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Analogue Solutions Vostok

Analogue Pin-matrix Synth By Paul Nagle
Published January 2003

Pin-matrix synths, like EMS's legendary VCS3 and Synthi A(KS), are fairly scarce these days, but Analogue Solutions' Vostok revisits the concept in a more affordable form. Is it a vintage-inspired classic, or is it just history?

Analogue Solutions Vostok pin-matrix synthesizer.Patching connections with the pin matrix. Only those with a steady hand and good eyesight need apply!If you know something of the history of synthesizers, the mere mention of a suitcase-based analogue synth featuring a pin matrix, a signal meter and joystick might just ring a few bells — and if not, check out SOS December 2000's Retrozone, wherein the history of EMS's Synthi A and AKS is discussed in some detail. Analogue Solutions are at pains to point out that their latest creation, the Vostok, is not intended to sound like an EMS clone. Nevertheless, they have cunningly devised an instrument that offers many of the features that made (and still makes, as EMS are still in business to this day) a Synthi A or VCS3 much sought after. Although the Vostok is not physically modular in design, its individual components are sourced from Analogue Solutions' range of modules, and as only one is internally patched (the signal meter), you first need to connect the various bits of the synth together with patch cords or its pin matrix before you hear anything.

Casing The Joint

Images on the Analogue Solutions web site don't prepare you for the Vostok's diddiness — it's the Toulouse-Lautrec of synths! The black plastic case is particularly lightweight, and is not intended as a replacement for a true flightcase. The construction left a little to be desired, too — sharp bare screws were left exposed on the review model, sticking through the lift-off front cover, as you can see above. With the cover removed, the Vostok measures just 44 x 27 x 13cm — so it would occupy very little space in a studio or live rig. The case accomodates the equivalent of two rows of 85HP (1HP — Horizontal Pitch — equals 0.2 inches or 5.08mm), and is also available separately, meaning that you could buy one and stock it with modules of your own choice from the range of compatible modulars by other companies, for example the unrelated Analogue Systems, and Germany's Doepfer. Power is supplied by a conventional mains supply, and its large green illuminated On/Off switch is positioned on the left-hand side of the case (see picture towards the end of this article).

With its red-tipped knobs and red-and-white lettering, the Vostok has a certain brash charm, although the Cyrillic-style front-panel legending takes some getting used to. In operation, it can be placed on its back for table-top use or, more typically, it can stand upright on its rubber feet.

Analogue Solutions Vostok £1644
  • An interesting collection of modules in a convenient package.
  • Pin matrix and patch connections for maximum flexibility.
  • Good basic tones and rip-roaring filter.
  • General calibration problems found throughout the review unit.
  • Matrix not fully buffered.
  • MIDI interface rather basic.
  • Digital oscillator of limited value.
  • Rather expensive, given the above issues.
A complete synth in a suitcase, featuring a pin matrix, sequencer, joystick and MIDI. Although not cheap, here is a machine well suited to creating weebly noises, manic analogue sequences or squelchy bass sounds. Currently, there isn't anything that's going to do these things quite like the Vostok.


The Once-Over

It's immediately evident that the Vostok takes the Swiss-army-knife approach to synthesis, offering a generous array of tools. A MIDI interface is provided (so you can drive the voltage-controlled Vostok from a modern sequencer — see the 'Vostok & MIDI' box opposite) along with two VCOs, two LFOs, two envelope generators and a filter featuring resonant high- and low-pass sections. A third oscillator (based on digital wavetables), plus a step sequencer, ring modulator, joystick, signal meter, mixer, multis and noise/sample & hold, all add up to a comprehensively stocked toolkit. The pin matrix is supplemented by extensive 3.5mm mini-jacks for ease of connectivity with other modular systems. Should you want the Vostok to talk to larger-format synthesizers, two quarter-inch adaptor jacks are provided, and the main output is also offered in quarter-inch format — all the better to plug into your mixer with.

The Matrix

Probably the most eye-catching and innovative feature of the Vostok is its 22 x 22 pin matrix: a good enough place for us to kick off our tour. This tiny grid (around seven centimetres square) offers access to most of the Vostok's signal routing and, by lining up source and destination, you can assemble a complete patch without all that messy cabling. Indeed, as no cords are supplied, it will probably be to the 15 included matrix pins that you turn first in order to make some noise.

