New GRP A10 Flagship Synthesizer Incoming

These in via John L Rice.

Left: front panel layout.

Below: PDF with full details. Click on each pic to zoom in.





Introducing Grp Synthesizer A10

The Grp Synthesizer A10 is a great synthesizer (in every sense) that fully embodies the Grp philosophy: uncompromising construction, immediate access to the generation and control functions, integration of the synthesis structure with the performance control offered by the Step Sequencer (which takes up and expands the noble legacy of the powerful Grp R24 Step Sequencer) and the powerful MIDI Arpeggiator.

In addition, the A10 hosts a complete and flexible Analog Effects section (Wavefolder, Dual Triple Resonator Filter, 1-Sec BBD Stereo Delay, Dual Phaser, Stereo Spring Reverb) that enriches the signal produced by the instrument or any audio received from outside.

A generous array of audio and control in/out connections complete the features of this ultimate analog synthesizer.

Key Points

Philosophy

The instrument embodies the Grp DNA: uncompromising construction, hands-on access to all functions, minimal - but functional - implementation of parameters on the Display for the main configurations.

Organization

The synthesis resources of the Grp Synthesizer A10 can be organized to produce a single - massive - voice with four VCOs, four VCFs, two VCAs, two Waveshapers, two Triple Resonator Filters, a Dual Phaser, a 1Sec BBD Stereo Delay, a Stereo Spring Reverb, four EGs, three LFOs, an S/H, a RingMod, an Env Follower under control of the Step Sequencer (Mono or Dual Mode) or can be distributed in two independent operational timbre sections Upper and Lower (Split Mode) freely controllable by MIDI/CV keyboard or Step Sequencer or Arpeggiator.

Completeness

A Production/Performance Electronic Music Studio in-a-box: add a Master Keyboard (or a MIDI Track) and an amplification system and you've done.

Powerful Sound Sources

Thenew Grp oscillators make available classic analog waveforms (including the famous Grp Sine Wave - arguably the purest commercially available sine wave in an analog oscillator) plus SuperWave customization applicable to Super-Sine, Super-Triangle, Super-Saw, Super- Square. The result is devastating.

You Have: VCO 1, VCO2, VCO3, VCO4, SUBVCO 1, RINGMOD 3*4 (or EXT*4), NOISE, EXT IN/FBK.

Flexible and complete audio path

Each sound source can be continuously rotated to the first or second VCF. The two VCFs in turn can work in Parallel, Serial 1-2 or Serial 2-1 mode.

The filter signal is received by a pair of VCAs equipped with a dedicated envelope and dedicated AM function. The output of the two VCAs is finally regulated through the MAIN MIXER - AUTO PAN section, with level visualization through a pair of Vu-Meters and manual or automatic adjustment on the stereo vectorization of the signal.

External Input & Envelope Follower Grp

Synthesizer A10 can receive an external audio signal, adjust its audio level for subsequent processing and process the Gate Extraction controls (with adjustable Gate Threshold) from the audio signal to trigger the internal Envelopes and Envelope Follower (to control the operation of the synthesizer based on the intensity of the external signal).

Many Filters

The Voltage Controlled Filter 1 can work in -12dB Vactrol or -24 dB Transistor Ladder configuration (with selection of the desired order: from LP1 to LP4 with or without Gain Compensation).

The Voltage Controlled Filter 2 can work in -18dB Diode Ladder or -12 dB State Variable Filter configuration (with HP2, BP1, LP2, BR1, BR2 selection). In all configurations, it is possible to modulate the amount of Resonance. Each filter has independent Envelope Amount with positive or negative polarity.

Audio Processing Grp

Synthesizer A10 opens, for Grp, the integration of analog effects within the synthesis channel.

The instrument is equipped with: Dual Voltage Controlled Wavefolder (adjustable in Pre/Post Filter position, with modulatable Wavefolding Amount); 1-Sec BB Stereo Delay (synchronizable independently on the two channels, with Tap Tempo and Time Modulation, Clock Divider, PingPong switchable, also usable for external signals), Dual Triple Resonator Filter (each with built-in LFO, three adjustable Resonant Freq, Resonance High/Low, Dry/Wet), VC Dual Phaser (each section configurable 6/12 Stages, with Phase Reversal), Spring Stereo Reverb (two independent tanks, to preserve the stereo flow, with adjustable Reverb Return).

