GRP A8 – analog studio synthesizer „If you wanna start, start big!“ is what Groppioni Paolo (GrP) must have told me in 2008. We were sitting in front of a huge proxy of a synthesizer panel. In fact, the A8 – with 127 x 67 cm – is one of the largest synthesizers ever produced. It was built 22 times* and has been in studios in the USA, Switzerland, France, Belgium, Germany and Austria since 2010. [*After the production run ended, Paolo built a last GRP A8 for himself. So there are 23 instruments in total in existence.] Beside its monstruous size, it’s its concept that makes the GRP A8 awe-inspiring. More than that – I believe the GRP A8 has become a milestone in synthesizer history. While most modern analog synthesizers follow the concept of classic synthesizers, GRP has gone its own way. Fabulous sound is the basis, of course, but on top of this the GRP concept is tremendously flexible. There’s a fantastic intuitive user surface (with knobs instead of patches, so you’re faster), MIDI and (!) CV/gate, delightful performance features including the synchronization of all rhythm-based components (LFOs, S/H, auto-pan, sequencer …), and well … a wonderful – absolutely unique! – step-sequencer. | 1 GRP A8 – analog studio synthesizer GRP A8 – sequencer enabling section for VCOs, PWM and filter modulation Overview The GRP A8 is a dual section analog synthesizer capable of creating two entirely separate sounds. The instrument offers: 6x VCOs 6x sub-oscillators 1x noise (for audio and modulation) 2x ring modulator 2x 24dB lowpass filters 2x 12dB multimode filters 2x fixed filter banks 8x VCAs 4x DAHDSR envelopes 3x ADSR envelopes 2x VC LFO (with MIDI sync) 1x general LFO 3x audio-mixer 1x sample & hold (with MIDI sync and EG control function) 1×16 (2×8) step CV & trigger sequencer (with MIDI sync) 1x auto pan module 2x portamento reference tone (A=440 Hz) 9x audio out rear (Upper R/L, Lower R/L, Main Low R/L, Main High R/L, Mono) 6x audio out front (Main Low R/L, Main High R/L, Mono, Phones) CV – gate – trigger panel MIDI | 2 GRP A8 – analog studio synthesizer Impressive, don’t you think? Although: it’s not about counting oscillators and making you believe that tons of modules guarantee musical flexibility. Of course, the GRP A8 does all that! But the heart of this great musical instrument is its state of the art concept. VU-meter for UPPER and LOWER volume … Welcome to the beginning of the 21st century … Is it another Moog 55 clone you’re looking for? If so, then stop reading, you’re on the wrong boat. The GRP A8 is not modular. And thank God for that! All audio- and modulation-routings are pre-patched. No cables hanging around, no spaghetti …! The A8 is a futuristic analog studio system, creating a near-to-perfect performance environment. Using multi-selection knobs instead of patchcords guarantees a speedy workflow without loosing yourself in a jungle of cables. Generally, the A8 has 11-way switches for modulation purposes. VCO 1, for example, uses LFO 1, LFO 2, VCO 2, VCO 3, VCO 4, VCO 5, VCO 6, S&H, NOISE, EG 7+ or EG 7- as a source for FM. Just select the source you wish and off you go! While this philosophy of a modern patchwork instrument leaves you with, let’s say, 90% of a regular modular synthesizer’s possibilities, it compensates with an sinfully comfortable user interface. The GRP A8 reminds me a little of the legendary Oberheim Xpander: It gives you practically (well, 85%) as much control over voice architecture as even the largest modular synthesizer can offer – and then adds MIDI, full control over dynamics and synchronization, plus a superb step sequencer. Welcome to the beginning of the 21st century … | 3 GRP A8 – analog studio synthesizer GRP A8 – one of the two (well, actually three …) mixer sections Two synthesizers in one Imagine you with a heavy a 3-VCO (plus, let’s say, 2 sub-oscillators) Moog-like solo sound. Great, precious, analog! Two filters (in serial or parallel), a wide-range LFO (up to 2,2 kHz), three envelopes, a fixed filter bank … enough material to play around with for hours (and days, weeks, …). This is the UPPER section. Now press the start button and let the step sequencer take over control of the (identical) LOWER synthesizer. Jiggling a few knobs gets you a fantastic ring-modulation sound with some shimmering OSC-to-VCF FM. The sequencer-controlled ring-modulation sound follows every single note of the UPPER synthesizer Moog line. Turn on the auto-pan module (in bidirectional mode) and listen to the two sounds going left to right and vis versa. Switch the UPPER filter to velocity control and the LOWER filter to