Each pin has a 10kΩ resistance and multiple connections can be made to the same source or destination without drastic loss of signal. The pins are small and you need a good eye to accurately link up the inputs along the top of the matrix with the outputs that run vertically. The two types of signal — control voltages and audio voltages — are grouped logically together in the matrix. Audio Signals and CV Outputs are labelled by named function down the right-hand side of the matrix and by numbers down the left side (see below). Similarly, the upper axis is labelled using meaningful names, its lower half by the letters A-V — with no obvious correlation between names and letters. Naturally, this being a voltage-controlled synth, you can patch audio signals into voltage inputs and vice versa.

According to the manual, all the signal and control outputs are buffered, and many of the inputs too, although despite this, I did experience voltage drops when making some connections, such as plugging the output of an LFO into the CV input of a VCO. Analogue Solutions have since confirmed that not all of the matrix connections are buffered, so expect a degree of unpredictability!

Some of the connections not present in the matrix include the VCO1 sawtooth output and sync input, plus the VCO2 square-wave output and pulse-width CV, but, on the whole, the matrix encompasses most of the synth's functionality. In theory, you could patch into the same modules with cords and the matrix simultaneously, although the onus is on you to be well organised and avoid making conflicting connections. Experimentation is the key to understanding most modular synths, and, if anything, this is even more relevant with the Vostok.


Two VCOs act as the main sound sources, and provide simultaneously available sawtooth and variable square waves. A dedicated pulse-width knob sweeps the latter from a narrow pulse through to square and back. External control of pulse width is also provided, with amount of modulation being determined at the CV source rather than destination. Actually, many Analogue Solutions modules have output amounts set in this way; thus the oscillators have dedicated output levels for each waveform, and the mixer has no controls at all.

Both oscillators have dedicated Glide knobs so they can slew at separate rates. Unfortunately, the review model's oscillators had a small amount of glide present all the time, even when the control was set to zero. Analogue Solutions claim that this will be dealt with on all Vostoks built from now on, but early models may suffer from this 'feature'. I'd have liked a fine-tune knob to have been included too, since the single control present, with its available range of plus-or-minus one octave, made subtle detuning a little awkward. A sync input jack is present for both VCOs.

Oscillator 3 seemed, on paper, to be the most interesting — a digital eight-bit wavetable oscillator featuring no less than 256 waves in 64K of memory. The four-character 'bubble'-type LED has, apparently, been selected for its retro look (see right). It's fairly readable (though would possibly look better behind darkened glass, Sinclair watch-style) and displays the note name and wave number (in hexadecimal). The initial wave can be selected via a knob and these proved to be full of digital fizz: buzzy noises, mellow organs, and clavinet sounds issued forth, all with a healthy dose of aliasing artifacts. A switch selects between bank A (waves 0-127) and bank B (waves 128-255) and there are also CV inputs to perform wave and bank selection via external control.

Analogue Solutions Vostok suitcase synth.A complete synth in a suitcase, featuring a pin matrix, sequencer, joystick and MIDI.I eagerly patched in this module, thinking of my happy experiences with the digital oscillators in my Digisound modular and my recently acquired Dave Smith Evolver. However, it was only after some time struggling to get the Vostok's digital oscillator to play anything like a melody that I checked the manual, and noted the significant statement 'VCO3 works best when used with the internal analogue sequencer'. I duly connected the sequencer and tried stepping through oscillator's pitch and waveforms automatically with it. Only then did I start to hear hints of how cool this oscillator could have been, had it only been possible to give it more accurate tuning. The oscillator has a range of four octaves, and does its most interesting stuff in the lower ranges. Ultimately, I'd have to sum it up as a curio suitable for weird noises, or for its aliasing and stepped waveforms, rather than a vital inclusion as a musical sound source.

LFOs & Envelopes

Two LFOs offer a selection of sawtooth or inverted sawtooth plus square or triangle waveforms. An ingenious selection method, and one seen on previous Analogue Solutions products, is via knobs that pull outwards from the front panel, thereby acting as switches as well as knobs (and before you look at the pictures accompanying this article, it's not obvious from just looking at the controls which ones pull out and which don't). So, for a conventional sawtooth, you push the knob in, and for an inverted sawtooth, you pull it out. Then, in simple but effective fashion, turning the knob sets the output level of the selected waveform. A voltage input is provided so you can vary the LFO rate using another LFO, envelope or whatever. The minimum speed wasn't nearly slow enough for my tastes (until I patched in a negative voltage to slow it down) but I guess as soon as you make someone like me happy with a very slow LFO, someone else will complain it doesn't go fast enough. The manual doesn't specify the LFO range, but it does reach audio levels at its highest frequency.

