Quad Operator

An FM synthesizer without fixed algorithms for the Operators. Sounds like a big deal, but Humble Audio has managed to pack the functionality into a 30HP package without skimping on the overview. Waveshaping and external audio input still included.

As the name suggests, the module offers four operators, each having separate ratio, detune and shape controls to set the tuning and waveform. The operators are, therefore, not limited to sine, but also provide triangle, square and sawtooth waveforms as well. Ratio and shape, as well as gain of the operators can be influenced via CV inputs, which still provides lively sounds without the actual FM synthesis.

The mutual modulation of the operators is controlled by a 4x4 matrix. If you add envelopes and LFOs, there are no limits to the sound design options and everything is possible: booming sub basses for the heaviest Drum & Bass or Dubstep, sawing lead sounds with bite, bubbling alien effects, house organs.... the list could go on and on. And thanks to the audio input, the sound palette is boosted even further. On the output side, all of the operators can be tapped separately.

With the separately available Algo Expander (99 Euro), tweaked sounds can also be saved and crossfaded.

Verdict

It‘s not hard to see that we were impressed by the Quad Operator. Although the price is quite steep (for the same money there are already compact desktop synths with effects), but even in direct comparison, the Quad scores with much more haptics, faster operation and more flexibility thanks to the audio input.