Far from being a cut‑down version of one of its bigger siblings, the TEO‑5 is a brand new Oberheim synth with a personality of its own.
Back in the not so dim and distant past, the engineers at Sequential took one of the company’s synthesizers — the Prophet 6, to be precise — and whipped out all of its voice boards. But, realising that a mute synth is only slightly better than a deaf sound engineer, they then inserted a bunch of different voice boards based upon Oberheim’s legendary SEM module, made a few other changes, and revealed a new instrument that they called the Oberheim OB‑6. I reviewed this in 2016, and was impressed. I had liked the Prophet 6, but I liked this more.
Let’s now fast‑forward to the present, where you’ll find me noodling around with a new Oberheim synth called the TEO‑5. At the time of writing, it hasn’t been announced, but a quick glance suggests that Sequential have pulled the same trick here as they did eight years ago. Just look at the chassis and control panel; the TEO‑5 seems to have the same relationship with the Take 5 that the OB‑6 had with the Prophet 6. But appearances can be deceptive. While there are similarities, even to the extent that the draft manual contains accidental references to the earlier model, don’t be fooled into thinking that they are different incarnations of the same underlying five‑voice polysynth. Sequential have no doubt saved time and money by re‑employing some existing tooling, but the two are distinctly different instruments.
The Voicing
Like the Take 5, the TEO‑5 uses a pair of SSI2130 analogue oscillators for each voice, but that’s where the similarities in the audio path end. Whereas the earlier synth used SSI2140 filter chips, the TEO‑5 offers a version of the state‑variable 12dB/octave SEM filter per voice. Furthermore, there’s nothing on its motherboard that looks like a VCA stage, so I contacted the chaps at Sequential, and they confirmed a growing suspicion: unlike the Take 5, there are no audio signal VCAs; loudness shaping is performed in the digital realm. This was not what I had expected and it means that, unlike some other polysynths that I’ve reviewed in recent years, removing the digital effects from the TEO‑5’s signal path doesn’t give you an analogue synth.
Both oscillators in a voice offer three waveforms — triangle, ramp and variable‑width pulse — and you can select any combination of these that you wish. PWM is obtained independently for each oscillator from the modulation matrix (see box) and you can select one or more simultaneous sources to control this. Osc 1 also features a square‑wave sub‑oscillator one octave below the selected pitch. You can tune each oscillator over a range exceeding five octaves, although I found that — perhaps unsurprisingly — MIDI note C5 wasn’t exactly five octaves above C0 on any of the voices in the review unit, and remained a few cents out no matter how many times I calibrated the synth. You can also detune Osc 2 for the usual rich, chorused effects. As you would expect, the cross‑mod lacks the consistency of a digital FM synth, but you can use cross‑mod and sync simultaneously to create sounds that you might not expect from an instrument of this nature. You can disconnect each oscillator from the keyboard and MIDI to use as a drone or, in the case of Osc 2, as a static audio‑frequency modulation source. You can also set the portamento time independently for each. In addition, you can send the output from Osc 2 directly to the amplifier, bypassing the filter. This is an old CS‑80 trick that allows you to reinforce the fundamental after heavy filtering, but is more advanced in the TEO‑5.
You’ll find the source mixer in the filter section. This only offers on/off buttons for the oscillators, the sub‑oscillator and your choice of pink or white noise, but you can set the levels for each in the Program menu. There’s no external audio input. The SEM‑inspired filter itself has bags of character. This isn’t surprising, because a quick inspection suggests that it’s based on the OB‑X‑inspired filter in the OB‑X8. However, like its forebears, you can’t force it to oscillate, even if you use multiple modulators to increase the amount of resonance. (I tried.) If offers four filter types, smoothly transitioning from low‑pass to notch to high‑pass, with an additional band‑pass mode available from the Program menu. You can modulate the filter type, cutoff frequency and resonance using the matrix.
