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Oberheim OB•12 v1.5

Analogue Modelling Synthesizer By Gordon Reid
Published April 2002

The Oberheim/Viscount OB•12 was already a well-specified virtual analogue synth when it was launched in 2000, but it failed to gain much of a following. Now, after an OS upgrade and a cut in price, it's seriously good value for money...

OBERHEIM OB12 keyboard synthesizer.We all find some things hard to comprehend, and whatever your personal list may be, I would like you to add the following to it. Why, when so few players have used one, do so many synthesists scorn the Oberheim OB•12? I'm referring not only to the apparently slow sales of the product (how many have you seen being used on stage, or even on Top Of The Pops?) but also to the almost complete lack of interest demonstrated by the various synth forums and chat-lines on the Internet.

I have a theory as to why this might be: we keyboard fanatics do not permit our icons to develop or change. Real prog-rock bands should never embrace pop, real R&B artists should never sing MOR ballads, and real analogue synth manufacturers should, never, ever embrace digital technology. So, for an organ manufacturer such as Viscount to own the rights to the Oberheim name, and then — in an act of the highest sacrilege — produce a DSP-driven 'virtual analogue' sporting that name... it doesn't bear thinking about. "Death to the impostor", I hear you say. This attitude is a real shame, as it means you miss out on all sorts of interesting developments, such as what's been happening to that particular DSP-driven virtual analogue since my original review of it in SOS.

Before proceeding, I suggest that you take a look back at that review (see SOS September 2000). If you do so, you'll find that I liked the instrument a lot. With greater programming depth than the similarly priced Korg MS2000, but at a fraction of the outlay you might expect to make for a Waldorf Q, Access Virus Keyboard or Novation Supernova II, it combined superb synthesis and excellent value. So, when I heard that Viscount were shipping the OB•12 with a revised version of the operating system, I was determined to see what improvements it might offer. That UK importer, Turnkey, had simultaneously cut the price to just £499... well, what keyboard player could fail to be excited?

When the revised OB•12 arrived, I started to burrow into its menus in anticipation of finding exciting new functions. However, try as I might, I couldn't at first find anything different. However, I hadn't played an OB•12 for nearly a year, so I put it down to a rusty memory and contacted Viscount's support group in Italy for further information. After a couple of weeks, I found out that Viscount had indeed completed a lot of work on the OB•12. However, unlike manufacturers who retail unfinished synths (thus making you, gentle reader, their guinea pigs and beta-testers) the company's programmers had been polishing the system, not filling in holes.

The Improvements

The first versions of the OB•12's digital oscillators exhibited a number of minor bugs. These manifested themselves as small spikes generated when, for example, you attempted to control the PWM parameter when the pulse width itself was already greater than 97. Other instances of these clicks might occur when a square LFO controlled the pitch (trills), or when you changed the sawtooth 'spread' parameter from '0' to '1'. There were other bugs, notably in the oscillator envelope, and in Oscillator 2 with keyboard tracking set to 'off', although none of these had caused me any problems last year. Anyway, they're irrelevant now because they're gone. Oh yes, and while they were at it, Viscount remapped the FM parameter to improve control of frequency-modulated sounds. Bravo.

Moving on to the filters, Viscount remapped the values of the frequency and resonance parameters, making them more useable and fixing another esoteric bug. Likewise, they eliminated an unwanted distortion that could creep into the signal. They then improved the response of the Boost/Cut control in the parametric EQ, improved the reverb level and chorus feedback, and removed some unwanted taps in the Delay.

In addition, the CPU operating system benefited from a number of upgrades. Some minor bugs in the display pages have gone, as has an esoteric memory error that prevented the correct saving of phrases and parameter control sequences under certain circumstances. There are six new NRPNs, which control the wave status of the oscillators. Viscount also claim 'improved' MIDI handling in various modes, and better data handling when you use the OB•12 with a PC editor. Finally, there's the single new command: Local Off.

OBERHEIM OB12 rear panel.

Putting It To The Test

As I'm sure you'll agree having perused this information, some of the recent improvements are subtle to the point of being undetectable in normal use. However, there were a number of more obvious problems in the first OB•12 I reviewed, so I was curious to test whether these faults still manifested themselves.

I started with the tremolo bug in LFO 2. To quote myself, "If you apply the LFO 2 triangle waveform to the amplifier to create tremolo, it exhibits a little hiccup between cycles". Happily, that's no longer a problem.

I described a more annoying bug as follows: "... the OB•12 seems unable to handle four-note chords in Unison mode, playing some notes instantaneously, while others follow a fraction of second later." Unfortunately, this proves still to be the case, reaffirming my suspicion that the OB•12 lacks sufficient DSP power for some of its tasks.

My next complaint was that passing a Timbre through the overdrive made it revert to mono. Again, this is still the case. Unless this is another DSP power issue, I can see no reason why it should be so, and I hope that Viscount will address the problem soon.

I noted another fault as follows, and sadly this one has survived in a lesser form: "you have to be careful not to overdrive the filter input at maximum resonance. The result is digital distortion". This is now serious only when noise is the signal source, so it's unlikely that you will find it to be much of a problem. Nonetheless, it's a shame it wasn't fixed completely.

On the brighter side, the Phrase Recorder now understands Splits. Secondly, the Event Editor no longer exhibits the nasty bug I grumbled about in my original review, whereby if you edited notes close to 1:1:00, the closest they got to this value was an offset equal to their durations. If you intend to use the Phrase Recorder, these are not minor improvements!


I find Viscount's approach to their OS revisions extremely interesting, because the recent upgrades have either fixed minor bugs, or improved the operation of existing facilities. This is in marked contrast to the approach taken by manufacturers who launch unfinished instruments, and then use software revisions to upgrade the products already sold to end users.

So where does that leave the OB•12? It's clearly a mature product, displaying remarkable stability, very few glitches, and no crashes. On the other hand, there are still a few bugs to be swatted, and one or two that may be incurable given the existing hardware. But for me, the decisive factor is the price. At just £499, the OB•12 is a bargain. What's more, it remains a doddle to program and use, and it provides an excellent alternative or complement to fatter, more 'American-sounding' competitors, such as the Virus or Supernova. It's probably not an ideal first (or only) synth, but at this price, I just might buy one myself.


  • An improved operating system with numerous minor bugs eliminated.
  • A couple of useful additions in the CPU and MIDI software systems...
  • ...and all at a very competitive price.


  • A few bugs have survived the upgrade.
  • The DSP may still be under-powered for use in Unison mode.


The OB•12 remains a misunderstood instrument, but it offers almost glitch-free operation, is easy to use, and satisfies the need for an alternative to more conventional-sounding 'virtual analogue' synths. And at its new price, it's great value.


£499 including VAT.

test spec

  • OB•12 OS v1.5