Studio Electronics Omega 8

Photo: Mike Cameron

In this ever-changing world of virtual analogues, modelled instruments, and software emulations, it's a pleasant surprise to find that some companies are making synths the old-fashioned way. But is nostalgia really what it used to be?

Tempus does indeed fugit, as I realised when I looked back at the preview of Studio Electronics' Omega 8 analogue rackmount synth, which I wrote for the March 2000 issue of Sound On Sound (see www.soundonsound.com/sos/mar00/articles/omega8.htm). I submitted the first draft of this in December 1999, which — as I write this — is over four and a half years ago. Has it really been that long? Since that time, Studio Electronics have produced a couple of revisions to the Omega's OS, bringing the long-awaited multitimbral mode to life in the process, and, more recently, they've switched UK distributors, resulting in a drop in UK price. Both of these factors justify us finally giving this full review to the synth.

You can be forgiven for not remembering what I said last time I had the Omega 8 in my studio, so I'll recap; I suggested that it had the potential to be a superb, if expensive, addition to anybody's studio. Since then, though, the gap between DSP-driven 'virtual-analogue' synths (VAs) and genuine analogue synths has narrowed considerably, and the latest VAs, both hardware and software, are now producing sounds that are indistinguishable from those generated by the real thing for most people. So, does the Omega 8 still have its place in the scheme of things? Let's find out...

Overview

I'll start with the basics. The Omega 8 is an eight-voice hybrid analogue/digital polysynth that offers two oscillators, a filter and an amplifier per voice. Sound shaping is provided by three contour generators, one of which you can assign to any three of 19 possible destinations. Modulation is supplied by two LFOs, again with a range of destinations. Niceties include oscillator sync, cross-mod, programmable glide, and an extensive MIDI implementation. There's also a Multi mode that offers a range of multitimbral facilities, plus individual signal outputs and inputs for each voice card that allow you to use the Omega 8 as a bank of individual monosynths, or as a set of limited signal processors. But the feature list is vintage synth-like in feel, by which I mean there are none of the bells and whistles we now associate with polyphonic synths: built-in multi-effects units, phrase recorders and the like.

All of this arrives in a 4U rack that offers 33 knobs, 35 illuminated buttons, and a small 16 x 2 LCD (for a head-on look at the front panel, check out page 208). Editing is a two-stage affair. You can effect simple changes by turning a knob, but detailed editing requires you to dip into each section's menus. However, twiddling a knob does not take the on-screen editing system to the appropriate menu, so you must select this by pressing one of the numerous 'Edit' buttons located across the panel.

Only one of the three knob-behaviour modes mentioned in the manual is currently implemented. This is 'Jump', which means that when you start to turn a knob, the associated parameter jumps to the value represented by the knob's current position. The manual suggests that Edit mode will turn the knobs into incremental controls, increasing or decreasing the parameter as you turn them clockwise or anticlockwise (respectively) irrespective of the current position, while Match mode will require you to move the knob 'through' the saved value before it affects the parameter. According to Studio Electronics, these modes will become active at the next OS revision, which is due soon.

Once in an edit page, you move around using the three cursor keys, and change values using the so-called Q knob. However, with no numeric keypad and no 'fast' mode, you can spend inordinate amounts of time twisting, and twisting, and twisting. Parameters can pass directly from 127 to 0, or from 0 to 127, which makes it quicker to move between extremes, but it's still slow. What's more, there's no comparison of the parameter's control-panel value and the saved one. Sure, there's a Compare function that compares the complete front-panel sound to whatever is in the current memory location, but there's nothing to allow you to compare individual parameters.

The Omega 8 offers full interfacing with each of its eight voices, providing inputs to and outputs from each of the voice boards, as well as the master stereo outputs. There's even a dedicted mono output.Photo: Mike Cameron

Internally, there are eight voice cards. These have dedicated stereo outputs that allow you to direct each voice to a separate destination, and with the pan position of your choice. These outputs are in addition to the stereo pair to which all voices are directed (but from which they can be defeated), and the mono output.

