DigiTech Midi Implementation Manual page 177

Delay Time Tap4 ( 0-222)
see Delay Time
Digital Reverb (0-1)
0 Off
1 On
Digitube Gain (0-21)
Digitube Level (0-10)
Distortion (0-1)
0 Off
1 On
Distortion Balls (0-31)
0 0.6
1 1.0
2 1.3
3 1.6
4 2.0
5 2.3
6 2.6
7 3.0
8 3.3
9 3.6
10 4.0
11 4.3
12 4.6
13 5.0
14 5.3
15 5.6
16 6.0
17 6.3
18 6.6