External and internal controls

In addition to MIDI/USB signals (the 16-bit DAC converts Note On/Off, Key Velocity, Pitch Bend, Channel

Aftertouch, ModWheel, Sustain, Volume, MIDI Clock) and CV/Gate signals received from outside, Grp

Synthesizer A10 offers: two Voltage Controlled Envelope Generator 1 and 2 in Delay-Attack- configuration Hold-Decay-Sustain Level/Time-Release (with selective Loop activation, with or without Keyboard-AND, independent Wheel/Vel/Seq modulation on Attack-Decay-Release Time, activation from MIDI/USB keyboard/ CV, Step Sequencer, S/H Clock/External In and two simultaneous CV outputs with independently adjustable Amount and Polarity), two Voltage Controlled LFO 1 and 2 (with adjustable Frequency and controllable from internal and/or external CV sources to the instrument, selectable Waveform, with Shaping on the external signal; it is possible to synchronize the modulation cycle to the Step Sequencer and to other Clock sources); a Performance Low Frequency Oscillator (with adjustable Frequency, Range, Shape and Shaping, addressable to VCO1-2, VCO 3-4, PWM1-2, PWM3-4,VCF1, VCF2, VCA1, VCA2).

Assignable Modulations Grp

Synthesizer A10 expands the semi-modular Grp philosophy based on high-quality mechanical multiselectors to offer maximum flexibility of use without having to resort to physical patching. The four VCOs, the two VCF blocks and the two ASSIGN blocks each offer access to 21 possible Audio/Sub Audio modulation sources freely assignable to the pivot points of the instrument (Osc Frequency, Filter Cutoff, Assignable Source). In addition, the CV signals selected in the ASSIGNABLE CV 1 and CV 2 sections can be routed to VCO1-4 FM2, VCO1-4 PWM, WAVEFOLDER 1-2 Amount, VCF1-2 Resonance, Triple Resonator Filter 1-2 Mod Frequency Amt, VC Dual Phaser Mod Rate Amt, Mod Feedback Amt, VCA1-2 Mod AM Amt.

MIDI Arpeggiator A

powerful MIDI Arpeggiator addressable to the Upper or Lower parts (when the instrument is in Split mode) or to the entire instrument, with adjustable Pulse Width configurable in Advance Mode, Note Repeats, Octave Range and Advance Division (to de-align the Arpeggiator rhythm from that of the Step Sequencer).

Step Sequencer 8*3

Imagine a Grp R24 inside the synthesizer: now, imagine it more powerful, simpler in the immediate choice of important parameters, with the capability of storing sequences of notes up to 24 Steps long. Three rows of 8 Steps each, which can be organized in 8*3, 16+8, 24 Step configurations. Each Step, in addition to adjusting its own value (of pitch or CV control), can trigger the synthesizer's Envelopes

(each Envelope can be connected to the desired Sequencer Row ABC independently from the others), or enable Portamento or Activate Ratchet bounces or more. Each row can work independently as Order, Step Repeat, Advance Rate Division, Row Advance, Function Activation. The Sequencer can be clocked internally, via MIDI/USB, via Analog Sync TTL, via keyboard.

The stored sequences are stored and can be recalled at the user's discretion at any time. moment.

A dedicated Clock center

Grp Synthesizer A10 is equipped with a Clock center that can be customized to differentiate - simultaneously - the advance density of the Arpeggiator and the Step Sequencer. But it can also be used to manage the modulation cycles of the VC LFO 1 and 2, the analog Stereo Delay, the Sample & Hold.

All the connections of the world

GrpSynthesizer A10 offers a block of 57 + 2 front Audio and CV/Gate control connections unbalanced and balanced XLR through which to interface the instrument with the outside world.

You can connect the balanced Main L/R outputs, or take the Upper and Lower L/R stereo pairs, manage headphone listening or receive external monaural signals.

The Analog Delay, Reverb and Phaser sections can be used completely independently to process external stereo signals; all the most important parameters can be managed via CV/Gate.

The Step Sequencer offers a full complement of connections for CV/Gate control of independent external analog devices (one for each Row ABC) and can in turn be externally analog driven for Run/Stop, Reset, Loop On/Off behaviors.

Complete Feature List

CONFIGURATION & MASTER

• Configuration. The Grp Synthesizer A10 offers three configuration modes for controlling the structure internal:

• Mono: Single MIDI Channel that manages all internal resources. The user can however differentiate the timbre behavior in two possible Upper and Lower sections that will perform the same note with two different sounds.

• Dual: Dnico MIDI Channel that manages two notes simultaneously. The user can standardize the timbre structure on a single behavior or experiment with the timbre tracking between the two possible Upper and Lower sections that differentiate the timbre adjustments of the internal resources.

