It's easier to be spontaneous when all you have to do is press a couple of buttons and go. From the mid-1970s until the early 90s, Oberheim was one of
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It's easier to be spontaneous when all you have to do is press a couple of buttons and go. From the mid-1970s until the early 90s, Oberheim was one of

It's easier to be spontaneous when all you have to do is press a couple of buttons and go.

From the mid-1970s until the early ’90s, Oberheim was one of the premier American synthesizer makers. Many hit records featured the sounds of the Xpander, the OB-8, the FVS-1 (popularly known as the Four-Voice), and other great Oberheim synths. Oberheim developed “The System,” which linked a synth, a digital sequencer, and a drum machine into a pre-MIDI network for electronic composition and performance.

The Oberheim name was passed from one owner to another beginning in the late ’80s; it eventually ended up with Gibson, the long-standing guitar manufacturer. More recently, Gibson licensed the name to Italian keyboard maker Viscount (rhymes with “pie count”) while still retaining ownership of the Oberheim brand. In addition to its own line of electric pianos and organs, Viscount made instruments for companies, including Gibson, with more familiar names for years. Under the name Oberheim Viscount Joint Venture, the company has released its first instrument, the OB-12 Z-Domain Synthesizer.

The OB-12 is an analog modeling synthesizer, but in the face of stiff competition, it's being touted as a unique digital instrument providing sounds you cannot get elsewhere. It certainly looks like a virtual analog synthesizer; the oscillators offer standard analog-type waveforms, and the front panel offers all the functionality of an analog synth. The OB-12 has a few other tricks up its sleeve, though, including a Phrase Recorder, a Motion Recorder, and Morphing. The Phrase Recorder is a MIDI note sequencer, and the Motion Recorder is a MIDI control message sequencer. Morphing is the ability to transition from one sound to another.

You can download updates to the OB-12's operating system, as well as its sounds and effects, from Viscount's Web site. Oberheim instruments are distributed in the United States by Armadillo Enterprises, which also distributes Clavia's Nord Lead synthesizers and ddrum percussion modules and pads.


The OB-12 is an all-digital synthesizer with 12-note polyphony and four-part multitimbrality that responds on four MIDI channels at the same time. Each voice has two oscillators, two LFOs, two multimode filters, and three envelope generators. In addition, reverb, delay, chorus, and overdrive are always available simultaneously.

Initially, the OB-12's bright blue color and profusion of front-panel controls are its most striking characteristics (see Fig. 1). The front panel has 87 buttons, 28 knobs, 25 sliders, and a data wheel (which the user manual calls the “rotary dynamic encoder”). Most buttons have LEDs either embedded in them or immediately above them. A numeric keypad lets you quickly enter parameter values or program changes. All those devices give the user tremendous real-time control of the OB-12's sounds. If all the front-panel controls aren't enough for you, inputs for two footpedals and two footswitches are on the back.

I really liked the large clear display; the 240-by-64-pixel backlit LCD is reversible, displaying either dark on light or light on dark. It displays the values of front-panel parameters whenever you change them and shows them graphically when appropriate. Program and Timbre names appear in type that's large enough to read from halfway across a room. Text can be entered in upper- and lowercase. Combined with all the front-panel graphics, the display makes it easy to find your way around.

The 49-note keyboard has an unweighted action. There are buttons to turn Velocity and Channel Aftertouch on and off, though I can't imagine why anyone would want to disable Velocity, except for some of the organ sounds. A ribbon controller to the left of the keyboard supplements the usual Pitch-Bend and Modulation wheels. The ribbon and foot controllers can duplicate the function of almost any front-panel control. Pressing the Hold button latches the ribbon's value. Pressing the Relative button defines the ribbon's center value as the first place you touch the ribbon.

Two pairs of outputs are on the back panel. Each of the four parts is assignable to the main stereo outputs, the auxiliary outputs, or any individual output. In addition, there's a stereo S/PDIF output, always a welcome feature on any digital musical instrument.

It also has jacks for two footpedals and two footswitches. Their functions are assignable per Program rather than globally, which might be a bit confusing if you expect the sustain pedal to always be a sustain pedal.


