The 51-year-old man, Colin Harold Doo, pleaded guilty to 39 charges including 10 of procuring a child for the purposes of producing pornography, six counts of rape and 12 of committing an indecent act in the presence of a child under 16.
Doo met the victims at a primary school where he was a music teacher. He drugged one of his 11 victims, aged 10 before raping her three times while she was unconscious, The Age reported.
He set up a toilet in one of the two rooms he had in a backyard shed of his father's property in central Victoria.
He rubbed sex toys over some of his victims and touched them repeatedly. One victim recalled that he always had chips, lollies and video games for his victims.
The effect of Doo's offending on his victims and their families has been "very serious", Supreme Court Justice Paul Coghlan said while pronouncing the judgment.
The court described the victims as very vulnerable because they were aged between 10 and 17 and at a crucial point of their development.
"It is yet another example of consequences of offending against children and in particular offending in small communities," Justice Coghlan said.
"The personal hurt you have caused these people is vast and it is obvious," the judge said, adding that the trust the victims' families had placed in him had been breached in the worst possible way.