Summer 2016. We’re on our way through the southern part of Sicilia, softly wistling Morricone’s great tune “Once Upon a Time in the West”. Gorgeous beaches, no, absolutely no shade. But a lot of sand and heat! We’ll be meeting Paolo Groppioni, who is vacationing in this aerea. With him a good friend: the new GRP synth!
The A2 is a true surprise. Not because it’s analog, and not because it can do this and that (it IS analog and it can do a lot), but because it exists in the first place. It’s as simple as that. Having the new GRP R24 sequencer in mind, we’re flabbergasted at the A2, suddendly lying there on the table. The perfect buddy for the sequencer. The same size, even the same housing. Gorgeous!
The A2 is unmistakably a GRP. Great hand-crafting, tricky features, an analog sound that is velvet and lush. New additions are an arpeggiator, the supersaw of oscillator 2, a single multimode filter that is capable of stereo, and various new modulation routings which we haven’t seen up until now.
Concepted as a desktop- or racksynth (rack-ears instead of the wooden panels), the GRP A2 can also be mounted into large modular systems (5HE) à la Synthesizers.com, Moon Modular, etc.* For that FAT voice, for instance. In other words: for that extra sound.
[* … with optional 5HE-MIDI/USB interface (front side), if desired.]
Visually, the GRP A2 has a striking appearance. Especially because of the illuminated VU-meters. And also because of the arpeggiator’s LED-chains.
Unfortunately (but necessarily) there’s an external power supply – something the size of the A2 demands. And in addition, the power connection for a modular synth is an internal prewire, so that the A2 doesn’t need the external PSU when mounted in a modular cabinet. That’s why the external PSU is the one – and only – perfect solution.
- 2 VCOs (oscillator 2 switchable to low frequ mode)
- 1 multimode VCF (HP, BP, LP, Notch)
- 1 ADSR (VCF), loop-envelope!
- 1 AR/AD (VCA)
- 2 LFOs
- Sample & hold
- MIDI IN / THRU
- CV/Gate and various other CV-inputs
- MicroSD-Card (firmware) inside the A2
The GRP-principle remains unique: all those switchable modulation routings offer (almost) endless sound possibilities. Have a look at the VCO graphic and imagine what sounds you’re able to create with those 11 FM SOURCES!
VCO2 has a nice extra: supersaw (which reminds us a little of the Waldorf Rocket). Supersaw stacks up to 8 sawtooth waveforms. The more you turn SHAPE clockwise, the fatter the sound! That also goes for sawtooth-triangle and triangle (see graphic).
The filter compartment is very powerful. Although it’s a single multimode-VCF (as opposed to the double filter of the A8 and A4), it is capable of true stereo! Switching to DIRECT mode, highpass appears at the right, lowpass at the left output. Modulating the VCF with one of the LFOs, this leads to stunning stereo-filtersweeps. (Now it’s time to listen to the attached soundfiles).
Our personal highlight is the NOTCH filter. It sounds like a phaser! Gorgeous, so to speak. (Soundfile DEMO2 is a mixdown of 4 notchfilter-tracks).
There are 2 LFOs. The first – VC Low Frequency Oscillator 1 – offers speed-control via KEY (the higher you play, the faster the LFO), EXT (analog CV-Signal attached to the A2) or LFO2. Envelope would have been another great modulation source, too, but well … it can be realized via EXT IN in any way. KEY SYNC is useful, resetting the LFO shape with every note you play. Modulation output of LFO1 can be at fixed level (HOLD) or can be controlled via AFT Touch or Mod Wheel.
LFO2 is quite different from its brother. Sure, it’s another triangle / square wave LFO, but it’s more than that. It offers 9 additional modulation sources (LFO1, VCO1, etc – have a look at the graphic). The trick is, that these modulation sources can be controlled dynamically via AFT Touch or Mod Wheel. Want some vivid VCO-to-VCF vocal sounds performed from your masterkeyboard? Move the wheel or press the keys harder according to the vocal timbre you desire …
2 envelopes: a full-scale ADSR and a cut-down AD/AR. The big one is for the filter and offers that great loop-feature first seen in the GRP A4 (ok, ok … also seen in the EMS AKS, EDP Wasp or OSCar many decades ago). The AD/AR is for the VCA.
The CV-inputs are tricky. Some of them are stereo-inputs, so you have two inputs (ring and tip) simultaneously. CV FLT (VCF) and LFO1 (speed control) share one input. CV AMP (VCA) and VCO2 share another one. Excellent features and very useful when having some modular synths in your studio, or when attaching an analog step-sequencer (the GRP R24, or any other as well) to the A2.
Arpeggiator and S/H have a dedicated clock input – nice! (The arpeggiator can also be synced via MIDI, of course.)
