In general, digital synthesis provides many more sounds than analog synthesis. But wouldn’t it be great if you could process an FM synthesis sound with the richness of two analog-style multimode filters? Well, that’s exactly what Operator Z does in Native Instruments FM8!
Operator Z is a special-class operator. Imagine if you could use two separate 2-pole 24dB multimode filters to sculpt your sound. Operator Z has a Cutoff control that sets the initial cutoff frequency of both filters. Reso(nance) works similarly, and sets the degree of resonance (amount of boost at the cutoff frequency). Mode performs the same function for each filter. It allows users to set the response mode in a variable fashion from lowpass, bandpass, and highpass. Finally, the cutoff spread applies to Filter 2 only. It offsets Filter 2’s frequency compared with Filter One. Finally, the Filter Mix changes the balance of the output of the two filters, from only Filter 1’s output, to both outputs to Filter 2 only.
There are additional controls, as well as envelopes, modulators, and so forth, but the bottom line is that by using Operator Z, there are many more tweakable parameters, all of which can be used to add analog-style sound quality to what is essentially a digital-only output. Don’t expect instant gratification, but always be prepared to save programs that please your ears as you encounter them.