There's no pop because you just swing a full motion, never concentrating the rackethead speed anywhere.
You need to swing fast upwards, slow down your hand to "crack the whip", then followthru after impact. A high hand, high elbow finish, after the ball strike, with your racket pointing straight down at the ground, shows you this.
Look at vids of pro men's serves. After the ball strike, the hand and elbow is above their head, while the racketHEAD is pointing straight down at the ground.