• Split: Two independent MIDI Channels; each channel controls the Upper or Lower section, with the maximum independence in articulation and timbre control.

• MIDI Interface Din-5 and USB: A MIDI Din-5/USB interface that handles the following incoming messages:

• Note On/Off with 16- bit DAC.

• Velocity Notes.

• Pitch Bend Wheel.

• Modulation Wheel.

• Channel Aftertouch.

• Sustain Pedal #64. • Volume.

• MIDI Clock & Realtime Messages.

• Master & Display

• Direct access to the various Parameter Menus (MIDI Ch, Priority, Mode, Retrig, 440Hz, Manual Gate Upper/Lower).

• Master Clock:

• Clock In selection (Internal, EXT TTL, MIDI).

• Clock Out selection (Master, Seq, Arp).

• Time Division can be activated independently and simultaneously (with different coefficients) for: Seq, Arp, S&H, VCLFO1, VCLFO2.

SYNTHESIZER

• Oscillator Section

• 4 VCOs with six waveforms: Saw, Square, Square+Saw, Triangle, Triangle+Saw, Sine. • The Sine wave is available both in the filter path and directly at the input of the modules VCA.

• Octave switch from 64' to 2’.

• Tune and Fine control.

• Hard Sync .

• Cross Modulation between the 4 VCOs.

• Gate Reset on the waveform (to facilitate consistent behaviors in the production of timbres percussive)..

• Two separate Super Saws for the two Upper/Lower sections (VCO 2 and VCO 4).

• Two FM LIN/EXP Modulation sends. FM1 with 21-position switching (to choose between as many modulation sources) and phase control of the modulation.

• PW and PWM controls.

• Ring Modulator between VCOs 3 and 4.

• Mixer

• Independent volumes for the 8 sources.

• Routing control for continuous source routing to VCF1 and/or VCF2.

• Filter Section

• 4 filter types:

• VCF Transistor ladder 24db Low Pass with Frequency and Resonance control.

• Switching slopes 6, 12, 18, 24dB.

• VCF State Variable Filter 12db with Frequency and Resonance control with the following modes:

• -12 dB/Oct HP: Two-pole high pass.

• -6 dB/Oct BP: Single-pole band pass. • -12 dB/Oct LP: Two-pole low pass.

• -6 dB/Oct NOTCH: Single-pole band reject.

• VCF 18dB Low Pass Diode Ladder.

• VCF 12dB Low Pass Vactrol Technology.

• All VCFs feature CV Resonance, two modulation sends and distortion.

• Both VCFs can be rotated in Filter Pan mode.

• VCF1 in series with VCF2 and VCF2 in series with VCF1.

• Wavefolder Section

• Fold, Feedback and AMT CV controls. Routing between Pre or Post VCF.

• VC Envelope Generators

• 2 VC Envelope Generators for VCF Section with controls for: Delay, Attack, Hold, Decay, Sustain Level, Sustain Time and Release.

• Independent EG Amount for the two VCFs.

• Attack, Decay and release under CV control of Velocity, Mod W, Sequencer, LFO.

• Normal, Loop Auto and Loop modes under Keyboard Gate AND control.

• Attack, Decay and release under CV control of Velocity, Mod W, Sequencer, LFO.

• AM Amount.

• Triple Resonator Filter

• Two Triple Resonant Filters with three frequency control, Dry/Wet and Master Frequency.

Dual Phaser Dual Phaser for the two audio sections

• Sweep, Feedback, Modulation AMT and Rate control.

• Switch for selecting 6 or 12 stages.

• Bypass switch.

• VC Amplifier 1/2 - EG 2/4

• Amplifier Envelope Generator 2/4 with Attack, Decay, Sustain, Release controls.

• Gate source selection:

• Kybd/SH or Sequencer Row ABC.

• Loop: Gated, Auto, Off.

• CV VCA Select:

• EG2/4, External CV, HOLD.

• Amplitude Modulation:

• AM Amount.

• AM Mod Source Select:

Assign 1/2, LFO 1/2.

Direct Sine Wave (Pre Filter) Level: VCO1, VCO2, VCO 3, VCO4.

• Main Mixer & Auto Pan

• Volume and Pan controls for the two synthesis channels.

• Independent auto Pan insertion for the two sections.

• Stereo Main

• Master Volume Control

• Twobacklit mechanical Vu-Meters (-20/+3dB).

