A former member of Melbourne’s Jewish Yeshivah Centre did a great deal of damage to nine boys he sexually abused, a judge said as he jailed him.

David Samuel Cyprys, 45, was associated with the centre as a locksmith, karate instructor and youth group leader and assaulted the boys between 1983 and 1991.

He was jailed for eight years on Friday after a Victorian County Court jury convicted him of five counts of rape against a 15-year-old boy when he was associated with the Yeshivah Centre.

Cyprys also pleaded guilty to sexually abusing eight other boys.

The victims were aged between seven and 14 and were students at the St Kilda Orthodox Jewish school Yeshivah College when Cyprys touched them inappropriately and in some cases used force.

Judge Peter Wischusen noted Cyprys was in a position of trust and authority and said his crimes did a great deal of damage to his victims.

He jailed Cyprys for a minimum five-and-a-half years.

Cyprys took notes in the dock and showed no reaction during sentencing.

One of his victims, Manny Waks, the head of victims advocacy group Tzedek, was in court.

“I just wanted him to see me there,” he told reporters outside court.

“It’s not about particularly rejoicing in someone else’s pain – he’s going to be suffering for the next few years.

“It’s all about justice.

“He thought he was able to carry out his unspeakable repeated crimes against so many children and today was our day to finally get justice.”

Mr Waks, who said he has lived for decades in silence with shame and guilt, was happy with the outcome, although no sentence would undo the damage done.

Cyprys is the second child abuser linked with the Yeshivah Centre, an umbrella group that includes Yeshivah College, a synagogue and a bathing house.

Former Yeshivah College teacher David Kramer, 53, was sentenced to three years and four months in July for groping four boys between 1990 and 1992.

The Yeshivah Centre’s principal, Rabbi Yehoshua Smukler, said the organisation hopes Friday’s sentence will deter other offenders.

“We recognise that the effects of abuse are profound and we empathise with the victims and their families, and hope this sentencing will facilitate a degree of comfort and closure,” he said in a statement.

He said the centre offers support and counselling to those who desire it.

“Today, at Yeshivah College, we employ absolute best practice and we are vigilant in ensuring the safety of the most vulnerable members of our community – our children,” he said.