Oldies but Goodies: Audjoo’s Helix


The Helix synth, released by by Audjoo in 2008, is an Oldie-But-Goodie synth plugin with huge sonic possibilities.  Read here why it is an instrument still worth your attention.


By Rob Mitchell, Mar. 2015


Helix was originally released by Audjoo in 2008 after being in a beta period of about one year. Over the years, Helix has been updated in various ways. In 2009, a Rompler oscillator was added, while later that same year they released an AU (Audio Unit) version. When 2011 rolled around, Audjoo added more presets, additional LFOs, 100+ new cycles (waveforms) for the Wave oscillator, plus other fixes and improvements. For 2013, Audjoo added better support for 64-bit hosts, separate 32-bit and 64-bit versions for Windows, some more fixes, and an improved demo version.


Even though it has been around for a while now, I thought I’d bring some attention back to this gem for this issue of SoundBytes since it was recently reduced in price. Actually it was greatly reduced, and it is now only $75 USD. It was originally selling for $145 USD.  

I’ll have to admit, I didn’t know about this synth plugin until a few weeks ago. When I read about some details of Helix, it seemed to have lots of possibilities, and I just knew I had to check it out. After hearing some audio examples made with it, that was it for me. This synth plugin really sounded great, and so I set out to cover it for this review.

I’ll quickly cover some of its many features: It includes five different oscillator types, three filters (with seventeen filter types), a monster matrix section, an arpeggiator, and many effects. If that’s not enough to get your attention, then read on, as I go into more detail.

The system requirements for Helix are easy to take.  It will work in 32-bit and 64-bit DAWs that support the VST or AU formats. Audjoo recommends at least a 1 Ghz CPU, and one gigabyte (or more) of RAM. The manual doesn’t state which operating systems it will work with, but I used it on my PC with Windows 7, and it worked just fine.

The installation was easy. After opening the self-extracting file, it creates a folder with nearly all the files needed. The only other file you’ll need to deal with is the license file, and you just have to place that into the “audjoo helix data” folder.



Helix includes four oscillators, and they are separated by two different tabs. To enable an oscillator, you click on a small button in the upper-left area of that particular oscillator. It won’t show any controls on the screen if it isn’t enabled. 

Each oscillator has a “Stage” setting. This lets you set its routing to one of six different stages. Each one is either a filter or shaper. I will get into more detail on those later.

There are five different oscillator types to choose from: Wave, Noise, Analog, String, and Rompler. Some of the controls change depending on which oscillator type you choose. When you set it to Wave, you have some of the usual controls you’d expect, as well as many others. For example, besides the standard octave, semitone, detuning, and panning, there is a “mask” setting. This lets you assign a keyboard range to that oscillator. You could set up each of the four oscillators to only play in a certain range of keys.

I won’t go over every single control in Helix, but some of the other controls in the oscillator section are the Amp (bi-polar volume), Phase, Pan, and Unstable. The Unstable control has adjustments which let you add an amount of instability to the pitch of the oscillator. One other useful control is the main slider bar in the middle of the screen. If you click on something you want to adjust, you can then use that slider to change its value. Some of the controls in Helix are easier to adjust than others, but I quickly got into the habit of using the larger slider to make most of my adjustments. It’s a lot easier to make fine adjustments to your settings.

Over to the right of the main oscillator controls you’ll find the “Multi” and “Waveshaping” sections. In the “Multi” section, you can have up to sixteen waves on top of one another. Also in this area are Spread, Phase, Width and Free controls. The Spread control will slightly detune each voice, and works well for fattening up the sound. The Phase control will adjust the starting phase for each voice, and changing the Width will affect the stereo placement of the voices. The “Free” control basically does what Phase can accomplish. The Free control has a lot less of that so-called “phaser effect” when it is being used as compared to the Phase control.

In the Waveshaping section, you are able to load in one of the many included waveforms, and change its sound to your liking. It is a bit like sculpting audio, and you shape and mold the sound the way you want. After you load a waveform, (or use the init preset with its saw wave) there will be two versions of that waveform that you just loaded (A and B).

Each of them can be manipulated with the large number of controls. Some of these include Mirror, Warp, and Bit, just to name a few. These let you play with the shape of the waveform itself, and will affect the frequencies you hear. Once you have changed the waveforms to the way you’d like, you can use the Morph function to blend between A and B. This could be automatically morphed using an LFO, envelope, or whatever else you’d like from within the Matrix.

When you switch to the String oscillator type, it will emulate the sound of two strings vibrating. The controls that appear after selecting this oscillator type include Frequency Spread (detuning), Low Pass, Damp (muting amount), Morph (pick position), and Cross Talk (one string gets some vibration from the other). The String oscillator sounds great, and has a nicely modelled sound.

The Noise, Analog and Rompler oscillator types are much simpler to use. With the Noise type, there is just one button you use to select either mono or stereo noise. The Analog type is really a square wave, and you can adjust its pulse width. The Rompler oscillator type lets you load in .sfz files, and there are 15 included to get you started.



