Grp Synthesizer A10: Is it the “Ultimate Analog Synthesizer?”
No compromises detected.
4,1 / 5,0 | 
Grp Synthesizer A10 is the company’s new flagship analog synth with four VCOs and VCFs, a step sequencer and analog effects.
Grp Synthesizer A10
Often, synthesizers are an exercise in compromise. Manufacturers and their engineers would like to design instruments that are full to bursting with parameters and functionality, but there’s always the issue of cost. First, you set the target price, and then you design the instrument to meet that goal.
The Italian boutique analog synthesizer outfit Grp Synthesizer this weekend announced its new flagship instrument, A10, and judging by the spec sheet included in the email blast, they have decided to go the other way and put in just about everything possible, from a plethora of synthesis parameters to a sequencer and – a first for the company – a clutch of analog effects. How expensive will it be? That remains to be seen.
Grp Synthesizer A10: The “Ultimate Analog Synthesizer”
Grp is calling its upcoming instrument the “ultimate analog synthesizer.” That’s quite a claim – but in this case, the Grp Synthesizer A10 may be just that. Along with all of the sound synthesis parameters (more later), you can configure it in two different ways: as a single, massive voice or as two separate sound sources controllable via keyboard split or the onboard step sequencer or arpeggiator.
Grp Synthesizer A10: VCOs and VCFs
The Grp Synthesizer A10 is equipped with four VCOs, each with a selection of classic waveforms that you can transform with the SuperWave function, giving you Super-Sine, Super-Triangle, Super-Saw and Super-Square shapes. It also offers PWM as well as hard sync, cross modulation and FM. There’s also a sub-oscillator, ring modulation between oscillators three and four (or an external source), and noise.
There are two filter sections in the Grp Synthesizer A10 with three separate signal paths available: Parallel, Serial 1-2 or Serial 2-1 modes. Additionally, each filter has two separate topologies. Filter 1 can do -12dB Vactrol or -24dB Transistor Ladder configurations from LP1 to LP4 with or without gain compensation, while Filter 2 can give you a -18dB Diode Ladder or -12dB State Variable Filter with HP2, BP1, LP2, BR1 and BR2 selections. All are resonant.
Grp Synthesizer A10: Envelopes and LFOs
The Grp Synthesizer A10 offers two ADSR envelopes for amplitude: one for each VCA. Yes, there are two VCAs, meaning you can treat it as two separate sound sources or one, massive stereo one. Each VCA has its own AM control as well. Additionally, each filter block contains its own bipolar envelope. Along with these main envelopes, there’s also an additional envelope follower for triggering off of external audio.
In terms of LFOs, there are three: two VCLFOs with five waveforms and an 11-position Shaping Select each, and a third with two independent VCAs for the two sections, plus waveform adjustment via control shape. There’s also a Sample & Hold circuit.
The A10 is also semi-modular with an internal routing system rather than patch cables.
Grp Synthesizer A10: Sound Source Processing
The A10 is the first instrument for Grp with integrated analog effects within the synthesis channel. You get two voltage-controlled wavefolders, a BBD stereo delay with independent synchronization across the two sections, two triple resonator filters, a dual phaser, and a spring reverb with two independent tanks.
Grp Synthesizer A10: Arpeggiator and Sequencer
You may have heard of Grp’s R24 sequencer. Now imagine that circuitry inside a synth. That’s what you get in the Grp Synthesizer A10: a 24-step sequencer with three rows of eight steps each. And yes, you can trigger the envelopes of each separate synth section independently (as well as pitch and various CV parameters).
The MIDI Arpeggiator gives you a different kind of control. You can assign it to the upper or lower parts when in Split mode or to the entire instrument itself. You can adjust the Pulse Width, Note Repeats, Octave Range and Advance Division to de-align the arpeggiator rhythm from that of the step sequencer.
Grp Synthesizer A10: Connectivity
In terms of connectivity, the synth offers a block of 57 plus two front audio and CV/Gate control connections as well as stereo balanced and unbalanced XLR jacks. There are separate outs for both upper and lower section as well as for headphones, and a mono in for processing external audio through the effects section. It also sports five-pin DIN and USB MIDI.
Grp Synthesizer A10: Price and Availability
The A10 from Grp Synthesizer does indeed look to be the “ultimate analog synthesizer.” Of course, there are no audio examples yet and we can only go off of the spec sheet and panel render. But it looks very promising.
It also looks very expensive. There’s no price announced yet but given Grp’s other instruments, it won’t be cheap. Grp Synthesizer hopes to ship the A10 in mid-2026.
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3 responses to “Grp Synthesizer A10: Is it the “Ultimate Analog Synthesizer?””
Grp really needs to call Axel Hartmann for some industrial design advice.
Noooooo!not yet another hartman design, they are ugly and repeting
Analogue Solutions called, they claim “Colossus” is the ultimate analogue synth.