When it comes to satisfyingly elaborate synth engines, Waldorf are the go-to. A respectable name in the high-end synth game, Waldorf always mean serious business, which is exactly why we're treated to sweet synth chunks like the Iridium. The engine at the core of this module is so extensive that it'll take years before you hear everything it can do and even then, you'll still be wondering if you really have heard everything. The original Iridium is a keyboard synthesizer so, if you already have a perfectly good keyboard at your disposal, then the Waldorf Iridium Core is a more flexible and desktop-friendly alternative. This edition is not only more compact and free of a keyboard, but also comes at a slice of the price. The Waldorf Iridium Core Just like the keyboard edition, this is one serious bit of kit. The 12-voice polyphony is backed up by three oscillators per voice, and its in the oscillators where you can really make your mark: wave table, the wave form, particle, resonator or kernel. Wave table speaks for itself: simple sample playback, 2GBs of which already comes preloaded onto the flash memory. Here, 'waveform' is another word for virtual analogue, so you can mess around with your sawtooth and square waves and so on. Particle deals in sample-based granular synthesis. Resonator opens up a world of acoustic instrument simulations and, to finish, 'kernel' basically means FM synthesis via a maximum of six coupled sub-oscillators. On top of that, expansive filter options are on offer alongside a massive modulation matrix and enough effects to fill the boots of the most demanding of producers. Who's it Built For? While this model does have a few less control elements than the earlier edition of the Iridium module, is that going to be an issue? In a word: no. Everything can be done via the giant 1024 x 600 pixel display screen anyway. The Core is also fully compatible with the Iridium and Quantum, supporting patch-swapping. Basically, this model brings a whole horizon of sonic options but packs them away in a more compact box and, while the controls are fairly straightforward, the sheer breadth might be a bit overwhelming for the beginner synth-head, while more experienced producers will have more than enough to chew on.