In the oscillator section of this review, I mentioned “each oscillator has a Stage setting.” This means that for each oscillator, you can direct its output to one the six stages. The Stages section itself is made up three filters and three shaper modules. This is a powerful section in Helix, it being semi-modular. In its simplest form, you have each filter and shaper enabled with one right after the other. For example, if it is set for the signal to go from A to B, then to C, and then to D (and so on), it is in a basic series mode. You could also set it up in a parallel mode, with A and B plus C and D in parallel, and then going on to be mixed and finally getting to E, and then F. You don’t have to use all of the stages, as each of them can be turned on or off.

The filter settings have all kinds of options available. If you set it to Standard, you can then pick from Low Pass, Band Pass, or High Pass filter types. They have the famous Ladder filter type as well, and it has up to four poles to adjust the slope.

Besides the regular filter types, they have options added to let you switch the filter stage to some alternate modes. These include a limiter, EQ, delay, string, and an oscillator mode.  


Effects and Global Settings

To get to the effects in Helix, you just click the FX tab. It is located just to the right of the Stages tab. This is also where you can get to some Global settings.

There are seven different effects available, including distortion, chorus/flanger, phaser, delay, reverb, limiter, and EQ. They can be dragged and dropped in whichever order you want.

Some of the Global settings are the Master volume, Glide settings, and Polyphony mode. One of the choices of the Polyphony mode is an Arp setting, which includes 14 different playback modes (many use arp-script text files), and it can be synced to the host time.


Envelopes, LFOs, and Sequencer

Helix has a large number of envelopes included. There are a total of eight of them, and EG1 is hardwired to the amplitude. You can still map EG1 to other targets in the matrix, just like you can with the seven other envelopes.

Each envelope has a graphic representation of its ADSR shape, and I think this is always beneficial. The visual feedback definitely makes it easier to design presets. The levels of the envelopes are bipolar, and each stage of the envelope has a shape setting. In addition to the usual ADSR controls, there is one other control called R2, and it is for adjusting the secondary release time. You have your choice of Linear, Smooth, Exponential, and Late settings for all of the curves. Along the right side of each envelope are slider controls for Attack, Decay, and Level Velocity Sensitivity.

LFOs are in no short supply in Helix, as there are four polyphonic LFOs, and as well as four additional global monophonic LFOs. They each have eighteen shape settings, which include many standard waveforms such as Sine, Triangle, Square, Saw. They’ve also added many useful types of step-sequenced settings to choose from. The four main LFOs also include controls for Hold, Attack, Release time, and Release Target slider controls. In addition, you can set them as free running, and you are able to sync to the host tempo.

There are two sixteen-stage Sequencers available, and the slider controls for each stage are bipolar. They can be synced to the host, or you can dial in a speed using the Period control. There is nothing built-in to the Sequencer sections to assign actual notes or other values for modulation. This is all done inside the modulation matrix.

You can use the slider to change a step’s amount, and if you have SEQ1 mapped to Pitch in the matrix for instance, it will play a note according to how you set that slider. The manual describes a way to map certain pitches by using the matrix, but it’s a bit cumbersome. You can also adjust how many steps are used by setting the start and end loop values. The Lag control adjusts the amount of glide between the steps you’ve setup.


Modulation Matrix

The tab for the Matrix is on the right side of the OSC 3+4 tab. After clicking on it, it opens up the page for the Matrix. It has 36 rows available, each with a source and destination (Dest1), as well as a second destination (Dest2) and a Scale field.  A source can be something such as an envelope, or an LFO. A destination might be something like the oscillator pitch, or filter cutoff.

In-between the source and destination is an amount slider. It lets you adjust how much the destination is affected by the source. It can have a positive or negative value. For the second destination, you could select another target that you want to have affected by the source. Maybe you’d like the first destination to be the oscillator’s pitch, while the second can be directed to the oscillator’s volume (amp).

Scale lets you control how much a target is affected by some other setting or control. For instance, you might want to use the modulation wheel so it will slowly turn up the amount of modulation you have setup. Setting the Scale to 127 (highest setting) will make it so there is no modulation until you start to move the mod wheel. The amount continues to increase as you move it.



The manual could use a bit of an update. It doesn’t mention “Rompler” as being one of the choices for the oscillators, and there are a few other omissions.  Another thing on my wish-list is for the Sequencer to be easier to use, and maybe have a couple functions added. The loading/saving of patterns for the sequencer would be a nice addition, as well as a swing setting, and some way to reset back to the default settings. 

The features that I really like in Helix are the many types of oscillators available, the semi-modular stage section, low CPU usage, and of course; its price is tough to beat. It has a great quality to its sound, and a large sonic range. It’s almost worth buying Helix just to get the BigTone presets that are included. They really sound excellent, and they showcase the many ways Helix can be used.

For what you get included in Helix, it is definitely a great value, especially at its new price of $75 USD. You’d be hard pressed to find something at this price that can do everything Helix can.  You can check out the audio demos and the PC/Mac demo versions of Helix on the Audjoo website here:





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