Grp Synthesizer A4

• Three oscillators with six waveforms each, exponential and linear FM, hard sync and sub oscillator (Osc 1 and 2)
• Ring modulator, Noise with White and Pink Noise. Sample and Hold
• External Input with Envelope Follower
• Audio Mixer for Oscillator 1-3, Sub Oscillator, Noise, Ringmodulator and External Input.
• Filter Section: Dual filters each with Overdrive: Multimode SVF and LPF with variable edge steepness.
• Stereo output with Auto Pan function2 envelope generators AHDSR or ADSR with loop function
• Two envelope generators AHDSR or ADSR with loop function
• Two LFOs from very slow up to 2.5Khz and with various waveforms
• Sophisticated analog sequencer that can also be found in the A8. With 2*8 or 1*16 steps total length, different playback modes, ratcheting and clock divider.
• Extensive MIDI implementation

Grp Synthesizer A4

Sintetizzatore analogico con un'architettura di sintesi incredibilmente profonda e potente

Il Grp Synthesizer A4 è stato sviluppato per offrire agli amanti del suono analogico uno strumento più accessibile rispetto al precedente modello A8, in termini di costi e dimensioni, senza rinunciare alla qualità e alle prestazioni che caratterizzano i nostri sintetizzatori. Equipaggiato con lo stesso step sequencer del Grp A8, lo strumento è in grato di fornire combinazioni sonore pressochè infinite, grazie alle nuove caratteristiche implementate nello strumento, con la possibilità di filtrare segnali esterni e di gestire tutti i parametri più significativi nella catena di generazione analogica. Derivato da una sezione audio del grande Grp Synthesizer A8 (del quale riprende la struttura), l’A4 risulta più versatile ed eclettico passando da sonorità morbide ed estremamente pulite a suoni più duri grazie ai due distorsori installati nello strumento (uno per ciascun filtro) e alla possibilità di far interagire sintetizzatore, ring modulator, segnali esterni e step sequencer in un unico meccanismo di enorme potenza timbrica. Inoltre, la funzione Loop EG permette la ripetizione condizionata o incondizionata delle traiettorie d'inviluppo, per raggiungere sonorità timbriche particolari ed articolate nel tempo.

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Specifiche Tecniche

Voltage Controlled Oscillator 1, 2, 3

Wide audio range (64’-2’) w. Tune & Fine; six analog waveforms (sine, triangle, triangle & saw, saw, saw & variable pulse summed, variable pulse); manual pw & pwm (from VCLFO1, EG1, S&H, Aft); FM 1 Amt (lin/exp –from VCLFO1, LFO2, VCO1, 2, 3, Noise, S&H, EG1, EG2, Aft, ModW, KeyVel, EnvFoll) w. phase rev; FM 2 Amt (only exp – from VCLFO1, Env Foll); sub oscillator (on VCO 1, 2) -1/-2 oct; hard sync (VCO 1 master); kybd on/off (w. user’s selectable octave offset from MIDI Interface).

Ring Modulator

Ring Mod Sources: VCO 2 & VCO 3/Ext Input (user’s selectable).

Noise Generator

White & Pink Noise selectable.

External Input

Input gain from line to mic level; freely adjustable Gate Threshold (Gate to EG 1-2); enclosed envelope follower (goes into mod buss).

Audio Mixer

Separate level controls for VCO 1, 2, 3, Sub 1, 2, Ext Input, Ring Mod, Noise.

Filter Section

Dual analog filter section: 24 db/Oct Low Pass Transistor Ladder Filter w. pole selection & 12 dB/Oct State Variable Low, Band, High, Notch Filter. Each filter has a separate Distortion/Level control. Filter section can be configured in LP 24 Only, SV 12Only, Serial (LP into SV), Parallel, Direct Out (LP 24 goes on Left Audio Out, SV 12 goes on Right Audio Out). Low Pass Filter: Slope selection (6, 12, 18, 24 dB); Cutoff Frequency; Resonance; Overload LED; FM1 Amt (from VCLFO1, LFO2, VCO 1, 2, 3 Env Foll, Noise, S&H, EG2, Aft, ModW, KeyVel) w, phase rev.; FM 2 Amt (from VCLFO 1); FM 3 Amt (from Step Sequencer, Kybd Track 0-120%; Key Vel On/Off. State Variable Filter: Mode (12dB HP, 6 dB BP, 12 dB LP, 6 dB Notch); Cutoff Frequency; Resonance; Overload LED; FM1 Amt (from VCLFO1, LFO2, VCO 1, 2, 3 Env Foll, Noise, S&H, EG2, Aft, ModW, KeyVel) w, phase rev.; FM 2 Amt (from VCLFO 1); FM 3 Amt (from Step Sequencer, Kybd Track 0-120%; Key Vel On/Off.

