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Page 2: UDO Audio Super 6

Polyphonic Synthesizer By Rory Dow
Published December 2020


The approach to modulation is to offer hands‑on control where possible, backed up by a more in‑depth modulation matrix for more lesser‑used modulation routings. For example, when you want some simple vibrato, reach for the dedicated DDS LFO modulator slider. But if you want to control oscillator pitch from something a little more unusual, say aftertouch, then you can still do so by using the mod matrix. It works by using the same 16 buttons used for patch selection, eight buttons for sources and eight for destinations. Operation is easy: click one of each and adjust the Amount knob. Alternatively, you can also hold a source button, move a slider, and then adjust the Amount knob. It’s a clever way to keep the immediacy of classic analogue synth design whilst adding some modern flexibility. In the mod matrix, the available sources are LFO2, Envelope 1, DDS2, velocity, aftertouch, CV pedal and the pitchbend stick.

I love this implementation of mod matrix. It is very simple and fast to use, but it does come with a couple of downsides when compared with a typical mod matrix accessed with an LCD screen. Firstly, it’s not easy to see what modulation routings are already in a patch. The mod matrix buttons will illuminate to show you what mod sources and destinations are used, but because not all destinations are available on buttons you can’t always see all the modulations that might be active within a patch. The second downside is that not all modulation sources are available. I was particularly upset not to see LFO1 there, because its unique ability to create phase‑shifted left and right LFOs in Binaural mode would be an interesting match for destinations such as cross mod, or delay time. I asked UDO about this and they hinted that there might be some customisation options coming in the future that might allow this. Watch this space, as they say.

Everything seems carefully measured in order to prevent any unmusical outcomes. In fact, it’s very difficult to make the Super 6 sound bad.

LFO1 is the more flexible, whilst LFO2 is generally linked to the modulation wheel for vibrato or tremolo. LFO1 can achieve speeds of 0.05 to 50 Hz, or sync to internal or external clock. Triangle, square, sawtooth and random waveforms are available and you can even use any of DDS1’s 16 custom single‑cycle waveforms. Switch into HF (High Frequency) mode and the range changes from 20Hz to 20kHz. This opens up the possibility of using it as a third oscillator or for FM sounds. In this mode, you can choose to have static frequency, as chosen by the Rate slider, or have the LFO track the keyboard.

Possibly my favourite feature of LFO1 is the ability to alter the phase between left and right channels in Binaural mode. For example, by setting the Phase slider at 50 percent, the two channels will receive LFOs which are out of phase with each other. If routed to something like filter cutoff, this can lead to sounds that swirl dramatically around the stereo field. At lower values, it gives beautiful stereo widening without any obvious differences between the channels. Furthermore, the LFO can be set to delay, freewheel, reset on note‑on, or cycle through only once.

The second LFO is found to the left of the keyboard above the mod wheel stick. Like the first LFO, this one ranges from 0.05 to 50 Hz and can be set to fade in after a set time. Dedicated sliders route it to filter cutoff or oscillator pitch with switches to choose between mod wheel source amount, mod wheel and aftertouch or always on. This section also allows you to route the pitchbend to either oscillator pitch and filter cutoff.

The two envelopes are standard ADSR type. Envelope 1 has an additional Hold section before the Attack for delaying the onset, plus looping, invert and keytracking switches. Keytracking shortens the envelope stages the further up the keyboard you play in a manner similar to some acoustic instruments.

Round the back we find an IEC cable socket and on/off switch for power, USB type‑B connector for MIDI, MIDI In, Out and Thru on 5‑pin DIN sockets, continuous and sustain pedal inputs, a stereo audio input for routing signals through the filter and effects, left and right outputs and a stereo headphone socket.Round the back we find an IEC cable socket and on/off switch for power, USB type‑B connector for MIDI, MIDI In, Out and Thru on 5‑pin DIN sockets, continuous and sustain pedal inputs, a stereo audio input for routing signals through the filter and effects, left and right outputs and a stereo headphone socket.


UDO’s approach to effects is one I like: simple and high quality. The Super 6 boasts a delay and two chorus effects. The delay has just three parameters, level, time and feedback. It has a nice elastic BBD‑style time change so you can have fun tweaking the delay time. All three parameters can be modulated. The delay times range from 1ms to 1s and can be sync’ed to internal or external clock if desired.

The chorus is clearly modelled on the Juno‑6, with two buttons labelled I and II. These can be used individually or together to give three different strengths of chorus. I didn’t have a Juno‑6 handy to check, but they sound as rich and lovely as I remember the Juno chorus to be and, being stereo, they’re a beautiful match for the already spacious sound made by the synth engine.

Arpeggiator & Sequencer

The arpeggiator offers the usual suite of playback patterns, octave ranges and even swing amount. There’s a master tempo knob which offers a 30 to 300 bpm range or, with the external clock option enabled, the arp will sync to MIDI clock and the tempo control will adjust the playback speed in clock divisions. There’s a handy Hold function too, for hands‑off arpeggiation. Overall, a fairly bread‑and‑butter offering, but welcome nonetheless.

A 64‑step polyphonic sequencer is also available, although not at the same time as the arpeggiator. For each step you can program up to 12‑note chords, slides (ties), rests and accents (velocity). The length can be from one to 64 steps. Sequences can be manually started or triggered and transposed by the keyboard. Like the arp, the sequencer can clock to external MIDI clock, at which point the Tempo knob controls clock division.

