The ornamental design for an amplificationdevice, as shown and described.
FIG. 1 is a perspective view of an amplification device in accordance with our new design;
FIG. 2 is a front side view thereof;
FIG. 3 is a rear side view thereof;
FIG. 4 is a left view thereof;
FIG. 5 is a right view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The dot-dot-dash broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are included for the purpose of illustrating portions of the amplification device; the broken lines form no part of the claimed design.