thru.
• If the cabinet houses the A2 synthesizer, the two DIN connectors work as MIDI In and MIDI Thru.
• If the cabinet houses the R24 Sequencer, the two DIN connectors work as MIDI In and MIDI Out.
The Vocoder V22, due to its analogue nature, does not transmit any MIDI data and does not need a MIDI
Out connector.
5.1 MIDI IN DIN Connector
Receives MIDI data sent from external devices. To change the Vocoder's MIDI receive channel, refer to the
procedures described at 4.1.3.1 and 4.1.3.2.
5.2 MIDI OUT/THRU DIN Connector
The connector operates in THRU mode and supplies a copy of the received data to the MIDI IN jack descri-
bed above.
5.3 USB HOST Connector
The USB HOST connector handles the received MIDI data and interprets the same codes as the MIDI DIN
serial port.
5.4 DC 24V-1.66A Connector
Use this connector to connect only the power supply supplied with the Vocoder.
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