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Lassence µVentury II

Patchable Analogue Modular Synth System By Gordon Reid
Published May 2003

Belgian company Lassence are seeking to gain recognition as a small modular synth manufacturer with their new patchable µVentury II system. But there's plenty of competition in the homegrown analogue market these days. Does the µVentury II have what it takes?

The µVentury II intrigued me for two reasons; partly because prior to 2003, I had never heard of it, and partly because, when I first clapped eyes on its international distributor's web site (from which it is sold via mail order), I thought that it looked unlike any other analogue synthesizer I know. These days, when one synth is often very like another, that was more than enough to get me interested...

Lassence µVentury II main photo.First things first. The µVentury II is a modular synth, so you'll need to start patching its various sections together before you'll obtain a sound. Nonetheless, it looks nothing like the rash of systems now provided by Analogue Systems, Doepfer, MOTM, Modcan, or any of the other manufacturers now satisfying our craving for things that go bleep in the night.

Housed in a natty little outer case (from which it is easily removed) the µVentury II looks less like a synth and more like a remote mixer, as used for outside broadcasts. These little mixers, which often only have as few as four input channels, usually cost many, many times the prices of their low-cost cousins from music-industry manufacturers such as Boss and Behringer. So why do people buy them? Because, when the sound engineer drops one in a muddy field halfway through the director's favourite take, there's a chance that it will carry on working as if nothing had happened. And so it appears to be with the µVentury II.

Lassence µVentury II
  • Good, solid sound.
  • Robust construction.
  • Quality controls and sockets.
  • Looks and feels good.
  • Quarter-inch patch jacks.
  • Five-year warranty.
  • Cannot easily be tuned.
  • The review unit's VCOs do not track at 1V-per-octave over a sufficient range, nor do they track equally.
  • No pulse wave other than square, and no PWM.
  • Filter does not self-oscillate.
  • Insufficient patch points, multiples, and mixers.
  • Poor scaling for the ADSR controls.
  • Although a revision is apparently planned, the manual is currently very poor.
The µVentury II is a brave attempt to produce something different in an overcrowded synth world. Some aspects are weird and fun; others are weird and no fun at all. It's also limited in what it can do, and expensive compared to the competition, so while there may be a small number of people who might love it, I suspect the majority of the hi-tech world is going to pass it by.


What's It Got?

The top panel is secured by four torx screws, which require special drivers if you are to remove them without making a mess of things. This is good for keeping prying fingers out of the guts of the synth. As for me... I knew that my Apple service tools would eventually come in useful for something.

Inside, you'll find nine boards mounted to the top panel using the quarter-inch sockets and control knobs as fixtures. This means that each board is secured at six or more points, and they show every sign of staying where they are (muddy fields or not). The boards themselves are single layer and sparsely populated, and the only other thing in the case is the power supply. Lassence claimed in their early publicity that they avoided the use of buss power distribution in the µVentury II, suggesting that this would lead to problems with unwanted noise and rumble. However, the power cable for each board comes from a connector mounted on the previous: in other words, the power distribution is a buss. I contacted Lassence about this, and they claimed that having failed to encounter any of the noise problems they had anticipated, they eventually built the finished version of the µVentury II with buss power distribution. However, it seems that they forgot to change their publicity and web site to reflect this. Their intention is now to change their literature. However, if you read their early promotional material, it's worth being aware of this point.

µVentury II front panel.At first glance, the µVentury II is not flush with facilities. The front panel offers just two VCOs (called 'Generators'), a VCF (the 'Vc Active Filter'), an external input section, something called 'Wave X' (of which more later), a single contour generator, two ring modulators, and a three-way multiple. Oh yes, and a little signal level meter. There's no obvious VCA (but again, more of this later...), no dedicated LFO, no noise generator, no mixers, no slew generator, no sample & hold, and none of the esoteric functions that can make modular synthesis so much fun.


Each of the two VCOs offers a 'Hi' (audio) and 'Lo' (LFO) mode, with the simultaneous output of two waveforms, the shapes of which are controlled by a single Wave Select knob.

The manual says that the waveform generated at the 'Saw' output changes from a sawtooth wave at the knob's anticlockwise extreme to a ramp wave at the clockwise extreme. It makes no mention of what you might find in the middle, although one might reasonably assume that it is a triangle wave. However, the manual is incorrect.