Performance and Extras
Ah yes, speaking of the arpeggiator … it has all the little niceties you’d expect, including some rare features like RPT (repeating each note x2 or x3) or the very useful PW Gate knob. SIZE acts as a clock divider, doubling the arpeggio speed from 4 to 8, te again from 8 to 16.
Switching the arpeggiator on/off needs some practice. You have to press the (tiny) CLK and SIZE buttons simultaneously to get it run, which isn’t that easy at times. But owning a GRP A2, you’ll learn quickly how to do it :o)
Two silver switches allow de-activating VCO1 (portamento and pitch bend). These features, in particular, are very important.
Imagine slow portamento affecting VCO2 only … drifting towards VCO1 until both oscillators meet up for that FAT sound. Imagine controlling the screaming part of VCO2 via pitchbender when both oscillators are in sync-mode. Imagine … imagine … there are plenty of examples!
Then we have a HOLD switch (very useful at times).
And a MIDI TO CV (off) switch, which simply allows to receive MIDI data, but disabling oscillator control. MIDI TO CV (off) makes sense in many ways … you might use the incoming GATE to clock the S/H, while S/H itself controls the oscillators … or you might run the VCOs via CV/Gate, but still want the arpeggiator to receive MIDI clock.
In a nutshell, the sound of the A2 is noble, powerful and dense. Interesting, by the way, that the GRP instruments sound more and more aggressive the smaller they get. The huge A8 is generally soft and modest. The GRP A4 has a sneaky sound that nicks you when you’re not looking. And the A2 engulfs you with one bite!
There’s absolutely no aspect of the analog sound spectrum which you would miss. Bass- and leadsounds have that cutting analog slash that’s not “every day” in the synthesizer world. We are especially surprised at the basses. Such depths as in the A2 we haven’t heard in a long time. (Listen to the attached bass-soundfiles).
The range of the effect sounds is infinite. Not just because of the all-encompassing modulation routings, not just because of the characters displayed by noise, S/H and the beautiful ring-modulator, and not even because of the two LFOs and the extra loop-envelope. It’s the sum of all those things that give the GRP A2 its extensive sound complexity.
At the same time – and that’s the most important of all – the basic sound of the GRP is both strong and magnanimous. All those little modulation routings and extras are nice, but none of them is worth a thing without a strong foundation. Listen to soundfile “DEMO1″ – a simple sawtooth sound with lowpass filtering and sample&hold modulation. Nothing really special, but it’s gorgeous (especially the colorful filter resonance). What more do we need?
For whom is the A2 designed?
… small to medium-sized recording studios demanding the acoustically unusual. Few analog synths of this size have a similar sound potential.
… larger studios with huge modular systems (5 units height, Moog size) demanding a complete analog voice. Take the A2 out of its housing, plug it in your modular system and away you go! That special GRP sound in your modular community. Out of its box, the A2 loses its MIDI ports, but there’ll be an optional MIDI/USB-interface (5 units height) for use in your modular system.
… live performers with good stage presence. The A2 doesn’t take up much room, is easy to transport and is a complete analog synth. Small is beautiful! Even more beautiful: the GRP A2 and the GRP R24 (both in the same housing). That synth-sequencer-couple reminds us of the the great vintage duo RSF Kobol I plus RSF Sequencer.
All in all
As with all GRP synthesizers, the A2 remains a high-quality instrument. Perfect hardware, versatility and flexibility, a sonorous sound. Great oscillators, great filter types, unbelievably modulation possibilities, ring-modulator, loop-envelope, VCF-overdrive … the creative musicians among you won’t miss a thing.
AND – ! – the GRP A2 is made in Europe. Unusual, to say the least. Which guarantees good quality. That classical cherry on the cake.
analog desktop/rackmount synthesizer
Price: 1200 Euros + VAT (22%),
wooden side panels and metal ears (for rack-mounting) included.
Production (1st run): early 2017
Delivery: starting June 2017
Optional MIDI/USB interface for use in a Moog-sized modular system:
MIDI/USB interface for A2-MIDI-control in a modular systems such as Dot Com, etc. The A2 offers CV/Gate control in any way, so you don’t need the separate interface, but since many functions (VEL/AT/MIDI CLK) are MIDI-based, it might be wise ordering the MIDI-interface as well. (Only necessary for use in a big modular system.)
Orders / reservations –
contact Paolo Groppioni (GRP), email:
Website manufacturer: www.grpsynthesizer.it
Download / open:
Further GRP instruments:
We attached 50 minutes of audio material. 85% of what you hear is the GRP A2. Then there’s the Korg monotribe (contributing some drum-patterns) and the classic Roland D70 synthesizer (for pads and atmospheres). We strongly recommed the use of high-quality speakers or headphones – in order to hear the “extra low low-end” of the GRP A2 …