The filter on each voice card is a 12dB-per-octave Oberheim SEM-style device, but each card offers three expansion headers that accept piggyback filter boards. On a standard Omega 8, one of these headers (per board) is occupied by a 24dB-per-octave 'Moog-style' filter, while the other two are empty, awaiting the addition of further (optional) cards. As on their ATC1 monosynth, Studio Electronics offer two products to fill these slots; a filter based on the Roland TB303, and another based on the ARP 2600 (at the time of writing, however, it's unclear whether these options will be available in the UK — for more detail on the add-ons, see the 'Pricing & Options' box at the end of this review). There are two other boards in the machine: one that hosts a Motorola DSP, the operating system, the memory, and so forth; and the front-panel board that holds all the controls, the associated LEDs, and that diminutive display.

According to Studio Electronics, the Omega 8 is "the world's first completely programmable discrete analogue synthesizer". In fact, there are plenty of integrated circuits inside: every voice card boasts multiplexors, demultiplexors, microprocessor supervisors, quad op-amps, flip-flops, transistor arrays, amplifiers, and more. However, as far as I can tell, these are all part of the voice-control architecture, not the sound-generation system. The Omega 8's signal path is indeed analogue.

The Oscillators

Despite this, the tuning of the Omega 8's oscillators is controlled by a digital system that Studio Electronics call Accu-tune. The manual describes this as "a very accurate but not perfect software routine of computer-corrected oscillator tuning". Designed to retain some of the randomness of true analogue tuning and tracking, you can set Accu-tune to 'Off', 90-, 95-, 98- and 100-percent settings, but even at 100 percent there are inconsistencies from voice to voice. I have no problems with Accu-tune — after all, many vintage analogue synths have digital tuning mechanisms that hand pitch-control duties back to analogue circuitry once they have completed their routines.

Each oscillator offers three waveforms — triangle, sawtooth and variable pulse (10 percent to 90 percent) with pulse-width modulation. You can select any combination of these simultaneously, as well as the square wave sub-oscillator derived from Osc 1, and noise, if desired. Other facilities include oscillator sync, pitch sweep of Osc 2 by Env 1, and five 'modes' for Osc 2. These are called Normal, Half (which causes the oscillator to track at half-a-volt per octave), 'No CV' (which disconnects the oscillator from the keyboard CV), Low 1 (which lowers the normal pitch by one octave), and Low 2 (which lowers Half by two octaves). Unfortunately, the accuracy of the oscillators' frequency knobs is too low, and it can sometimes be next to impossible to land on the pitch you want, which is frustrating. However, you can dial in the pitches accurately using the on-screen menus. This is slightly more long-winded, but more accurate.

The Filters

The Omega 8 offers you one filter per voice, the nature of which you can select from a list of up to four voltage-controlled filters. As already noted, there are two types of filter available in the standard Omega 8: the multi-mode Oberheim SEM-style filter with low-pass, high-pass, band-pass and band-reject options, and a Moog-style 24dB-per-octave low-pass filter.

Three knobs are provided to control these, labelled Frequency, Resonance, and (keyboard) Tracking (from 0 to 100 percent). The Edit pages allow you to select the filter type used, with 'Aux 1' and 'Aux 2' options to access the optional filter cards. The only other parameter is 'Invt', which allows you to invert the effect on the filter of envelopes 1 and 3. However, this works on both contours simultaneously, so you cannot mix a positive contour with a negative one.

Setting up a basic patch and playing through the eight voices demonstrates that they sound markedly different to one another. A little investigation reveals that these differences lie in the filter cutoff frequencies, which — because Accu-tune corrects only the oscillators — are not the same for a given note, and do not track each other precisely across the keyboard. Setting the filter to self-resonance and Tracking to 100 percent revealed a spread of just under a semitone between the eight voice cards. This improved as the Omega 8 warmed up, but the filters never moved into tune with one another.