The primary mode for playing the OB-12 is the Program mode. Programs are made up of as many as four Parts, each Part containing one Timbre. A Program is what most synthesizer makers call a Performance or Multi, and a Timbre is what most call a Program. The OB-12 has 256 Programs and 256 Timbres available. They are all in nonvolatile RAM, so you can overwrite any or all of them.

In addition to assigning a Timbre to each Part, a Program specifies controller assignments, effects, equalization, arpeggiation, output busing, and other parameters. In the Part Settings page, you can determine the level of each Part, its transposition, and its keyboard zone.

You can also play in Timbre mode, but you lose control of some parameters found in Program mode. Within Timbre, you determine left-hand controller parameters, such as turning the Mod Wheel on and off, controlling the function of the ribbon controller and Aftertouch, and specifying the Pitch-Bend depth.

Because the Pitch-Bend depth is programmable at the Timbre level, each Part in a Program can react to the pitch bender differently. When you push the wheel, the pitch of one Part can go up an octave, another a third, and another a perfect fifth while the fourth Part stays the same pitch. This makes it possible to bend a note into a chord.


Oberheim's OB-12 is a Z-Domain synthesizer. The Z references time, whereas Z-Domain refers to morphing and the Motion Recorder. Those features hardly constitute a new form of synthesis, but because synth makers find it desirable for the technology in new instruments to be perceived as a fresh approach, “Z-Domain Synthesis” is what it's called. However, it appears to be indistinguishable from virtual analog synthesis.

The oscillators produce the standard pulse, sawtooth, and triangle waves, but Oscillator 1 offers more variable waveshapes. Its Wave Control knob, in addition to changing the width of pulse waves, changes the shape of sawtooth and triangle waves (see Fig. 2). Changing a triangle wave's Wrap simply adds harmonics, making the tone brighter. Making a change to a sawtooth wave's Spread detunes the wave with itself; the effect is like doubling the wave and shifting the frequency of the second version in relation to the first. At low settings adding Spread sounds like chorusing; at high settings it sounds like severe detuning. I was a little disappointed that although pulse width can be modulated with either LFO, Wrap and Spread can't. An FM knob in Oscillator 1 lets you modulate its frequency with a signal from Oscillator 2.

Oscillator 2 has a knob for changing only the pulse width. There are also coarse and fine-tuning knobs for shifting the pitch up to two octaves above or below Oscillator 1, as well as a button to enable keyboard tracking. Like the second oscillator on a true analog synthesizer, it can sync to Oscillator 1.

The Oscillator Common section is the OB-12's version of the mixer. Rather than individual sliders for each oscillator, the ring modulator, and the noise generator, the OB-12's three sliders are balance controls. One controls the balance between Oscillators 1 and 2, with equal gain in the center position. The second slider balances the ring modulator with the oscillators, and the third slider balances the noise generator with the oscillators and ring modulator. I don't understand why the OB-12's designers chose this design; a more traditional setup would require only one more slider.

Two resonant filters provide lowpass, highpass, and bandpass filtering. At the highest resonance settings, they fall just short of self-oscillation. The filters can be configured in series and parallel; therefore, you effectively can change the cutoff slope by combining the filters. That feature adds a lot of flexibility. The filters also offer split routing, which lets you route one signal from the mixer to one filter, and another signal to the other filter.

Because there's only one set of knobs, the resonance and keyboard tracking parameters are identical for both filters. In the Edit Filters page, the cutoff frequency of the second filter can be offset in semitones relative to the first filter, from eight octaves lower to two octaves higher. Both filters also share an envelope generator and modulation routing.

At first glance, the envelope generators seem basic. ADSR generators modulate the filter and amplifier, and the pitch envelope lets you change attack and decay times. Dig a little deeper, though, and you'll find more. In the Advanced Envelope page — accessed from the Edit Filters or Edit Amplifier pages — you can control additional envelope stages (see Fig. 3). You can delay the onset of the attack stage, add a second decay stage, specify a breakpoint between the two decay stages, and specify the sustain time. If the sustain time is shorter than the length of time a key is pressed, the tone decays at the rate determined by that parameter. When you change any of the envelope parameters, a graphic of the envelope is displayed.


I was quite pleased to see that there are five equalization sliders on the front panel. They can be assigned to either the graphic or parametric equalizer at the touch of a button. Whenever you move an equalization slider, a graph of the EQ curve appears in the display (see Fig. 4).