The rest of the signal path for each voice comprises an A‑D converter followed by four digital stages. The first of these is the digital amplifier that performs the role of the audio VCA in a pure analogue synth. Following this, the signal reaches the first of three digital effect units. This is a simple overdrive that — far from generating the unholy rasp obtained from some earlier generations of digital distortion — can add a pleasing body and drive to your sounds. This is followed by an Effect unit (great name!), which allows you to select one of 12 algorithms — four types of delay, chorus, flanging, an emulation of the classic Oberheim phaser, a high‑pass filter, distortion, an emulation of the original Oberheim ring modulator, rotary speaker and ‘lo‑fi’, the last of which combines overdrive and wow/flutter to emulate a sickly tape machine. There are only three parameters to control each of these, and you adjust them using knobs called Time, Depth/Mix and FBack/Misc. For the most part, these names are descriptive of their functions but, were I ever to use the TEO‑5 in anger, I would print the parameter chart, laminate it and stick it next to the synth. Finally, there’s a dedicated reverb with controls for the mix, room size, pre‑delay and decay time, and a multi‑mode HP/LP filter to shape the reverberated signal. Having reached the end of the signal path, the audio is then converted back into the analogue realm before being presented to the audio outputs on the rear panel.
Modulation & Shaping
The primary modulators in the TEO‑5 comprise the global LFO 1 and the per‑voice LFO 2. These generate the same range of five waveforms as each other, with variable slew to modify the wave shapes, plus controls for rate (reaching as high as 500Hz) and depth. Despite their seeming simplicity, their flexibility becomes apparent when you start to assign them in the matrix. You can even direct their outputs to their own inputs for all manner of uncommon modulation effects.
You can also create cyclic waveforms using the contour generators, of which there are two per voice. Used conventionally, these generate five‑stage (DADSR) bipolar contours with, by default, Env 1 directed to the filter cutoff frequency and Env 2 to the audio amplifier. Nonetheless there are two other routing options: Env 1 acting as an auxiliary contour generator assigned within the matrix and Env 2 controlling both the filter cutoff frequency and the amplifier gain; and Env 1 acting as an auxiliary contour generator and Env 2 controlling just the filter cutoff frequency while the audio amplifier is gated open when you press a key. (It’s harder to describe than it is to use.) Given that the contours are always available as matrix sources and can be assigned multiple times, the system is considerably more flexible than the control panel might suggest. Oh yes, and returning to the concept of using the contours as cyclic oscillators, you can program Env 1, Env 2 or both to repeat indefinitely and, with short attacks and decays, to generate audio‑frequency waves that you can use for things such as AM and FM synthesis. Both contour generators are velocity‑sensitive, and you can direct velocity to their amounts on the front panel, and to their times and sustain levels using the matrix. This is particularly useful for things such as the synthesis of plucked instruments.
More Goodies
Inevitably, the TEO‑5 offers much more than an audio signal path with a couple of digital LFOs and contour generators stuck on the side. For example, there’s a monophonic unison mode plus an associated chord mode invoked by holding a chord while pressing the Unison button. Since the TEO‑5 is responding monophonically in both these cases, it’s good to see that it provides low‑, high‑ and last‑note priority with either single‑ or multi‑triggering so that you can ask it to respond like your favourite monosynth. Then there’s the Vintage knob, which adds variation to the pitch, filter cutoff frequency and contour times on a voice‑by‑voice basis. Used gently, this can impart the usual, subtle inconsistencies that add interest to a sound. Interestingly, Vintage can be a modulation destination, so I created a simple lead patch, selected five‑voice unison with minimal detune, and then controlled the Vintage amount using the mod wheel. The results were great, allowing me to take a well‑behaved sound into new, thicker realms to accentuate the climax of a solo before pulling it back into line at the end. That’s worth some experimentation.
Low Split is another interesting facility. This allows you to select a split point on the TEO‑5’s keyboard but, rather than letting you place different sounds on either side (you can’t... the TEO‑5 is strictly monotimbral) it allows you to transpose the lower side of the split down by either one or two octaves. This increases the effective width of the keyboard to 4.5 or even 5.5 octaves, albeit with a one‑octave or two‑octave hole in the middle. If your music involves playing a bass note with your left hand and a triad or two with your right, I can see this being very useful. Happily, the correct MIDI note numbers are sent in both cases.
Talking of tuning, the TEO‑5 offers 64 memories for alternative scales, and you can save your selection from these within each Program. The choices range from subtle variations on conventional Western tuning, to Eastern scales, to some wildly experimental options, and the manual explains each of these in detail. It’s well worth experimenting with these even if you don’t expect your next Top 10 hit to exploit the subtleties of Helmholtz’s untempered 24‑notes‑per‑octave Harmonium Tuning.