At its anticlockwise extreme, the output is a sawtooth wave as promised, and it's a good one... as accurate as one might expect from a synth of this type. But as you turn the knob toward clockwise, the waveform assumes the form of a sawtooth with lumps bitten off every other peak. One consequence of this is that the pitch in the middle of the knob's turn is an octave lower than at the extremes (because the wavelength is doubled). Figure 1 (above) shows the output at the 12 o'clock position. It's all very strange!

Figure 1: Halfway between saw and 'ramp'.Figure 1: Halfway between saw and 'ramp'.Turning the knob fully clockwise reveals something close to a triangle wave, but of much lower amplitude than the sawtooth and intermediate waves. Of course, this is where the ramp wave should be, but once you understand what's going on — and learn to ignore the manual — it all works.

Further investigation shows that the sawtooth and triangle waves are indeed oscillating an octave above the oscillator's fundamental frequency, and the wave shown in Figure 1 lies at the same pitch as the square wave.

The manual's description of the Square/Sine output is rather more accurate and, at the anticlockwise extreme, you obtain something that is close to an ideal square wave. However, its pitch is an octave lower, and the amplitude is much higher than the sawtooth wave.

I again contacted Lassence about this, and they claimed that they had deliberately designed the triangle wave to be at a lower amplitude, so that when mixing the oscillator outputs at the filter, there was less chance of overloading it and producing distortion. This makes no sense to me. If there is a risk of unwanted distortion, why restrict the remedy to a single waveform?

Figure 2: Halfway from square to sine.Figure 2: Halfway from square to sine.Further strangeness manifests itself as you move the Wave Select control from the Square setting at the left end of the knob's travel towards the Sine at the right extreme. Rather than rounding off the waveform progressively, or low-pass filtering it down to the fundamental, the first half of the knob's turn smoothes the leading cusps off the wave (as shown in Figure 2). Continuing to turn the knob smoothes the trailing cusps to produce something akin to a sine wave. It's more weirdness, but the results are acceptable.

Each VCO is controlled by two pitch CVs; an ostensibly 1V-per-octave CV input, and a modulation CV which is attenuated by the Mod Ctrl knob that you'll find below the Frequency control.

The VCOs' frequency ranges are generous, with claimed ranges of 0Hz to 50kHz in Hi mode, and 0.01Hz to 500Hz in Lo mode. Unfortunately, there is no A440 tone generator, so it's impossible to tune the µVentury II to concert pitch without reference to an external source. Curiously, the Frequency knob is also calibrated unconventionally, with higher frequencies obtained as you turn the knob anticlockwise — a somewhat counter-intuitive design decision.

However, of more concern to me is the fact that the huge frequency range at your disposal exists in a single turn from about five o'clock back to seven o'clock (anticlockwise, you see), making it all but impossible to tune the oscillators to precise frequencies. Worst of all, the two oscillators do not track incoming CVs at 1V per octave, and they go significantly flat as you play higher up the keyboard. They even track at slightly different rates, so they go out of tune with one another even as they go out of tune with everything else. This makes it impossible to use the µVentury II for musical duties, as opposed to the creation of sound effects. I've seen a demonstration of another µVentury II that tracked rather better over the length of a four-octave keyboard, so maybe my review model was a poor example, but the demonstration unit was still significantly flat by the time the player reached the top end of the keyboard. Lassence have suggested that my µVentury II might have been knocked out of calibration during shipping from Belgium to the UK — the internal tuning pots are apparently fairly sensitive — but because the synth can only be brought via mail order at the moment, this is a problem that might affect any potential Lassence customer.

 It's good to see a manufacturer show confidence in the long-term reliability of its product, and this is one area in which Lassence score highly, offering a five-year warranty on all parts and labour. Very nice! 

The Filter

Until you delve further, the 12dB-per-octave voltage-controlled filter looks fairly standard. There are two inputs, and an Input Level knob controls the level of the signals presented to the In (Hi) input. In (Lo) has no such control, but you can balance the signals from the two inputs by turning the Level control just a few degrees from zero. Given that the µVentury II offers no other mixer, this is not a luxury... it's a necessity.