sequencer control. Now turn the LFO 1 modulation of the UPPER VCA to full right and synchronize auto-pan to LFO 1. You’ll also want some dynamic control over the LFO speed, so simply turn its FM CV source to velocity – voilà …! Tons of possibilities! So now it’s midnight (and everyone’s asleep) and you’re sitting there completely overwhelmed by the instrument’s potential. You haven’t even used sample & hold yet, and none of the two fixed filter banks … ah yes, and there’s noise, of course … and the additional 7th envelope. | 4 GRP A8 – analog studio synthesizer GRP A8 – S/H and noise While the GRP A8 is a complex analog synthesizer, it’s still very user-friendly! Sure, it takes a couple of days to get familiar with all those functions, but that won’t take forever. Once you’re used to the basic work flow, the musical potential is unbounding. The GRP A8 can be seen as a genuine 6-VCO mono-synthesizer, a flexible two-voice synthesizer with 3 VCOs each, a completely independant sequencer-workstation, a pure MIDI sound-tool, a classic CV/gate controlled machine – or a combination of any of these. Vintage synthesizer sound and state of the art performance Most of those great vintage synthesizers and modular systems from the 70s and 80s sound extremely beautiful. But they have their limitations. Either getting them MIDIfied is a nightmare or you can’t synchronize their (usually very basic) step-sequencer easily. There is no way to clock the vintage LFO to any other time based module and connecting a velocity sensitive keyboard might mean 30 minutes (and a few extra modules) to get it running … well … back to the Stone Age! | 5 GRP A8 – analog studio synthesizer GRP A8 – auto-pan module The GRP A8 offers the same vintage sound as the classic classics: deep, warm, analog. The fully discrete signal path lies at the base of its imposing sound. But the A8 is more than that … Highlights 1. Oscillators. 6 VCOs and 6 sub-oscillators are a luxury. Each VCO has 6 waveforms, going from 64’ to 2’. Individual tuning and fine tuning are both possible, of course. PWM may be done by one of the 11 modulation sources (among these: sequencer, aftertouch and velocity). Frequency modulation is possible in two busses: FM 2 uses the two main LFOs while FM 1 has the 11 modulation sources we mentioned earlier (these with comprehensive cross modulation functions). Oscillator synchronization is possible and the keyboard may be disabled for a “static” oscillator frequency. Each VCO has its own sub-oscillator 1 or 2 octaves below initial frequency. | 6 GRP A8 – analog studio synthesizer GRP A8 – massive analog oscillators 2. Filters. A total of four filters. Each synthesizer unit offers a 24dB lowpass filter (Moog style) and a 12dB multimode filter (Oberheim style) with HP, BP, LP and notch. The filters can be used independently (the 24dB anlone or the 12dB filter), in serial or in parallel. FM is possible via keyboard tracking, sequencer, velocity and an individual FM bus (again, with 11 sources to choose from). Each filter compartment has its own 6-stage envelope (a regular ADSR with delay and hold function). Keep in mind the A8 is bitimbral, meaning true stereo. Independent sounds (each with panorama control) – with, let’s say, slightly different filter modulation – guarantee impressive musical textures. The filters are marvellous. I often stick with just one 24dB Moog filter for a meaty and very powerful sound. High filter resonance settings enable unique timbres. This is classic analog pure. On the 12dB side, I’m especially fond of the notch filter. This is the sound of my Oberheim 4-voice in unison mode. Rare. | 7 GRP A8 – analog studio synthesizer GRP A8 – 24dB lowpass filter and 12dB multimode filter, LOWER synthesizer 3. VC LFOs. The two main LFOs are voltage controlled. Their frequency ranges from „very slow“ (to be honest, it could be even slower) to 2,2 kHz. We’re not talking about static LFOs, since speed modulation is possible by – you’ve already guessed – 11 sources: sequencer, key(board), the “other” LFO, EG (for those Yamaha CS-80 sound effects), modulation wheel, etc. Each LFO comes with its own envelope generator. This controls speed and/or modulation amount: SHAPING, GRP calls it. The EGs are 6-stage (with delay and hold function). There are 5 waveforms to choose from and LFO synchronization is possible – to GATE (any incoming key information, via MIDI or analog gate), to the “other” LFO, to sequencer or MIDI. Superb. 4. Synchronization. This is what I miss most on vintage analog synthesizers: the possibility to synchronize all rhythm-based (time-based) components.