The manual states, "this is not wrong, or poor design", but I have many analogue synths whose filters self-oscillate and can be played in tune across the whole width of the keyboard. Whether this matters to you or not is a matter of taste, and of how you might wish to use the Omega 8.

While investigating this, I discovered something else about the digital control system within the Omega 8. If you set the filter to self-oscillation and adjust the cutoff frequency, you'll find that it steps, with divisions of about a semitone. Furthermore, I found a bug here. If the Transpose Octave is set to Low as you play the self-oscillating filter up and down the keyboard, you'll find that it stops tracking below MIDI note C1, irrespective of the setting for the initial filter frequency.

The stepping suggested to me that the control is quantised to seven bits, and Studio Electronics have confirmed that this is the case, but point out that control of the envelopes and LFO sweeps are 16-bit. Which brings us to...

The Envelopes and LFOs

As the previous paragraph suggests, the Omega's envelopes and LFOs are also calculated by the DSP. Thankfully, the envelopes are fairly snappy, way ahead of the sluggish digital envelopes found on some of the vintage synths that used this architecture.

Env 1 is hard-wired to the filter cutoff frequency, and Env 2 is hard-wired to the VCA gain. That leaves Env 3, which you can direct to any three of the destinations shown in the top table at the bottom of this page. There are dedicated knobs for Env 1 amount and Env 3 amount, but the control for Env 3 affects only the first destination. If you want to control the envelope depth for the second and third routings, you must do so via an edit page.

As you would expect, all three envelopes are velocity sensitive but, surprisingly, all three have an additional, knobless, but very important facility, entitled 'Decay 2'. When invoked, this determines the time it takes for (what would otherwise be) the Sustain Level to decay to zero after the initial Decay is completed. I seem to remember that this was the architecture of the Prophet T8, and the combination of Decay 2 and velocity sensitivity allows you to recreate the dynamics of hammered and plucked sounds with a realism that eludes ADSR contours.

The final option in this section is the ability to delay the onset of envelopes 1 and 3, with independent maximum delay times of 30 seconds or so. All in all, this means that the Omega 8 has two six-stage envelopes, and one five-stage envelope, which is pretty flexible.

There are two LFOs in the modulation section. Each offers a rate knob and a depth knob that controls the amplitude of modulation applied to the first of three possible destinations per LFO. The ubiquitous Edit buttons provide access to the detailed control. Page 1 allows you to specify the destinations and depths of the LFOs (see the table to the left for a full list) while page 2 provides control over the six waveforms, allows you to choose whether the LFO is monophonic or polyphonic (in other words, whether the modulation of all voices is synchronised or not), and whether the modulations are synchronised to incoming MIDI Clock. Happily, each of the LFOs can have its own MIDI sync setting, so you can, in effect, lock the two together, but at different rates. It's just a pity that you can't select LFO waveforms directly from a front-panel control, although I understand that the designers have had to make some tough decisions about what gets a knob on the panel, and what is relegated to an on-screen menu.

The third page is interesting, because this allows you to determine what Studio Electronics call the Key Trigger Modes and LFO Quantisation. The first of these is confusingly named... it allows you to choose whether the LFO is invoked in a random position within its cycle, or on the upward curve, or on the downward curve. The second quantises the LFO with a maximum spacing of two semitones spread over a sweep of a major ninth; eight steps playing the so-called 'strange' scale, plus an extra note. It would have been more musical had the LFO range been exactly 1V (ie. an octave), but there you go.

The final element in the modulation section is Xmod, or cross-mod (audio frequency modulation) of Osc 1 and/or the filter cutoff frequency by Osc 2. There's a button to select the destination, and a knob to select the modulation depth, the latter of which is also affected by Env 3 and the LFOs, if desired.

When I engaged Xmod and played a few notes, the voices had different timbres, and it was impossible to play them as a polyphonic patch. When one voice produced a pleasing FM timbre, the next might be a monstrous atonal blare. Whatever the cause, it means that FM is very much a monophonic tool. Studio Electronics claim that they've been unable to reproduce this degree of disparity from voice to voice when using Xmod except at very high mod-depth settings, but on the basis of the review unit's behaviour, I wouldn't personally recommend polyphonic use of Xmod.