Next come the expected controls for Frequency and Feedback (which is just another name for resonance). Moving on, two attenuators control the level of the signals presented to the Mod1 and Mod2 inputs, so you can patch some sophisticated filter modulations, although there is no provision for CV control of the modulation depths. The manual describes these inputs as 'typically 1V-per-octave sensitive', but this is again incorrect; at maximum mod, the filter tracks a keyboard CV at a far greater rate. Although it's possible to set the knob so that the tracking is closer to 1V-per-octave, it's very fiddly, because the correct setting is somewhere in the middle of the travel of a continuously variable knob. Perhaps it would have been better to say that it is possible to set things up so that the inputs track at approximately 1V per octave. However, the whole discussion is perhaps moot, because the filter does not self-oscillate, and the µVentury II offers no noise generator to create those delicious 'tuned noise' patches produced by many of the better analogue synths.

So now we arrive at the filter knob marked Low/High. To understand this, we need to look at the filter's outputs, of which there are no fewer than four. Three of these Low, High and Band — are self-explanatory. The fourth is Vari (the 'variable' output) and the manual simply, and not very helpfully, states that this offers "a smooth transition from low-pass to high-pass filtering". The nature of the output at any given time is determined by the Low/High knob and, as far as I can tell by ear, the transition state is a notch of some sort.


Lassence µVentury IIPhoto: Mark EwingNext to the filter you'll find a section that seems to be marked 'External Wave X'. This is confusing because 'External' and 'Wave X' are actually separate sections, and although Lassence have sensibly delineated all the other sections on the µVentury II with lines on its front panel (for example, to separate the Generators from the Filter, and the Contour from Wave X), they've not done so here. Still, it doesn't take too long to work this out.

External offers 'In (Lo)' and 'In (Line)' input jacks, both with preamplifiers (controlled by the Mic and Line knobs respectively) and outputs that allow you to direct the amplified signals to other sections of the synth. The Line output is also linked to the Envelope Follower and the Trigger Generator...

Hang on a second. Who said anything about an Envelope Follower or a Trigger Generator? Surprisingly, the µVentury II has both. In normal use, you present the signal of your choice to the Line input, and derive the envelope and Gates from the 'EF' and 'Trig' outputs at the bottom of the section. The Env Sens knob in the middle of the panel then determines the module's sensitivity to the incoming signal.

Alternatively, you can present a modulating signal to either or both of the 'EF In' and 'Trig In' sockets. These break the internal patching of the follower and trigger generator, allowing you to present an audio signal at the 'In (Line)' jack and chop it up using other sources such as LFOs, or even other audio signals.

Unfortunately, the 'EF In' jack on the review µVentury II appeared to be faulty, and I found that the 'Trig In' jack drove both the follower and trigger generator. Nonetheless, assuming this to be a simple fault on the review model, there's potential here, although the patching remains rather limited.

Wave X

Figure 3: Wave X output with a sine wave input.Figure 3: Wave X output with a sine wave input.Moving on to the Wave X section, little information is available in the manual to tell you what this is for. It says that the module 'was designed to increase the harmonics content of sine waveforms', but that's not very specific.

The only way to find out what was happening was to take some samples, so Figures 3 to 6 (below) show what Wave X can do to each of a sine wave, a sawtooth wave, a triangle wave, and a square wave.

Figure 4: Wave X output with a saw wave input.Figure 4: Wave X output with a saw wave input.The resulting sounds are interesting, especially when the Wave X amount is swept by an LFO or envelope applied to the CV Wave input, but unfortunately this input is very fussy about what it will accept as a CV; in fact, nothing on the µVentury II had any effect upon it. At first I thought that the µVentury II was faulty again, but when I used an external DC level-shifter, I was able to raise the voltage sufficiently to drive it, at which point I discovered that the Wave knob in this section doubles as a CV level control. This, too, is not mentioned in the manual.

Figure 5: Wave X output with a triangle wave input.Figure 5: Wave X output with a triangle wave input.Lassence claim that the CV Wave input is designed to take a wide variety of input signals, but if nothing on board can drive the input, and it cannot be used without additional equipment, this is not a trivial matter. Waveshapers are quite boring modules unless you are able to apply controllers via VCAs to make their effects dynamic. Without these, a waveshaper is just a static device that produces odd waveforms. Useful, perhaps, but far from earth-shattering.