In Use
When you look at the TEO‑5 from a player’s perspective, it’s apparent that it’s a new format for an Oberheim polysynth. All previous models sported either four‑octave keyboards (the 4‑Voice, 8‑Voice, OB‑SX, OB‑6 and — if you’ll allow it — the OB‑12) or five‑octave keyboards (the OB‑X, OB‑Xa, OB‑8, Matrix 6 and 12, and the OB‑8X). Only the mono‑ and duophonic synths (the OB‑1 and 2‑Voice) were narrower, and all 13 instruments had their performance controls to the left of the keyboard itself. Yet here we have a polysynth no wider than some monosynths, with its pitch‑bend and modulation wheels placed behind the keyboard. Why? I suspect that it’s because, when designing the Take 5 chassis, Sequential found that they could build (and therefore sell) a synth of this format more cheaply, broadening its appeal as an affordable option. This probably explains why the TEO‑5 also has plastic cheeks rather than wooden ones. Nonetheless, it feels very robust, and there’s not a wobbly knob to be found anywhere on it.
Happily, programming the TEO‑5 is easier than its wealth of functions might imply. Despite its diminutive size, its panel is clear and accessible with most of the controls being of the one‑function‑per‑knob or per‑button variety. Nonetheless, there are important facilities that can only be accessed via the matrix and the two menus. (The Program menu offers 33 parameters, some of which are already present on the panel, while the Global menu offers a further 34 that allow you to configure the TEO‑5 and tailor things such as the velocity and aftertouch responses to your taste.) Sure, the OLED is tiny, but this screen size has become the norm for many synths and rackmount modules in recent years and, as long as I had my reading glasses to hand, I found it to be clear and simple to use.
So now it was time to program and listen and, of course, ask the crucial question: “Does it sound like an Oberheim, or is it a generic polysynth painted with blue pinstripes in the hope that you’ll listen with your eyes?”. Rather than step through the factory sounds (that came later), I spent many hours creating sounds that might otherwise cause me to turn to one of my vintage Oberheims. I soon discovered that, while the filter in the TEO‑5 places it firmly in Oberheim territory, it’s not a miniature version of an OB‑Xa or OB‑8; nor is it a low‑cost version of the more recent OB‑6 or OB‑X8. In fact, the more I used it, the more I realised that it’s a new and enhanced Oberheim, not a slavish homage to the past, and that it has a strong character of its own. I programmed classic polybrass patches, synth strings, slow pads, chimes, percussion, effects, arpeggios, mini sequences and more and, while the TEO‑5 isn’t going to be your go‑to keyboard for things such as e‑pianos and organs, it proved to be remarkably flexible and it almost always sounded great.
I could have widdled all week with huge unison leads, sync‑leads, monster basses and more had I not had to take my hands off the keyboard to type this review.
It also turned out to be a fabulous monosynth. I created a simple two‑oscillator patch with two‑voice unison, maximum filter resonance and the filter cutoff frequency controlled by both contour generators to create a complex ‘blip’ and sweep. I then directed aftertouch to the LFO 1 amount as well as to the filter cutoff frequency and audio level, and added a slow chorus plus a touch of reverb. Whether used for bass duties or tweaked to grace a proggy magnum opus, the results were superb. To be honest, I could have widdled all week with huge unison leads, sync leads, monster basses and more had I not had to take my hands off the keyboard to type this review.
Of course, it’s fair to ask why Sequential implemented such an unusual signal path in the TEO‑5. There were probably several reasons, although the most obvious is that it’s cheaper to build a polysynth with digital LFOs, contour generators and amplifiers than with analogue ones. Another argument goes something like this... Depending upon various aspects of the design, the differences between an analogue oscillator and a modelled one can have an audible impact on some sounds. Likewise, the differences between an analogue filter and a modelled one. In contrast, the impact caused by replacing a VCA with a digital amplifier, and replacing analogue contours with digitally generated ones, may be far less apparent. Whether this is true depends on the nature of the design. If the digital amplifier is programmed to be linear and free of all noise and distortion it would, perhaps, replace the perceived ‘warmth’ imparted by an analogue VCA with digital ‘transparency’. But if the system is modelled to replicate the response of a given VCA and a specific analogue contour generator, replacing one technology with the other may make little difference. My experience with the TEO‑5 is that it’s a complete non‑issue; although I knew otherwise, nothing in its sound ever suggested to me that the primary audio path was anything other than analogue. Actually, that’s not quite true. The TEO‑5 is deliciously devoid of background noise and hiss. If that’s a consequence of the digital stages, sign me up as a fan!
Finally, I had to conduct a few functional tests, just to make sure that everything was doing what it should. I couldn’t check everything in the time available, but all seemed well and, while testing the MIDI and USB connectivity, I realised something rather excellent: there was no trace of the dreaded USB ground‑loop hum. That was the icing on the cake!