Arpeggiator & Multi Mode

The arpeggiator is one of the least developed elements within the Omega 8, being monophonic, and having just three modes: Up, Down, and Random. Actually, make that just two modes — Random doesn't work! With a tempo knob, Start/Stop button, one- to four- octave range, and MIDI sync, it's not what you would call fully featured.

Multi mode wasn't working last time I played with the Omega 8, so I was looking forward to checking it out. Studio Electronics have changed the button presses you need to access it, which resulted in some delay (as of OS v2.2, the correct sequence is to press and hold Bank Part and the left cursor button; this is documented in the Read Me file accompanying OS 2.2 on the company's web site), but I got there in the end.

In brief, the Omega 8 has four different multitimbral modes. 'Prepared' mode allows you to set up a different sound for every voice, allocating bank, patch, octave and volume, and then plays them sequentially on a single MIDI channel. I'm not sure how you would use this mode, but I suppose that it might find favour if you wanted to step through sound effects.

The Omega 8 controls are clearly and attractively laid out, with well-delineated sections for the oscillators, filters, envelopes, modulation, patch programming, and multitimbral and MIDI operations. More options are accessible than is apparent from the front-panel controls, of course — plenty of other features are reached via the Edit buttons in each section and the two-line display.Photo: Mike Cameron

Next comes 'Split 1+7' mode. Experimentation revealed that this allows you to set up two sounds, again allocating bank, patch, octave and volume, but played either side of a single split on a single MIDI channel. As the name suggests, you get one voice below the user-defined split point, and seven above.

The third option is 'Layer 4+4', and this also does what it says; it allows you to allocate one patch to voices 1 to 4 and another to voices 5 to 8. Then, when you press the keys, it plays voices 1&5 together, followed by 2&6 (and so on) in sequence. Again, the parameters offered are bank, patch, octave and volume. Of course, this reduces the polyphony to four notes, but it allows you to create some huge sounds.

Finally, there's 'Multichan' mode. This differs from the others in that its associated parameters are bank, patch, number of voices and 'Type' (mono or poly). It is here that you configure the Omega 8 to act as anything from a single eight-voice polysynth to eight monosynths, or anything in between, subject of course to its limit of eight voices. However, you can't determine the MIDI channels completely freely. The Global channel 'N' controls the first part, 'N+1' drives the second, 'N+2' the third, and so on up to 'N+7', if such a number exists.

The Split and Layer modes worked fine, but I couldn't get multichannel mode to work properly — voices kept dropping out, and whenever I set up a new Multi of eight voices, it wouldn't play. Eventually, I found the help I was looking for near the bottom of the v2.2 OS Read Me file — a note there explains that in order to hear any edits or changes made to a Multi, you have to save it, load another one, and then reload your saved one. The Read Me also mentions the need for all eight voices to be assigned — if one or two aren't, the whole Multi doesn't work.

Even once I'd figured this out, I found some limitations while using Multi mode. In particular, while you can edit patches there, you can't save the changes. This is a shortcoming if you are setting up a complex sound, determining patch parameters while listening to the composite. Furthermore, if you use the arpeggiator in Multi mode, it cycles through the voices, rather than arpeggiating a single part, which would allow you to play on the other channels as it does so.

But on a more positive note, each part in a Multi can use a different filter type, so you can stack dissimilar sounds, or use the Omega 8 multitimbrally in ways that obscure the fact that a single synth is producing all the voices. This is a significant benefit.

MIDI

You access most of the Omega 8's MIDI functions using the dedicated button in the Multi/MIDI section of the panel. Pressing the button repeatedly cycles through six edit pages that allow you to define the synth's response to modulation wheel, velocity, pitch-bend, pressure (aftertouch), and two additional dual-destination controllers that are factory assigned as either mod-wheel, pressure or breath (controller 1), and dynamics or key tracking (controller 2). Strangely, these override the dedicated mod-wheel, pressure, breath, dynamics and key-tracking parameters set in the previous pages. So what's the point? Well, to be fair, there are times when you want to direct a single controller to two destinations so, while it's confusing, it does makes sense.