Figure 6: Wave X output with a square wave input.Figure 6: Wave X output with a square wave input.By the way, the eagle-eyed among you might be wondering how I got the audio signal into Wave X in the first place. After all, a close look at the panel confirms that there is no input. To do so, you actually push a quarter-inch jack about halfway into the filter's 'In (Lo)' socket. The manual claims that this is 'probably the first time in synthesizer history that this method has been used'. I wonder why? (No I don't).

Contour, Ring Mods, Meter, Auxiliary & Multiple

Next on the front panel comes the contour generator, a conventional ADSR controlled by a Gate. It's reasonably snappy, with claimed minimum A, D and R times of 2.5ms and maximum settings of 20s, but you'll find that rather too much of the useful range is concentrated in the first few degrees of turn. This makes it hard to program it precisely, although it gives you lots of room to experiment with languorous sweeps if you wish.

To the right of the contour generator, you'll find the final group of modules. Again, there is no silk-screening to differentiate the sections on this part of the panel, but at least it's clear what the X Input, Y Input and Ring 1 Out are; they're the inputs and output of an AC-coupled ring modulator.

There can be dramatic differences in quality between different ring modulators and, to my ears, the unit in the µVentury II is one of the better ones, producing well-differentiated and clean output signals. However, when using the one on the review model to create new timbres to play from a keyboard, I was hampered by the aforementioned difficulty in tuning the oscillators, and their inability to track equally.

Beneath this, the second Ring Modulator is DC-coupled, which means that not only does it create the X+Y and X-Y signals of the AC-coupled device, but also passes the original X and Y sources. The output therefore contains four partials, and can be particularly clangorous.

However, DC-coupled modulators have an important side effect. When modulated by low-frequency signals and aperiodic signals such as envelopes, they act as VCAs. So the µVentury II's second ring modulator doubles as its only VCA. It may seem odd, but it's an acceptable — if limited — way of doing things.

To the right of the modulators, you'll find the Volume control and its associated Aux Out socket. Contrary to expectation, the knob is not an output volume control in the conventional sense. Instead, it taps the signal carried by the filter's 'Vari' output, attenuates it and presents the result at the Aux socket. In other words, this part of the µVentury II is patched internally to avoid its own VCA. Alice was right. Curiouser and curiouser.

The penultimate component in the µVentury II's armoury is a signal-level meter that is hard-wired to the low-pass output of the filter. This is yet another anomaly; the meter does not reflect the signal level carried by the output and volume control alongside it, nor can you use it to measure any other signal levels within the synth. Sadly, this reduces its usefulness to purely decorative levels.

Finally, there's a three-way multiple that allows you to mix two signals into a single output, or split a single signal into two outputs.


Like me, you may not have heard of Lassence before. This is not surprising; the company's main activities apparently lie in the fields of data management and management consultancy. In parallel with this, the owners have pursued their personal interest in synthesis, collecting a small number of interesting synths, and opening a Belgian dealership for Analogue Systems and Macbeth Systems.

Exercising their fascination with analogue — and preferably modular — synthesis, the chaps at Lassence next contacted Fabrice du Busquiel, the designer of the µVentury II. Discussions clearly went well, because Busquiel made the company the exclusive worldwide distributor for the product. Lassence now say that they wish to expand the range and import other analogue synths from around the world, and to distribute them across Europe.

In Use

Lassence make some pretty lavish claims for the capabilities of the µVentury II, stating that it is "groundbreaking, breathtaking and non-conventional" and that you should "forget almost everything you know of analogue synthesis and enter a world of experimental sound generation". I think most people will find it rather more limited than these claims suggest. For example, a pair of oscillators/LFOs is not really adequate on a machine of this price. You're limited to either two audio VCOs and no LFOs, one audio VCO and one LFO, or no audio VCOs and two LFOs. Likewise, the absence of any pulse waves other than square, and the lack of pulse-width modulation limit the timbral range of the µVentury II.

In a similar vein, I found the number of mixers, multiples and VCAs inadequate. For example, if I use the multiple to receive a keyboard CV and direct it to the pitch CV inputs of the two oscillators, then if I wish to direct the ADSR contour to both the VCF and the VCA, I can't do so without using some form of external multiple. In this example, I'm simply trying to patch the standard configuration of a low-cost monosynth, but the µVentury II is not up to the task without external hardware. It's interesting to note that in the demo I saw, the µVentury II was patched using several inexpensive 'Y' jack connectors (where the output of one socket is split to two jack connections). At first sight, this may seem to be a simple workaround, but it can lead to further problems such as 'voltage droop', which can occur whenever a CV source is directed to multiple inputs that are, in effect, shorted together by the 'Y' connector. Let's face it... you shouldn't have to resort to such workarounds on a product of this price.