Only one type of EQ can be used at a time. In graphic mode, the sliders control the boost or cut at five fixed frequencies. In parametric mode, the top and bottom sliders manipulate the gain of fixed high and low frequency bands; the three sliders in the middle control the center frequency, the boost or cut, and bandwidth of the middle band.

The effects selection — reverb, delay, chorus, and overdrive — is not spectacular, but it is a valuable element of the OB-12's sound. There are ten overdrive types and six kinds of reverb. The delay effect is straightforward, with no choice of delay types. You can, however, modulate the delay time, which results in some bizarre pitch-shifting effects. The chorus provides all the typical parameters, including depth, level, modulation rate, feedback level, and predelay.

The maximum reverb time is a whopping 24 seconds. Except for reverb, all time values are given in arbitrary numbers from 0 through 100, rather than in seconds and milliseconds. Delay times and modulation rates can sync to MIDI Clock.

Each of the four effects has a dedicated knob and button. Normally, the knobs control each effect's depth. Turning a knob also changes the display to show the edit page for each effect. When you press the Level/Parameter button, each knob controls the value of one parameter for each effect, giving you immediate real-time control. In the edit pages, you can select which parameter the knob affects.


Many of the OB-12's Programs depend on the Arpeggio function to make them interesting and useful. For the most part, the arpeggiator is quite basic. It has the usual up, down, up-down, and random patterns, called Modes. You can set the Range as much as three octaves higher than the original notes. Pressing the Hold button latches the arpeggio when you release the keys, as expected. In addition to a dedicated Tempo knob, there's a Tap Tempo button for manually entering tempo data. Velocity can be either fixed or as played.

Within a Program, the arpeggiator plays only the Parts you specify. A split key defines the point above which notes won't trigger arpeggiation. Above the split key, the other Parts can be played from the keyboard in the usual fashion.

Arpeggios are divided into two Types: regular and irregular. These are further divided into Families. Regular Families contain notes of equal duration, from quarter notes to 32nd notes, including triplets. There are seven irregular Families that contain a measure's worth of notes with different values, forming a rhythmic pattern. Four of the irregular Families are nicely syncopated, and the other three are pretty unusual.

I expected the display's musical staff to reflect every change I made when editing the arpeggio parameters. Instead, it only changes when you switch from one Mode or Type to another. Because it doesn't indicate changes in Family, the pattern you see in the display may be different from what you hear (see Fig. 5).


The Phrase Recorder is the OB-12's note sequencer. It records and plays as many as four different Sets, each containing as many as 49 Phrases. Each Program can gain access to any Set. The maximum length of any Phrase is 32 measures. The Phrase Recorder stores as many as 16,000 notes, and sequences can be transmitted to external instruments through MIDI.

You can specify any key to trigger playback. The Phrase plays in a loop as long as you hold down that key. If the Hold function is turned on, the Phrase plays until you shut it off. As a sequence plays, you can vary the front-panel controls to change sound parameters. The Phrase Recorder is disabled when the arpeggiator is active, and vice versa.

A Phrase can be assigned to play any or all of the Parts in each Program. If a Part is assigned to the Phrase Recorder, it can't be played from the keyboard while a Phrase is playing. Otherwise, you can play the keyboard normally as long as you avoid the keys that trigger sequence playback.

Before recording a Phrase, you can choose its Set, trigger note, length, tempo, time signature, and other essential parameters. By enabling the Overdub feature, you can record multiple passes and add more notes as desired. Because there are no tracks in a Phrase, you can't assign notes to individual Parts, so it's not multitimbral.

After recording a sequence, you can use the Phrase Event Editor to make changes. This presents an event list that displays the location, pitch, MIDI Velocity, and duration of each note. You can either play the keyboard or use the front-panel controls to change pitch and Velocity. Location and duration must be entered numerically.


The Motion Recorder memorizes any buttons you push, knobs you twist, and sliders you move in real time. These are recorded into one of two sequence loops that play back at the touch of a button. When you play back a motion loop as you're playing the keyboard, a phrase sequence, or the arpeggiator, it sounds as if you're manipulating the front-panel controls as part of your performance.

Unfortunately, when you stop or disable motion playback, the controls don't return to their original values; they freeze at their current values wherever they happen to stop. A loop can be as long as 32 measures. If you don't want the motion sequence to repeat, you have to stop it before the loop is complete. I'd like to see an option to have it play once without repeating.