• LFOs

• Two VCLFOs with 5 waveforms:

• Sine, Saw, Triangle Rev Saw, Square.

• Synchronization via gate, Master Clock and sequencer.

• 11-position Shaping Select.

• One LFO with two independent VCAs for the two sections, waveform adjustment via control SHAPE.

• 8 modulation sends to the main modules.

• Sample & Hold

• 11-position switch for selecting the input signal.

• Switch for switching the trigger between internal, LFO and Master Clock.

• Quantization in semitones of the output CV.

• Clock EG in Auto or under Gate control.

• Assignable 1 and 2

• Two 21-Position Switches for CV Source Routing. Control sources include: • LFO1-2, VCO1-4, SINE 1-4, RM, SUPER SAW, SEQ ROW ABC, S&H, NOISE, EG3-4, Aftertouch, ModWheel, EXT CV1-2.

• The modulation produced by each Assignable section is controlled in SHAPING with: Aftertouch, ModWheel or Hold Condition.

ARPEGGIATOR & STEP SEQUENCER

• Arpeggiator

• Assignable to the Upper or Lower section (if the instrument is set to Split Mode).

• Customizable:

• Advance Mode (Up, Down, UD, Pendulum, Random).

• Note Repeat (X2, X3, X4, X5, X8).

• Octave (X2, X3, X4, X1-, X2-).

• Advance Rate Division (/2, /3, /4, /1.3, /1.5).

• Adjustable Gate %.

Step Sequencer

• Configurable in 8*3 mode (three independent RowA-BC for length that run in parallel), 16+8 (two Row

AB up to 16 Steps and the third Row C up to 8 Steps that runs in parallel), 24* (a single sequence with Rows A+B+B configurable up to a maximum of 24 Steps in length).

• Each Row is independently configurable in Step Sorting Order (1.3, 1.2.1, 1.3.5, 1.1.21, 1.2.3.2), Step Repeat (X2, *2, Ratchet *3, Ratchet *4, Glide On/Off, Legato On/Off).

• Each Row is independently configurable in: Portamento Time, CV Range (X2, X4, X5 Volts), S&H On/Off, Quantizer On/Off.

• Each Step is adjustable in: Value, Gate Activation (Gate1/Off/Gate2), Function Activation (Off, Fnc1, Fnc2), Mode (Normal/Skip/End Step).

• Independent Row Lock ABC.

• Master Advance Mode for fast configuration FW, BW, FW/BW, PNDL, ALT, RND.

• Adjustable Gate %.

• Memory Read for Sequence Recall, Memory Write for Sequencer Save, Panel Mode for direct behavior.

• Row C Assign addressable to: Row Advance Mode, Row Transpose, Row Order, Step Repeat #, Advance Independently addressable divisions for Row A and B.

• Manual Step Advance for programming.

• Run/Stop can be activated remotely.

• Loop On/Off and

Reset can be activated locally or remotely.

• Complete MIDI implementation.

CONNECTIONS

• Step Sequencer Connections

• Row A+B+C: Gate 1 Out (0/+5V), Gate 2 Out (0/+5V), CV Out (0-+5V), Transpose CV In (0/+5V).

• Row B: as above, independent from the other Rows.

• Row C: as above, independent from the other Rows.

• Remote Control: Run/Stop, Reset, Loop On/Off (+5V Mom Switch).

• Analog Delay Connections

• Audio In L/R.

• Audio Ou L/R.

• CV Time In L/R.

• CV Feedback In L/R.

• Tap Tempo Mom Switch: Left, L/Right.

• Reverb & Phaser connections

• Reverb In: L/R.

• Reverb Out L/R.

• Phaser In: L/R.

• Phaser Out: L/R.

• CV Input

• VCF 1 Cutoff.

• VCF 2 Cutoff.

• VCA 1 Amplitude.

• VCA 2 Amplitude.

• VCLFO1 Freq.

• VCLFO2Freq.

• Keyboard & MIDI Din-5/USB Interface

• Keyboard Lower Gate In (0/+5V), CV In(1V/Oct).

• Keyboard L/Upper Gate In (0/+5V), CV In(1V/Oct).

• Clock (TTL 0/+5V)

• Clock In. • Main Clock Out.

• Seq Clock Out.

• Arp Clock Out.

Audio

• Pre Master Out Upper Left - Right. • Pre Master Out Lower Left - Right.

• Post Master Out Left - Right.

• External In.

• Phones Out L/Right

• Balanced XLR Main Out Left - Right.

• Dimensions

• 1200mm x 560mm