The two envelopes seemed, at first glance, to be straightforward ADSR types. Envelope one has a green LED which lights to show it has received a gate, while envelope two has a yellow one — and each has a bi-polar control for amount. Each envelope also has a repeat function, and this I disliked instantly. Don't get me wrong — I love repeating envelopes — but the ones present on the review model leapt into repeat mode not at a zero sustain setting for each envelope (as designed) but at settings far higher than that. Apparently Analogue Solutions are exploring the possibility of fitting a separate switch to engage the Repeat function; as it was, I found it impossible to set the envelopes so they were suitable for snappy sequencer work.

 The Vostok & MIDI 
 The Vostok includes a basic MIDI interface which generates a gate signal and two CV signals based on incoming MIDI events. As well as a MIDI In socket there is also a Thru and, usefully, you can activate the module's trigger output manually with a dedicated button. Setting up the MIDI channel is as easy as pushing the MIDI program button and either playing a note or moving the mod wheel on your connected controller. Thanks to the interface's built-in Learn function, the MIDI channel on which the incoming data is received is the one stored, and when you play a note to initialise the interface, CV2 is set automatically to output a signal derived from velocity. You can no doubt guess that moving the mod wheel instead sets CV2 to produce a signal based on the MIDI controller sent by the wheel. Either way, CV1 always represents the MIDI note value.

Other than that, the MIDI interface has just two additional outputs: Accent and Legato. The former outputs a voltage of 5V when it receives a note with a velocity higher than 81 (the synth's panel says the velocity threshold is 100, and the manual claims 79), returning to zero only when a velocity of less than this is received.

I got useful results using the signal generated by the Accent jack as a clock source for the sequencer. With it, gentle playing does not advance the sequencer steps, but forceful playing does — so you can choose when to introduce a variation in tone intuitively as you play. The Legato socket outputs a 5V signal when any notes overlap and returns to zero when none are overlapping.

Neither of the oscillators in the review model tracked my connected MIDI keyboard very well, leading to noticeable pitch variances over just a couple of octaves and restricting the range over which the synth was playable. At first I thought that the oscillators themselves were not scaled correctly, but they proved quite accurate when I removed the Vostok's MIDI interface from the equation and played them via my Roland SH101's CV outputs. Fortunately, scaling trimpots are available on the MIDI interface's front panel for some degree of fine adjustment.

And that's about it for the MIDI interface. It doesn't respond to anything else (say pitch-bend or aftertouch) and the manual is quite clear that it is aimed at sequencing.


Filter & VCA

The filter is none other than Analogue Solutions' 12dB-per-octave SY02 — itself based on the Korg MS20 filter. I found this dual high/low-pass filter to be an excellent choice, and a pleasant change from yet another Moog clone. Indeed, it was already my favourite Analogue Solutions module, and has long had its place in my own modular system. The Vostok's version lacks some of the input jacks of its ancestor, having just one CV socket each for the high- and low-pass filters. However, as these inputs are also found within the pin matrix, you can add multiple modulations that way rather than by using the single, overworked mixer.

Use of the high-pass and low-pass cutoff controls together gives a very flexible band-pass filter, and having independent resonance for each is a source of awesome wibbly noises or more subtle solo patches. The filter can also be overdriven quite easily, and sounds pleasantly dirty when you do so. Think 'The Corrs in a mud-wrestling contest', if that helps in some way. The review model seemed to go into self-oscillation even more easily than my own SY02, and screamed like a banshee at the slightest provocation — this is one aspect of the Vostok that gets an unreserved thumbs-up from me.

The integrated VCA features an initial level control that you can use when fading in drones and the like (more conventionally, you'd connect an envelope to its CV to shape the output). The main volume control resides here too, and the signal output is available in both 3.5mm and quarter-inch formats — a nice idea.


I briefly alluded to the sequencer earlier when discussing the digital oscillator, and if you think a mere eight steps don't add up to much fun, think again. Step sequencers are more about control and immediacy than hammering out long complex patterns, and this one is no exception — it adds considerably to the Vostok's appeal. Programming is accomplished by simply spinning the knobs during playback or, for more accurate tuning, by adjusting the knobs one at a time before setting the sequencer running, while stepping manually through the sequence. To program a riff where the sequencer's CV is routed to pitch, for example, you push the button, tune the step via its knob and move on to the next step until your sequence is complete. Running the sequence requires that you patch in an external clock source (there is no built-in sequencer clock) such as an LFO's square wave. However, very interesting (and not entirely predictable) things happen when you clock the sequencer with other waveforms, such as a sawtooth or triangle wave. Using some of these alternatives, the sequencer direction can vary wildly and, depending on the cycle of the LFO, can suddenly start to go backwards, skip forward several steps or even replay the same step for a while. If you want to break up the rhythms generated, pulling out any individual knob turns that step into a rest (that is, no gate signal is generated). Progress through the sequence is indicated by the blinking yellow LEDs and, anorak that I am, I found it entertaining to keep the sequencer running at all times, even when not controlling anything. Hey, I'm surely not alone in my love of flashing lights!

