A4 Analog Synthesizer

Grp Synthesizer A4

The Grp Synthesizer A4 is a direct descendent of the flagship A8, providing the same analog sonic power and flexibility at a fraction the price. Ideal for everything from smooth Minimoog-like leads to distorted, tearing bassline sequences, the A4 is equipped and ready. Its three oscillators with various modulation and sync options, dual filters with integrated distortion, powerful modulation sources, and integrated 8×2 sequencer make it perfect for everything from classic monosynth sounds to intricate polyphonic sequenced or generative soundscapes. Eschewing patch cables or modulation matrices, the A4 instead relies on switches and knobs for signal routing and attenuation, making it quick and easy to reach new (and even unexpected!) sounds while keeping the user interface uncluttered and accessible. Round this all out with inherent MIDI support, external CV/Gate access, external audio input, and a beautiful wood cabinet with rock-solid construction, and it becomes apparent that the A4 is not just a cool synth for the moment: it is a destined classic.

A4 Features

• Three VCOs with vast modulation, sync, and tuning options
• Dedicated Ring Modulator for internal and external signals
• Noise generator switchable between White and Pink
• External input with plenty of gain for line and mic-level signals
• Dedicated envelope follower and comparator for External Input
• Audio mixer with level controls for all sources
• Dual analog filters: one 24dB/oct Transistor Ladder LPF with pole selection, one 12dB/oct state-variable filter
• LPF offers multiple slope choices and three FM inputs, and distortion
• SVF offers mode selection, three FM inputs, and distortion
• VCA with dedicated envelope generator and control selection
• Autopan section with controllable panning rate
• One looping AHDSR-style envelope with selectable gate source, pre-routed to sensible destinations
• Second envelope with all the features of the first, barring the Hold segment
• Two voltage-controllable LFOs with a variety of waveforms and destinations
• Sample & Hold with internal and external clock options and selectable sample input sources
• Master tuning controls
• Built-in MIDI interface accommodates note messages, pitch bend, modulation CC, aftertouch velocity, and more
• Built-in Step Sequencer with 8×2 and 16×1 modes, multiple directions, built-in clock divider, step repeat, permutations, and more