Voltage Controlled Amplifier

Dedicaded Envelope Generator (see below); Control Selection (dedicated EG2, ON-hold, External CV); VCLFO1 Amt.

AutoPan

AutoPan Off/Internal Clock/VCLFO1; Pan Frequency Control; LED (red = internal clock; blue = VCLFO1).

Stereo Main

Master Volume.

Envelope Generator 1

Multi Stage Loopable Env (Attack, Hold, Decay, Sustain Lev, Sustain Time-Only in Loop On, Release); Gate Source Selection (Keyboard, S&H, ExtIn/ Step Seq); independent EG Amt for 24 dB LP Filter and 12 dB State Variable Filter, both w. user’s selectable EG polarity. EG time goes from 1msec to 20 sec. LED: red = EG under Gate sources; blue = EG under Step Sequencer control; Loop Envelope: loop from Attack to Release, w. Sustain Time selectable. Loop Mode Switch: Loop Off: EG as standard AHDSR, no Sustain Time. Gate: EG loops from A to S (w. Sustain Time max 60”) as long as Gate is On. Auto: EG full loop, from A to R; independent from Gate.

Envelope Generator 2

Same as EG 1, without Hold segment. Voltage Controlled Low Frequency 1 Frequency (from very low to 2500 Hz); Waveform (sine, ramp, triangle, saw, square w. variable pulse); FM Amt (exp, w. phase normal/rev); FM Sources (Key, EG1, EG2, LFO2, Seq A, B, A+B, S&H, Aft, ModW, EnvFoll); Sync (Off, Gate, Seq, MIDI – dividing factor selectable from internal MIDI Interface); Shaping LFO out (from: Off, EG1, EG2, Lfo2, SeqA, B, A+B, S&H, Aft, ModW, EnvFoll). LFO act as modulation buss for auxiliary sources: EG1, EG2, S&H, Noise, VCO2, EnvFoll. The aux source can be amplitude modulated with the Shaping Select.

Voltage Controlled Low Frequency 2

Frequency; Freq Range (Low-Mid-High); Waveform (Triangle, Square); Shaping Select (Off, Aft, ModW). Independent Send Modulations for: VCO 1, 2, 3 freq; PWM 1, 2, 3; VCF 24/12 Cutoff; VCA Level.

Sample & Hold

Frequency; Frequency Source (Int, VCLFO1); LED (red = Internal, blue = VCLFO1); S&H Source (Pink Noise, White Noise, VCLFO 1, LFO 2, VCO 1, 2, 3); Glide. The S&H Clock can be routed to EG firing; there are three options: Off – no routing; Gate – the S&H clock is ANDed with keyb/ext/manual Gate; Auto – EGs always fired from S&H.

Tuning/MIDI

Master Tune; Portamento Time; Bend Amount; VCO 1 Portamento On/Off, VCO 1, Bend On/Off; Hold On/Off; A440 On/Off; Retrig On/Off; Manual Gate. MIDI Interface: MIDI Channel Select; Keyboard Off Octave Offset; External CV In Octave Offset; MIDI Clock Divider on LFO Reset. A4 receives: MIDI Note On/Off, Bend, Modulation, Aftertouch, Key Velocity, Expression Pedal, Damper.

Step Sequencer

User’s configurable Mode Select 8x2 or 16x1. Clock Source: Int, VCLFO1, Ext, MIDI. Clock Divider on all Clock Sources; dividing factor MIDI: 1/1, ¼, 1/4t, 1/8, 1/8t, 1/16; dividing factor TTL: 1/1, /2, /4, /16, /32. Sequencer Mode: FW, BW, FW/BW, PNDL, ALT, RND, TRG. CV Seq Clock: A, Off, B on internal Clock. VCO Seq Enable: VCO 1, 2, 3, Off/A/B/A+B VCF Seq Enable: 24dB Off/A/B/A+B; 12dB Off/A/B/A+B. Step Repeat: Off, x2, x3, x4. Permutations: n,n+1; n, n+1, n; n, n, n+1, n. Loop On/Off. Hold On/Off. Manual Controls: Reset/Step Advance, Run/Stop, Continue Pulse Width (legato/staccato) on Internal & MIDI Clock. Row A & B Parameters: Glide Amt; Range (x2, x4, x8); Quantizer On/Off. Step Parameters: LED; Step Value; Gate On/Off; Step Mode (End, Skip, Normal).

Connections

Audio: Mono Out; Phones Out; Left/24dB Out; Right/12 dB Out; Audio External In. Filter: CV In 24 dB; CV In 12 dB. Amplifer: CV In VCA/After Touch Synth Control: CV In; Gate In. Sequencer Connections: Row A/B/A+B CV Out; Row A/B/A+B Gate Out; Run/Stop In; Continue In; Loop On/Off In; Clock Input; Clock Output; CV In Clock Modulation. Dimensions: 815mm x 455mm x 252mm Weight: 20 Kg ca