A switch determines whether the CV range produced is between 0 and 10 or 0 and five Volts. The latter makes it easier to tune melodic sequences, but the former might be of more value for large control changes. The sequence is restarted whenever a trigger is received at the Reset jack and this made me think that individual trigger outputs for each step (as on Korg's SQ10 for example) would have been really handy — that way you could reset the sequence at any step by patching the step's trigger out to the Reset jack. As it is, only the output from Step 1 is available. The clock input also features a Thru jack, which is ideal if you have multiple step sequencers or wish to allow the clock signal to continue, perhaps to drive the sample-and-hold module.

The CV signals produced by each step of the sequencer can, of course, be directed to any CV input. The gate output is useful too, especially if you have some of the steps set to be inactive; as a simple example, you could trigger the envelopes alternately by using the sequencer as a middle man for one of them.

Don't forget that sequencers needn't always produce robotic loops. They can also be used to introduce subtle timbral variations if you clock them from each note played and direct their output to pulse width, or a filter control voltage, say. Or, if clocked from an audio-level source, they can be used to generate unique waveforms.

Other Modules

The Vostok crams a lot in, and here are just a few words about its remaining components.

  • The mixer is a simple yet vital module, capable of merging up to six inputs and having both a positive and inverted output. So, if you mix control voltages you gain access to both positive and negative modulation sources simultaneously. The mixer can handle audio or CV sources.
  • The backlit moving-coil meter is an improvement on Analogue Solutions' original module — simply because that had no light. The manual reminds us that this is not a precision device, but is handy all the same for monitoring audio or control signals. It measures positive voltages only, and is permanently patched to the positive output of the mixer.
  • The joystick feels reassuringly smooth and has CV outputs (with individual amount controls) for the X and Y axis. It has enough resistance to use with confidence and remains in position when you release it — just as you'd want. Its maximum range is ±12V.
  • Two simple 3.5mm-to-quarter-inch adaptors are provided, with one of them available in the matrix. And, for multiple connections, two handy 'multis' (labelled 'split') are available, with four connected sockets each.
  • A combined noise source and sample & hold module features controls for noise level and slew amount. To create an S&H modulation source, connect the noise to the S&H input, then pipe in a clock signal and you're away. Slew smooths the output from the module for less drastic changes.
  • A ring modulator is also tucked in neatly next to VCO1 and reminds me how nice it would be if the main oscillators had produced sine waves — the ideal source of those pure ring-modulated 'bell tones' we all know and love.


Drawing any meaningful conclusions about the Vostok requires that we consider who it's really aimed at. Such an eclectic collection of modules (try saying that after a few pints of Old Scrotum) indicates a laudable desire to do something slightly out of the ordinary. Analogue Solutions have shown that it is still possible to rediscover underexploited backwaters of music technology and produce something that is both new, yet reminiscent of classic designs.

However, at over £1600 including VAT, the Vostok isn't a cheap synthesizer, and when you bear that price tag in mind, you start to look more closely at some of those rough edges, the calibration issues and technical imperfections. Personally, I'd expect something that exuded a little more quality if I were handing over such a sum. I'd certainly insist that the issues with the envelopes and oscillator pitch were resolved, but I also think it not unreasonable to demand a more fully featured MIDI interface, and perhaps a more robust case too. It also occurs to me that the Vostok's price tag is not a million miles away from the price of a brand-new EMS Synthi A (amazingly, these can still be ordered from EMS for around £2100 including VAT, although there is a waiting list).

In fairness, Analogue Solutions have claimed that some of the issues I raised during the course of the review, such as problems with oscillator glide and envelope repeats, will be dealt with before future Vostoks are constructed. As a small company, they certainly have the freedom to do this, although nothing definite was in place before the end of my review. It's also possible that these problems are less significant to some potential punters than they would be to me. For, make no mistake, this is a synth with a specialised appeal and the Vostok's behaviour, range of sounds and performance undoubtedly does bears comparison with those classic EMS instruments. It scores by being slightly cheaper and having such extras as a MIDI interface, a sequencer, mini-jack connections and more. The VCOs sound fine, the filter marvellous and even the digital oscillator could be the source of some very strange sound effects or funky, wave-changing sequencer loops. I mean it as no insult to say that it could be an awesome self-contained sound-effects machine. In that context, the Vostok could do just fine.

infop.gif £1643.83 including VAT.
infot.gif Analogue Solutions +44 (0)1384 353694.