Spectral Audio Neptune II review

  • £333
A fabulously analogue sounding synth!

MusicRadar Verdict

The Neptune 2 is a charming piece of gear that's like something from another time - a full fat classic.


  • +

    Great analogue sounds.


  • -

    Quirks may not appeal to everyone.

MusicRadar's got your back Our team of expert musicians and producers spends hours testing products to help you choose the best music-making gear for you. Find out more about how we test.

Releasing hardware synthesizers right now in our industry's development seems either very brave or very foolish.

Established, well-known manufacturers such as Waldorf are continuing to produce standalone instruments but many other companies which started this way, including Access and Novation, are increasingly 'bending' their products to acknowledge that most of us spend our days making music in front of computer screens.

Accordingly, there are now dozens of hardware synths with FireWire or USB connectivity, offering instant integration into our Mac or PC-driven audio sequencers. Flying in the face of such technological hand-shaking comes a revised version of Neptune 2. Here's a true hardware monosynth whose closest nod to 21st Century integration is the provision of a couple of MIDI ports.


There's a reasonable chance that many of you reading this will never have seen the original Neptune but for those of you with a unit or a photographic memory, you'll note that the slightly unpleasant creamy-orange livery has been replaced by the new altogether more stylish royal blue.

Visual overhauls are one thing but no synth sells by its looks alone and while Neptune 2 doesn't look to completely overhaul its ancestor's feature set, some important improvements are now offered.

Firstly, this is now a synth that properly behaves itself while you're editing, with smoother and more even response from its potentiometer knobs.

This might sound trivial but as you'll spend at least 80% of your time with this synth twiddling dials, it's much better to work with a box that offers a predictable response.

The front-panel LEDs have been improved too, with larger, bright light-blue LEDs dotted, where relevant, all over Neptune 2. These are much easier to see and use than before and do a useful job, particularly in the LFO section.

Additional front-panel functions have been included too, with a Keyfollow toggle switch in the filter section and a 'Free Run' button within the switchable LFO/Osc 3 section.

The first of these allows the filter's functionality to be affected by an incoming pitch, whereby higher notes open the filter more than the lower notes. The toggle allows three positions with full and 'half' operation alongside the option to switch key-follow off altogether.

The 'Free Run' button allows Oscillator 3 to operate without being tied to the keyboard, so that it doesn't track incoming pitch. Further improvements include a 'truer' white noise generator, which now generates noise all the way up to 100kHz. To round off the new functions, Neptune 2 now features a dedicated power button labelled, rather sweetly, 'Energy'.


So, what does all of this mean for the Neptune 2's sound? Well, it's pretty fabulous, as you can hear on the DVD. Neptune 2 shares its predecessor's pure DC design, which means that there are no capacitors involved in production of a signal here at all.

When working with the internal waveforms, there's almost no audible noise and, factoring these points together, this all equates to a gorgeous pure monosynth sound.

Set against the 'digital/ analogue' hybrid noise produced by some modern synth clones, working with this instrument is akin to getting behind the wheel of a vintage Aston Martin - pure retro class.

It's capable of some surprising results too, not the least of which is it's rather wonderful approach to routing LFOs into the signal chain.

Four separate buttons allow you to send the LFO waveform of your choice into any or all of the two Oscillators, the filter cutoff and the Mixer section, which in turn handles the volumes of each Oscillator and the Ring Modulator.

As the LFO's speed is variable across a huge range, with six choices of waveform including a random wave generator as the source, you can begin to imagine the carnage, which can be applied to the main signal. Gloriously, the LFO can be clocked via MIDI too, so this can all happen in time with your track if you like.

The new improved noise generator is also capable of some very special things, especially when used alongside one of the two onboard 'effects'; distortion and fuzz. These both provide their own individual flavours of grit and some sensational things can be achieved when blending a noise generator at Oscillator 1 with an 'External', audio in waveform at Oscillator 2.

As both sounds are governed by the same filter and envelope settings and independently balanced within the mixer, it's possible to 'glue' very different sound sources together, often with results that make you grin maniacally from ear to ear.

If there's a place in your heart, a studio for monosynths and sufficient cash in your pocket, try to find a Neptune 2 and divert yourself for an hour or so with its charms; it's an instrument that grows on you.

Like all true analogue synthesizers, it's full of quirks and foibles but these soon become almost pleasant eccentricities the longer you spend in the company of this strange blue box; there's no expectation that it can do 'everything' and accordingly, you revel in what it does do and learn to draw from its strengths.

Whether you're interested will entirely come down to whether or not you have the inclination, budget and patience for something really 'unusual' in your studio, so the acid question is - do you?

Future Music

Future Music is the number one magazine for today's producers. Packed with technique and technology we'll help you make great new music. All-access artist interviews, in-depth gear reviews, essential production tutorials and much more. Every marvellous monthly edition features reliable reviews of the latest and greatest hardware and software technology and techniques, unparalleled advice, in-depth interviews, sensational free samples and so much more to improve the experience and outcome of your music-making.