With sequencer mode activated, the 16 patch buttons become 16 step buttons with four ‘pages’ used to access the full 64 steps. You can program sequences using classic step‑input, or you can program non‑linearly by using the step buttons. Rests, ties and accents are all entered the same way.

One of my favourite sequencer tricks is to set the sequence length to one step, enable Slide on that step, enter a chord, then transpose it using the keyboard. Hey presto: chord memory. With up to 12 voices and all of Super 6’s synthesis, rave stabs never sounded so huge!


If I had to sum up the Super 6 sound in one word, it would be ‘classy’. Everything seems carefully measured in order to prevent any unmusical outcomes. In fact, it’s very difficult to make the Super 6 sound bad. The sound is always sophisticated and elegant. Even the cross mod, which can sound dissonant and detuned, does so with an air of slickness. The Super 6 can sound huge, and fat, and create window‑rattling basses or piercing resonant leads, but it always has this classy sheen that makes everything sound like it’s already been ‘produced’. It wouldn’t necessarily be my first stop for raw analogue brashness, but that’s OK. Not every synth needs to be raw and ballsy. In the end, there is most certainly a ‘Super 6 sound’ and that’s a great thing.

The synthesis engine is intricate, and very flexible. I was able to coax out countless Juno‑esque pads, epic dance plucks, Vangelis leads, resonant techno arpeggios, Berlin school sequences, giant unison stabs, delicate electric pianos, IDM tape‑soaked basslines, rave chord‑memories and more, and I never felt like I’d exhausted the possibilities. It is a complex synth, but it rarely feels like one. There are very few hidden features and the decision not to include a screen almost always feels good. I think that’s a testament to good design. It feels simultaneously familiar, yet new and exciting.

As I said in the intro, the Super 6 is an ambitious synth for a brand‑new company, but I think UDO have pulled it off. They have managed to capture the immediacy and direct connection to the sound of the classic ’80s analogue polysynths like the Jupiter 6 and Juno 6, whilst simultaneously improving almost everything about them. The synthesis is more complex and flexible, and there are features that ’80s synth designers could only dream about. The star of the show has to be Binaural mode which, along with the buttery smooth DDS oscillators and the high‑class effects, helps to create a record‑ready sound. It’ll be interesting to see what UDO do next, but in the meantime the Super 6 might easily become a classic in its own right.

Voice Assign

The Super 6 can work in one of five different Voice modes:

  • Solo: mono, portamento always on, envelopes and LFOs always re‑trigger.
  • Legato: mono, portamento only on legato, envelopes and LFOs do not re‑trigger on legato.
  • Unison: mono, portamento only on legato, envelopes and LFOs do not re‑trigger.
  • Poly 1: default poly mode, successive notes of the same pitch can overlap.
  • Poly 2: alternative poly mode which chokes successive notes of the same pitch.

Binaural mode is always on for the three mono modes, and optional for the two poly modes. There were a couple of occasions where I would have liked a ‘Unison Solo’ mode, with portamento on every note, but in general, I think combining voice, portamento and re‑trigger options into presets in this way is very sensible.


The Super 6 takes a slightly different approach to unison by offering five different unison presets. There are no adjustable detune or pan controls.

  • Preset 1: three binaural voices are stacked and detuned.
  • Preset 2: six binaural voices are stacked and detuned (a little less than the previous preset).
  • Preset 3: six binaural voices are stacked in octave intervals.
  • Preset 4: six binaural voices are stacked in octaves and fifths.
  • Preset 5: six binaural voices are stacked as a major chord.

The unison modes can work in conjunction with DDS1’s Super mode, where the oscillator generates six additional unison voices (seven total), and Super mode does offer variable detune, unlike Unison. Enabling both DDS1 Super mode and Unison mode simultaneously can result in some truly enormous patches!

MPE (Nearly)

Support for MIDI Polyphonic Expression (MPE) is apparently coming to the Super 6. Unfortunately at the time of review, it was still to be implemented, along with a few other features such as NRPN support, MIDI patch dumps and MIDI over USB.

According to the manual, MPE mode should work in a simple way. The polyphonic expression of MPE, such as pitchbend and aftertouch, are assigned in the normal way using dedicated controls or the mod matrix. They simply become polyphonic when MPE is enabled. Polyphonic expression (CC74 in the MPE spec) is assigned through the Pedal/CV source in the mod matrix. Most patches should translate quite well from standard to MPE mode, but we’ll have to wait and see.


By starting up the Super 6 in a couple of special bootloader modes, the internal hard drive can be mounted on a computer desktop to give access to files. This provides an easy way to perform firmware updates, backup and replace presets or sequences and even replace the 16 custom single‑cycle waveforms used by DDS1. The waveforms are binary (raw data), two’s complement, 16‑bit integer, 4096 samples, so should be very easy to replace with your own as long as you have an audio editor that supports raw.


  • It looks and feels like a classic synth.
  • Binaural synthesis sounds great.
  • It’s really hands‑on.


  • The combined mod/pitch stick won’t appeal to everyone.
  • There are still a few features to add to the firmware.


Inspired by classic polysynths of the past, the Super 6 manages to combine nostalgia and a thirst for something new without compromising on quality, aesthetics or sound. Impressive stuff.