Number: 12 (coarse) 44 (fine)
This can control any parameter relating to an effects device, such as the Reverb Decay Time for a reverb unit built into a GM sound module.
NOTE: There are separate controllers for setting the Levels (ie, volumes) of Reverb, Chorus, Phase Shift, and other effects.
If a MultiTimbral device, then each Part usually has its own Effect Control 1.
14-bit coarse/fine resolution. 0x0000 to 0x3FFF where 0 is minimum effect.