Apparently, Lassence will carry out custom modifications which can go some way to widening the restricted feature set. According to the manual, the following facilities and connections can be added: oscillator sync, a third modulation input, a clock output, and simultaneous variable-triangle-to-square, triangle, saw and sine outputs. However, these cost extra, and there is another problem — where would such sockets go? Lassence say they always find somewhere, depending on how many new features are to be added, but as the front panel is already pretty replete with socketry, it's difficult to see how they could do this without using the sides of the unit — and this would render the nice carry-case useless!

So perhaps we should look at the µVentury II in a different light. It's clear from their manual and web site that Lassence see it as more of a sound mangler and processor than a melodic synth, and they go so far as to liken it to vintage classics from Serge and Buchla. In doing so, they make a lot of Wave X, but (even ignoring the inability of the review model to modulate one of its own modules without recourse to external voltage processing) this is still no more creative or sonically interesting than, say, oscillator sync.

But what of the sound quality? To be honest, it's not bad. As I've already said, the quirks of the oscillators, such as the varying output levels, won't always be a problem depending on what you're trying to achieve, and the 12dB-per-octave filter, while lacking self-oscillation, sounds acceptable. Likewise, the envelope is reasonably quick, and the ring modulators do a good job. It's just a shame that you can't take advantage of this quality with better tracking, more modules and enough patching options to make conventional sound generation a reality. You can do a fair bit in the way of atonal effects creation, sonic mangling, filtering, and sweeping, and this will no doubt find favour with some producers and DJs, but again, I feel that if that's all the µVentury II can do well, it's limited.


I don't like finding faults with synthesizers. Music is my passion, and I want everything I own, play or review to be superb. But every once in a while, something comes along that promises much, and fails to deliver. I fear that the µVentury II is one such product, and that's a shame, because there are aspects of it that are good. The build, the component quality, the look and feel... all are worthy of praise. But unless you're wealthy enough to buy it for these alone, there are many more affordable products that do more, and better, and for less money.

So... I've mentioned it a couple of times, but let's consider the price issue in more detail. At somewhere around £1200 including shipping costs, the µVentury II is far from cheap. Allowing £200 for the case and power supply, this represents about £100 per function, which is a little expensive compared with most of the competition. Sure, it compares favourably with some of the other systems using quarter-inch sockets, and is certainly cheaper than a vintage Moog, but if the size of the sockets is not an issue, the current spate of 3.5mm systems are far more cost-effective. I tried assembling comparable systems (a pair of VCOs with LFO capabilities, a multi-mode filter, a couple of preamps, an envelope follower, a trigger generator, a contour generator, a VCA, a pair of ring modulators and a meter — all installed in a rackmount case) from the on-line price lists of several competitors, and was able to do this for less, or, at worst, something that cost about the same as the µVentury II. However, when this was the case, the modules in question offered numerous facilities not found on the µVentury II, including independently shaped VCO waveforms with waveshaping CVs, dual signal and CV inputs in the VCA, a pulse shaper and DC shifter in the trigger generator, a frequency-to-voltage converter on the envelope shaper modules, four-way multiples in the ring modulators... and so on. In fact, apart from the quarter-inch patching (which I always prefer to 3.5mm mini-jacks) and Wave X, the µVentury II offers nothing that you can't obtain cheaper elsewhere. And, if you compare the µVentury II to a virtual analogue... well, the comparison becomes silly.

So, does the µVentury II have a niche? When I first saw it, I was convinced that it had. I saw it as a potentially powerful synth effects unit for use where space is at a premium, or even for slinging around your neck to get into some serious knob twiddling in the clubs. It also seemed like an interesting addition to an exciting modular setup. Now, sadly, I'm not so sure.

infop.gif 1748.40 Euros (around £1150-£1200 at time of going to press).
Price includes VAT but excludes shipping costs from Belgium.
infot.gif Blue Bay +32 496 23 72 11.
Published May 2003