A1 Desktop Semi-Modular Analog Synthesizer

Grp A1

Grp’s A1 is their most compact analog synthesizer to date, delivering their renowned quality and sound in a desktop, semi-modular package. Containing everything you need to create satisfying sounds, A1 is a complete subtractive synthesis instrument. For convenience, Grp even included an internal MIDI-CV interface, allowing you to use your favorite MIDI controller or sequencer to play the A1.

At its core is a true analog VCO, with selectable triangle, sawtooth, and square waveforms, plus a sub-oscillator. These, plus the white noise generator, are summed together before running into the 18dB/Oct lowpass filter, which may be optionally modulated by one of two LFOs as well as the ADSR envelope generator. Crank the resonance for intense sweeps or self-oscillation, or dial in Distortion for some grit. An output VCA provides another stage of amplitude shaping before heading to the main and headphone outputs.

As a semi-modular synthesizer, you don’t need to patch up the A1 to get great sounds out of it. But while it features a pre-configured signal path, the patch points along the bottom allow for customization depending on the musical scenario, whether it’s from alternative signals from the A1 itself or other instruments in your collection. Patch one of the LFOs into the VCA CV input for tremolo effects, or try patching the VCO output into the VCF CV input for some airy timbres. Regardless of how you patch or play, Grp’s A1 is a dependable synth with a great take on a classic sound.

A1 Features

• Analog semi-modular synthesizer
• Fully-analog signal path
• Onboard MIDI-CV converter with Glide and Pitch Bend controls
• Analog VCO with triangle, sawtooth, and square waveforms
• Sub-oscillator and noise generator
• 18dB/oct lowpass filter with resonance, distortion, and note tracking
• Two LFOs with shapable triangle/sawtooth and pulse waveforms
• Sample and hold on LFO 1
• ADSR envelope generator may be routed to VCO pitch, VCF cutoff, and VCA CV input
• Six patch point intputs, including external 1V/Oct, Gate, and External audio input
• Main and headphones output
• MIDI DIN input on the rear
• USB-C powered