As the Motion Recorder is recording, you can change filter settings, oscillator waveforms, effects parameters — in fact, any of the front-panel settings. Only changes to the front-panel controls are recorded, however, and not the left-hand controllers. By enabling the Overdub feature, you can even record multiple passes and add more layers of control messages from the front panel, just like sequencing with the Phrase Recorder.

When you've finished recording, you can view an event list of the recorded changes. In the Motion Event Editor, you can change the value, location in time, and type of individual events. Because editing every event in this list can be tedious, it's often easier to begin a new sequence. Without an Undo function, you have to discard your work every time you mess up an overdub.

Is the Motion Recorder necessary? All the knobs and sliders send either Control Change or SysEx messages, so why not record and play back these changes on a “normal” sequencer? Unless you're dealing with many simultaneous parameter changes, you could even change them in real time with footpedals and switches. But if simultaneous parameter changes are going on, some sort of sequencer is essential. Why would anyone prefer a specialized sequencer for recording control messages?

What the Motion Recorder provides is immediacy. It's easier to be spontaneous when all you have to do is press a couple of buttons and go. The Motion Recorder is always at your fingertips; you don't have to boot up a computer or switch your synth out of Performance mode. Specialization equals convenience, and anything that speeds up the process of creating electronic music is worthwhile. Technology should help you rather than stand in your way. Of course, whether you find the Motion Recorder convenient depends on how you work — you may find it utterly worthless.


One of the features that puts the Z in Z-Domain Synthesis is its ability to morph one Timbre or Program into another. At the Program level, you can morph as many as four Timbres into four different Timbres. Morphing can be performed manually, using the Mod Wheel or a footpedal, or it can be performed automatically during a specified period of time or number of measures. If an edit page is displayed, you can watch the values change as the morph progresses.

Ideally, morphing should be a gradual transition from one Timbre or Program to another. The problem is that some parameters are switched rather than continuously variable. When switched parameters morph from on to off, for example, the change is quite abrupt. That change occurs at the onset of the morph.

I've discovered that morphing works well with sounds designed with morphing in mind. For best results, create two identical Timbres and then alter them to reflect how you want the morph to begin and end. Avoid switched parameters and sweeping changes that result in bizarre artifacts. Successful morphing requires trial and error, but satisfactory results are possible.


The OB-12's weakest aspect is its programming. Most of the onboard Programs and Timbres just can't rival the OB-12's competitors. There's some good material, but you have to weed through too many Programs that don't appear useful either in a musical context or for sound design. Virtually all the sounds that emulate acoustic instruments are weak. With some hotshot programmers, Viscount could soup up its sounds and make the most of the OB-12's capabilities. As my elementary school teachers used to say, the OB-12 is simply not living up to potential.

I don't mean to suggest that all of the sounds are awful. Some of the best are Minimoog emulations such as Solo Synth, except that it doesn't make any use of the Mod Wheel unless you do some editing. Crystal PPG is a cool, shimmering bell-like selection. The Program 12 Species brings back memories of Forbidden Planet sci-fi noises I made when I was a child. HyperActive is a clicky, hissy sound that I've never heard from another synth. Fooling around with its parameters yields some interesting results. Aryhthmic, despite Viscount's misspelling, makes good use of the arpeggiator's ability to play unusual rhythms. Astronomy sounds as though it might be appropriate in a planetarium.

OB Strings is a slow, atmospheric pad that makes a wonderful underpinning for other instrumental tones; it's one of the OB-12's most musical Programs. As good as it is, nothing is assigned to the Mod Wheel, which gives the impression that the programming is simply incomplete.

A surprising number of sounds don't use the Modulation Wheel at all, and quite a few don't assign Pitch Bend or any other left-hand controllers. When I powered up the OB-12 for the first time, I couldn't get the Pitch Bend, Mod Wheel, or ribbon controller to work with Program A-001, called OB Fat Pad. I soon discovered that controllers are programmed at the individual Timbre level, and the Fat Pad Timbre doesn't have any of those controllers assigned to it. It seems that Viscount would want the first sound to show off the OB-12's capabilities, but it appears that no one thought of that.

