"MDL" is a parameter that sets the degree of modulation (how much modulation is applied) by the modulation signal applied to the modulation inputs X and Y. Increasing this value deepens the frequency modulation, and decreasing it makes it shallower (Figure 4.38).
Figure 4.38 MDL modulation depth
Explains the degree of modulation by the “MDL” setting value. Table 4.15 shows that the modulation factor becomes ± nπ depending on the set value of “MDL”.
∙ Each sound slot data input to modulation input X and Y is averaged by the averaging calculator. If the data input to X is XD, the data input to Y is YD, and the output of the averaging operation unit is ZD, it can be expressed as the following equation.
ZD = (XD + YD) / 2
こ の This ZD is subjected to level adjustment by "MDL" and sent to the slot address pointer (phase adder).