By and large, this is all good stuff, but there is a catch. If you send a non-zero velocity or non-zero modulation value to the synth and then change a controller's destination, the existing value remains in effect until you eliminate it manually. This can be very confusing if, for example, you are scrolling through MIDI parameters and destinations while playing, or with the mod wheel slightly offset. For a full list of the controller destinations, see the table at the bottom of this page.

The Omega 8 transmits the positions of the majority of its knobs and buttons as continuous MIDI controllers. There appear to be a handful of exceptions, such as oscillator sync on/off, but these are relatively minor omissions, so you can record and replay almost all of your tweaks if you wish. This means that you can sequence patch changes, editing and refining them in your computer as a stream of MIDI CCs. If you're into knob-tweaking as part of a performance, this can be a very powerful facility.

Processing External Signals

The rear of every voice board features a socket that allows you to insert external signals into a voice's signal path. Processing the external audio is simple. From Filter Edit page 2, you set the input level, the balance between the external signal and any sound generated by that voice (known as 'Mix'), and the trigger level and trigger window. These parameters aren't explained in the version of the manual I was using, but experimentation revealed that the trigger window appears to set an amplitude range that will generate a Gate, whereas the trigger level seems to be a threshold above which all amplitudes output a Gate.

The external signal passes through the voice's filter, and when it reaches the programmed trigger level (or range) it sends a Gate to that voice's envelope generators. Many owners will find uses for this, including the usual chopping up of existing audio using MIDI sequences and controllers.

Glide, Pan & Unison

The final set of facilities include an extensive Glide section that offers linear and exponential curves (nice), normal and legato modes, extensive destination options (all combinations of Osc 1, Osc 2 and the filter cutoff frequency) glissando, and even 'Auto Glide' which is the old 'Bend' found on some vintage synths. This can be upwards or downward, with user-programmable distance and speed, and is velocity-sensitive. Very nice.

There's also an extensive Pan page. This offers not only the pan position, but a panning LFO for each voice, with programmable rate and depth, a choice of panning waveforms, and optional MIDI Clock synchronisation.

Additional keyboard facilities include Unison (two, four, six or eight voices), voice allocation mode (first available or cycle), note priority (last/low), and multi-triggering on/off for any combination of the envelopes. Unison fattens the sound considerably, but it's worth noting that it is always monophonic, no matter how many voices are assigned to it.

Bugs & Omissions

I think that it's fair to say that this revision of the Omega 8 OS is close to being complete. But I've already touched upon the issue of bugs, and I found others during my time with the Omega that I've not yet mentioned.

For example, the manual admits that, when you change patches, the Omega 8 can lose a voice. This means that silence ensues when the lost voice is chosen by the voice-allocation system. The Multi mode also lost voices with alarming regularity, sometimes when I accessed the mode, and sometimes when I made an edit. In the early stages of my investigations, this may have been because I failed to reload the memories in the required manner, but I experienced problems throughout my couple of months with the Omega. There was also a volume bug in Multi mode; the output volume is always at maximum, even when the Master Volume control is at zero.

Other bugs were more intermittent. For example, I selected a patch with the volume of Osc 2 set to zero, and then increased the oscillator level. The oscillator appeared on voice 1, but none of the others. Switching the Osc 2 sawtooth and square buttons off and on again cured this. Then there were the numerous occasions when Accu-tune tuned a voice a semitone flat. A second application usually corrected this, but why was it wrong in the first place?

As far as omissions are concerned, I would have really liked a built-in means of backing up data, whether a cartridge slot, floppy drive, or ZIP. A headphone jack would also have been welcome — it seems odd to me that a synth of this price doesn't have one.

