The complete functionality of BLUE-II is far too vast to cover here. All the functions of a typical synth are there, but it goes far beyond that in terms of the specific options available and in routing and modulation. The signal path starts with six oscillators that can be connected however you wish, affecting each other with frequency, ring or phase modulation, or syncing to the first oscillator. Phase distortion and waveshaping can affect the shape of each waveform, and there's a huge range of these waveforms available. Each oscillator has the usual tuning, key tracking, level and pulse width modulation. There are some more exotic controls as well, including a sub-oscillator on each, a spread control to fatten them with side tones and a drift control to add vintage-style pitch drifting. They even include controls that detune the oscillators by intervals, which gives usable results for frequency modulation.
There's a thorough selection of filters with different slopes, and the two filters can be arranged in series or in parallel. (The oscillators can each be routed individually to go either through these filters or straight to the effects or output.) Along with the usual frequency, resonance and modulation controls, there's also a control that can add filter distortion or adjust the character of the vocal or formant filters.
In terms of modulation, BLUE-II's options feel limitless. The dedicated source modules include a multistage envelope, a modulation sequence and an X-Y grid. The grid, taken from Papen's Blade synthesiser, is particularly unique—you can assign as many as four parameters to each side of the square and record a complex path in the grid, that's then followed with selectable behaviour. You can modulate parameters from LFOs, from the oscillator and filter volume envelopes and even from the oscillators themselves, from an external input or from the output of the whole instrument. The list of modulation destinations, meanwhile, seems to include absolutely everything possible.
There's an advanced 32-step sequencer, where you can vary a range of parameters, which even include oscillator wave type, with each step. The 32-step arpeggiator is similarly advanced, including note length and a range of different modes. Both of these have controls over swing and accent, allowing you to create rhythmic patches with a groove of their own. There are four effect slots, the effects are high quality, and there are, you guessed it, lots of them available. There are often several varieties of each effect, with staples like reverb, phaser, EQ and so on, through to things like amp and cabinet simulation, a trance-style gating sequencer and wah-wah delay.
Despite BLUE-II being a sound designer's dream, you don't need a doctorate in the subject to use it. This is partly because it has an intuitive layout, with functions nicely organized on various pages. Mainly, though, it's because the preset library includes a wide range of very usable patches. They're organised in 32 sensible categories of 128 presets each. This means you can find something close enough to what you're looking for and tweak it, rather than designing everything from the ground up. (The CPU usage of each patch varies—the more complex patches could eat as much as 50% of my eight-core 2.8 GHz Intel Mac's processor power when holding down a chord, but most were much less, allowing multiple instances in a session.) It also has an "easy mode," in which one panel gives access to various macro controls. These macros generally give global control of particular parameters, varying, for example, all amp envelope times of all oscillators together.
All of this wouldn't be very useful if it didn't sound good, and thankfully the synth comes through in this area as well. It feels quite neat and precise, which is partly down to the amount of control you have over the sound, but also because what comes out the speakers sounds accurately sculpted. It has a lot of punch, clarity and presence. It can go almost anywhere you choose sonically, although if you're looking for an authentic vintage character, an analogue hardware synth or emulation might be more appropriate, as the drift control can only go so far. Rather than occupying that kind of niche, though, the BLUE-II is a synthesiser that can do pretty much anything—and what's more, it does it all while sounding confident.
Ease of use: 4/5