I don't understand why many of these Programs exist except to fill space. Many of them aren't useful, aren't pleasing to the ear (even if you're looking for rude sounds), and aren't even cleverly programmed. Bass & Strng sounds as though someone new to synthesizer programming created it. The two halves of Bass+Piano sound like neither bass nor piano. Atmosphere is anything but atmospheric. Funked Up is not funky at all unless you mean it in a negative sense. The percussion sounds, such as SY Timpani and Analog Kit, are disappointing. A lot of programs have humorous names like Drunken Fly and Smelly Cats, but they don't sound as comical as some of the supposedly serious sounds.

In the right hands, this could have been a cool-sounding synthesizer. Unfortunately, it fell into the wrong hands. With only 256 locations for Programs, all the locations should be filled. The last six Programs in memory, named Test, are essentially blank, reinforcing the notion that the OB-12 is a work in progress.


The operating manual is a little difficult to read at times. It's divided into two languages: the first half is Italian, followed by a translation in English. The translation, for the most part, isn't very good. For example, an overview of the OB-12's architecture is given in a section titled, “How to Be OB-12 Is Organised.” A lot of British terms and spellings crop up, such as calling a quarter note a “crotchet.” Considering that this instrument is being marketed to Americans, it would have helped to hire an American editor to read through the manual and fix translation problems.

OB-12 Specifications

Keyboard49-note unweighted; Velocity- and Pressure-sensitivePolyphony12 notesMultitimbral Parts4Sound Engineanalog synthesis modelingROM/RAM Programs0/256ROM/RAM Timbres0/256Removable StoragenoneSequencersPhrase Recorder, Motion RecorderEffectsreverb, delay, chorus, overdriveEqualization5-band graphic, 3-band semiparametricAnalog Audio Outputs(4) ¼" TS unbalanced; (1) ¼" stereo headphoneDigital Audio OutputRCA S/PDIF at 44.1 kHz and 16-bit resolutionAdditional PortsMIDI In, Out, Thru; (2) ¼" TS footswitch; (2) ¼" TS continuous footpedalDisplay240 × 64-pixel backlit LCD, reversibleDimensions36" (L) × 3.5" (H) × 15" (D)Weight37 lbs.

The manual lacks an index, and the table of contents isn't always detailed enough to help you find what you need quickly. Most of the time, however, the operating system is straightforward enough that it's difficult to get lost.

There's no documentation other than the manual. A list of the Programs and Timbres would be helpful. Considering that these banks are subject to change, such a list should at least be available on the Web site where you download the new banks, but it isn't.


I've owned a number of Oberheim synthesizers in the past, including a Two-Voice, a Four-Voice, an OB-1, and a Matrix-12. Sorry, Viscount, but the OB-12 neither looks, sounds, nor feels like an Oberheim. Overall, it sounds more like an Oberheim than, say, a Moog, but it will never replace either. Like the tone of a classic analog Oberheim, the sound is smooth and warm rather than searing or punchy. The OB-12 can probably come closer to re-creating the sounds of a classic Oberheim than the other way around.

I had hoped the OB-12 would be a modernization of the Matrix-12, but it falls short in several areas. The Matrix-12 could send and receive on 12 MIDI channels at once, and its flexibility with modulation routing was staggering. On the other hand, the Matrix-12 stored only 100 Programs and 100 Multis, and it had no graphic parameter display, no effects processing, no arpeggiator, and no sequencer.


If the OB-12 is your primary instrument, its unique sound might help you get noticed. If you already have enough synthesizers to cover all the other bases, adding an OB-12 to your arsenal will broaden your timbral palette. If you're adept at synthesizer programming, the OB-12 offers a nice toolbox for crafting new sounds.

Lackluster factory programs aside, the OB-12 looks and sounds good but not great. If Viscount would hire some talented programmers to develop enough dynamite patches, it might have a winner on its hands. But the present incarnation of the OB-12 just doesn't have any great hafta-have-’em, can't-live-without-’em sounds.

If you want to check out an OB-12 in a music store, listen to as many sounds as possible. Pick out the sounds you like and play with them for a while. Don't form your opinion based on what you hear when you first turn it on. The OB-12 doesn't have a demo sequence, so ask a salesperson who has spent some time with it to show you the ropes. You'll know if it's the right instrument for you.

Geary Yelton has been programming and playing synthesizers since the early 1970s. He still owns an Oberheim TVS-1 he bought in 1979.