Modifiers
Now you've got LFOs, envelopes, external MIDI controllers and so on. But how could these modulations interact, for example when you need a vibrato on the Filter where you control its strength by Aftertouch.
This is where the Modifier section starts. It offers you basic arithmetic calculations like adding, subtracting, multiplying and dividing plus lots of very powerful algorithms to tweak your modulation source signals in a musical manner. There are four Modifier slots that you can use for those purposes.
But first, how could you set up the Filter vibrato controlled by Aftertouch? In the Modifier section, you just select a LFO as one of the sources, Aftertouch as the second source and "*" (multiply) as type. That's all you need to do here. Of course, you have to tell the Microwave II/XT that it should change the Filter Cutoff, but this is done in the following section, the Mod Matrix. But let's stay at the Modifiers for a while.
For example, the Modifier type Ramp. It gives you an adjustable 1 stage envelope where only a linear increment is performed from minimum to maximum. You can control its rate and trigger it by any signal which switches from a value equal or below 0 to above 0 (a positive zero crossing, to speak with the words of a developer). You get those from an LFO or a controller.
A similar modifier is the Lag. It doesn't create only one ramp but it moves linearily from the last input value to the current input value. The rate of this movement can be adjusted. The effect is that it smoothes out the input modulation in a linear fashion.
When you need the same thing in an exponential fashion, take the Modifier type Filter. It really acts like a Low Pass filter, but on modulation not audio signals. This or the Lag modifier might be very interesting in a situation where you have a slightly unpredictable input signal like Aftertouch, which can be difficult to play on some keyboards. With the filter you can smooth out the value changes so that you don't get steps in your modulation. When you route this modifier to the filter cutoff, the result is a sweeping rather than a jumping cutoff modulation no matter how quick the Aftertouch pressure changes. Isn't that cool?
Other modifier types include boolean operations like OR, AND and XOR and further algorithms like sort of a high pass filter, minimum and maximum value, a switch, an absolute value transformer and a Sample & Hold Generator.
There is a fifth special Modifier, which is called Modifier Delay. It works like the name says, just delaying the modulation input by a certain time before it sends it out to its receiver.