There are six Modulation Effects: Flanger, Dual Flanger, FM Chorus, AM Chorus, Phaser, and Symphonic. These are the usual variations of the common flange/chorus effect. The FM Chorus utilizes frequency modulation of the effect while the AM Chorus program uses a less subtle amplitude modulation of the chorus effect. There are four Pitch Change Effects: Mono Pitch Change, Dual Pitch Change, Triple Pitch Change, and Stereo Pitch Change. The Mono, Dual, and Triple Pitch Change effects produce one, two, or three pitch shifted signals at the output. The Stereo Pitch Change program is a true stereo pitch shifter with parameters that effect both channels simultaneously. The SPX-990's pitch programs also feature an "Intelligent" parameter that enables the algorithm's ability to change pitch according to a user selected musical scale.

There are two Pan Effects: Auto Pan and Triggered Pan. The Auto Pan is more complex than most similar pan programs. Along with the usual left to right panning, you also get "front" to "rear" panning. There is only one Freeze or sampling effect. The maximum sampling time is 1.35 seconds, and samples can be looped and pitch shifted. Other functions of the Freeze Effect include overdubbing, reverse playback, and editing of start and end points.

Finally, there are eight Multi-Effect effects: Chorus & Reverb, Symphonic & Reverb, Flanger & Reverb, Reverb(L)/Reverb(R), ER(L)/Reverb(R), Echo(L)/Reverb(R), Chorus(L)/Reverb(R), and Pan(L)/Pan(R). Some of these effects are "multi-effect" programs in that they apply more than one effect to both left and right inputs. The latter programs are "dual effect" programs that apply a different effect to each input such as echo to the left channel and reverb to the right channel -- Echo(L)/Reverb(R). Combined with the available Pre-effects and Post-effects mentioned earlier, it's possible to get up to four, high quality effects simultaneously.

Nearly half the factory presets are reverb programs. The other half is comprised of various delay, pitch, and modulation effects with a few programs utilizing the pan, sampling, and distortion algorithms. There are certainly enough factory presets and a wide enough variety to make the SPX-990 a good pick for the person who hates to program these boxes. On the other hand, editing the programs is easy enough to entice even the novice programmer into an enthusiastic session of creating new effect programs.

Some high quality effects boxes go overboard with the number of parameters available to the user, sometimes making the editing process an arduous task. Other boxes don't provide enough parameters to make the unit versatile. The SPX-990 is pleasantly somewhere in the middle.

As expected, with 20-bit processing, the effects are all very clean. You get full 20-20kHz frequency response, dynamic range above 100dB, and noise below -82dBm. The new Memory Card feature could prove to be one of the nicest improvements to the SPX line, especially if someone writes 100 "radio production" programs and makes them available to other SPX-990 owners in the broadcast industry! The card is much less intimidating to the non-MIDI user than bulk MIDI data dumps and transfers, and it's much more convenient.