Conclusions
Before I played it, I must admit that I wasn’t particularly turned on by the TEO‑5, but that was a consequence of its narrow keyboard, the positions of its wheels, and the lack of either poly aftertouch or MPE. That mood evaporated as soon as I discovered how easy it is to program and how classy it sounds. Sure, if I were to use one as a polysynth, I would play it from a 76‑note controller and enjoy its sounds on a grander scale, but if your space is constrained, its size could be the attribute that allows you to use a genuine Oberheim where it may not otherwise be possible. There’s a great deal to like about the TEO‑5 and, now that it’s time to hand it back, I’m going to have to admit that I’m rather turned on by it.
The Modulation Matrix
Although the TEO‑5 appears to be a simple synth, its 19‑slot modulation matrix elevates it into complex sound‑design territory. The first 16 of these slots are freely assignable, drawing from a list of 19 sources (some global, some per‑voice) and 64 destinations. The other three slots are dedicated to the global LFO 1, the polyphonic LFO 2, and the auxiliary envelope. You can often select a source by holding the Source button and adjusting an appropriate control, and select a destination in the same fashion using the Destination button. Nonetheless, there are some options that you can access only through the menus. Interestingly, the amounts of each of the first 16 slots can be the destinations of the other slots, which means that you can create some unexpectedly convoluted modulation routings. What’s more, you can program multiple sources to affect a given destination and simultaneously direct a single source to multiple destinations. If you make full use of velocity, aftertouch, the wheels and the pedal inputs, the TEO‑5 proves to be a remarkably complex and expressive instrument despite its seeming simplicity.
Arpeggiators, Sequencers & Rhythms
The TEO‑5’s monophonic arpeggiator offers five modes, a maximum of three octaves’ range, up to three repeats per note, and Hold. I was pleased to find that the resulting arpeggios can be transmitted over MIDI so that you can drive other equipment in real time, or save interesting arpeggios on your DAW and direct them elsewhere if you decide to use a different synth in the future. The 64‑step sequencer is equally simple. It allows you to store up to five notes per step, and you can program ties and rests, but that’s all. There are no editing capabilities, so the only things that you can change are the playback tempo and the transposition. Happily, sequences are ‘per program’, so you can include one with every sound that you create. Like the arpeggiator, the sequencer can send its output to MIDI. If you have no hand available, you can control both the arpeggiator and the sequencer using a footpedal, which is always a good thing. The frequency of the internal clock that drives these ranges from 30bpm to 250bpm, with a wide range of clock divide ratios. You can also tap the cunningly named Tap Tempo button to determine the clock frequency, or replace it altogether with received MIDI Clock. As you might expect, the clock can also be used to synchronise the LFOs and delay effects, and you can invoke different ratios at each of its destinations to generate interesting rhythmic effects.
The Rear Panel
The TEO‑5 offers a simple rear panel. Starting on the left, you’ll find the digital I/O: USB for connection to your computer (no drivers needed for either Mac or PC), plus a full set of 5‑pin MIDI In, Out and Thru. Next come the two analogue control inputs: Footswitch, which is typically used for a sustain pedal but is also able to latch the arpeggiator and start/stop the sequencer, and an input for an assignable TRS expression pedal. Finally, there are the holes through which you hear the sound: unbalanced quarter‑inch left/right audio outputs plus quarter‑inch stereo headphones. (As always, I would have preferred the headphone output to be at the front of the synth.) More good news is the IEC mains socket that feeds the internal, universal power supply. There must have been a great temptation to use an external PSU on a synth of this size, and it’s to the designers’ great credit that they didn’t succumb to this.
Pros
- It’s a genuine Oberheim at a fraction of the cost of the OB‑X8 or OB‑6.
- It sounds excellent — in fact, it’s hard to obtain a naff sound from it.
- It’s far more powerful and flexible than is apparent.
- It feels solid and robust throughout.
- Despite being compact, it has an internal power supply (yippee!).
- Some people will find the narrow design convenient and a strong reason to consider buying it...
Cons
- ... although others will find the keyboard to be too narrow.
- Some players will dislike the positions of the performance wheels.
- Five voices will be too few for some uses.
Summary
The TEO‑5 is a lovely synth to program and, when you’ve done so, it sounds great. There’s much to recommend it and very little to criticise. Although its physical design will not be to everyone’s taste, it deserves to be a significant success.
Information
£1499 including VAT.
$1499.99
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