However, there are two omissions that I am glad to report. Firstly, between the preview model and today's instrument, the Omega 8 seems to have lost the ability to crash. Secondly, it no longer demands a new EPROM each time you upgrade the operating system; you can upload new OS and sound files using SysEx. While not perfect, this is a huge improvement over the previous method.

Sounds

Studio Electronics describe the sound of the Omega 8 in different ways, usually variations on 'obese', 'phat', 'warm', and 'squelchy', the implication being that it has the depth and sound of classic American polysynths such as the Prophet 5, Oberheim OBX, and Memorymoog. But this was not what I experienced while using it.

I programmed a range of voices during my couple of months with it, including impressive pads, brass, organs, leads, basses, and many of the other classic 'analogue' sounds that I enjoy. I found that there's also wide scope for experimentation and ample opportunity for extreme noises. I particularly liked some of the shimmering, other-worldly sounds that the Omega 8 can produce. But none of these patches sounded like a Prophet, Oberheim, or Moog to me. To my ears, the closest thing to the Omega 8 — in terms of look and feel, sound, features and, of course, being analogue — is the Roland MKS80, with a bit of the MKS70 thrown in for good measure.

And another comparison occurred to me. The Omega 8 has a clean signal path, and a full-bandwidth frequency response, both of which are good things. In contrast, the Prophets, Oberheims and Moogs of previous years sound fat partly as a result of noisier signal paths and somewhat limited bandwidths that concentrate their sounds in the low and mid frequencies.

So ask yourself; what sounds like a vintage-analogue synth, but also sounds clean, bright, and has full bandwidth? The answer is... a virtual analogue synth! If pushed for a comparison, I would say that the underlying character of the Omega 8 shares some of the qualities of the Roland MKS80 and some of a modern VA. Of course, we're talking about subtle distinctions here. Blindfold me and play a single note of (as near as possible) the same sound produced on an MKS80, a Supernova II and the Omega 8, and I would be hard-pressed to tell which was which.

You may hate this comparison, and I fear that Studio Electronics may, but I intend it as no insult. Whereas my Prophets, Oberheims and Moogs tend to be wrapped in plastic sheets and put into storage at the back of my studio for lengthy periods of time, the flexibility and transparency of my MKS80 has ensured that it has remained plugged into my desk throughout the past two decades.

But this leaves us with a problem. Modern virtual-analogue synths are much cheaper than the Omega 8, and are more flexible, especially in terms of voices, multitimbral options, and effects (56, for example, as opposed to none). So, perhaps the most obvious use for the Omega 8 is as a colony of discrete, dual-oscillator monosynths. Given the facilities provided by each voice, and the flexibility of the MIDI control over each, it's not unreasonable to divide the price by eight, and think of it as eight instruments, each costing around £500 or thereabouts. If you have a need for so many simultaneous monosynths, and can afford the extra filter cards needed to give them diverse characters, the Omega 8 could then be a cost-effective solution. But not as a cost-effective polysynth — unless, of course, you lust exclusively after analogue instruments like the Omega 8.

Consequently, I think that this synth is going to appeal most to wealthy musicians, as well as those who, although less likely to have the cash to buy one, don't like the sound of digital synths for whatever reason.

Epilogue

To be honest, I have some sympathy for Studio Electronics. That they are enthusiasts is clear. They love their synths, and what they stand for. Furthermore, once you have made allowances for shipping, import duty, dealer margins and VAT, £4000 is probably a fair price for a machine of this construction and complexity.

But 2004 is not 1983, and although you once had to pay £4000 (or more!) to obtain an eight-voice polysynth with no effects and limited multitimbrality, this is no longer the case. I think it's fair to say that anyone deciding on the basis of price alone will pass up the Omega 8 and its ilk for a more modern synth. But that doesn't mean there isn't a potential market for it. Just as some people continue to champion vinyl over CDs, others still champion analogue synthesis over digital — although I don't necessarily count myself among them. On that basis, I say good luck to them, and good luck to Studio Electronics. The Omega 8 is a noble effort, and one which — when its current problems are resolved — we should respect.