This spectral synth proves to be another worthy addition to the Reason Rack.

Propellerhead's latest Reason Rack Extension is a spectral synthesiser running two mixable Sound Engines, each comprising a Generator, a combination low-pass/high-shelf filter, and two Modifiers.

The Generators offer a menu of 12 additive signals, each using up to 512 partials, and including the analogue-style Saw->Square and Dual Saw, as well as FM, Noise and several decidedly spectral options.

As well as tuning/ pitching and keyboard tracking, the Generators host one contextual control knob each, the target parameter of which varies by type: Mix for Saw->Square, for example, Modulation for FM, or Stretch for String.

"It's a broad and well-thought-out collection of sonic starting points"

It's a broad and well-thought-out collection of sonic starting points, although it needs to be stated that Parsec can't import and resample external sounds. Placed after the Generators, the filters feature a Slope control for setting the cutoff slope/mode anywhere between 100dB/octave roll-off and +12dB high shelving.

Each of the four Modifiers gives a choice of 22 frequency-tinkering algorithms, including additive emulations of a wide range of conventional and more outré filter types (Formant, Partial, etc), as well as PWM, Ensemble (chorus), Unison, Audio Input (additive vocoding!) and more.

Each Modifier features two contextual knobs: Pulse Width and Mod for the PWM module, for example. While that might not sound like much in terms of editability, the controls boast plenty of range and sensitivity, and there's no arguing with the ease of use they impart.

Lots of modulation is on tap, courtesy of two LFOs and three envelopes (one dedicated to the amp), routable via the same kind of modulation matrix as found in Reason's Thor synth (two destinations per source, scaling, etc). 3Finally, you get reverb and delay effects to play with.

Parsec makes for a very worthy addition to the Reason Rack, being powerful, sonically striking and supremely easy to use. As is the Propellerhead way, it also ships with a ton of superb categorised preset patches that ably demonstrate its versatility. Our only criticism is that the Modifier displays aren't animated at all - they look like they should be - but that's a very minor quibble indeed.