Judge Barry Feudale's three-page order said "the interests of justice" would be served by providing the records earlier than required under state trial rules.
He said the estimate of 581 pages was based on a list of witnesses that state prosecutors have told him may be called to the stand in Sandusky's trial on 52 criminal counts.
The 68-year-old former Penn State assistant football coach remains on home confinement while he awaits trial, currently scheduled to begin in Bellefonte with jury selection on May 14. He has denied the allegations.
Messages seeking comment were not immediately returned Wednesday from his lawyer, Joe Amendola, and the state attorney general's office.
Feudale said the disclosure will occur 10 days before the first witness is sworn in, not the first day of jury selection. State criminal court rules say grand jury transcripts are available only after a witness makes his or her "direct" testimony, right before the start of cross-examination.
Feudale rejected Sandusky's request to get the transcripts by Feb. 28, or to get them 30 days before the start of trial. He also turned down the prosecution's request to keep them secret until a week or less before the trial starts.
The question of how to handle the grand jury transcripts is among a set of issues currently being worked out in advance of trial. Judge John Cleland, who is presiding over the case, has scheduled a Monday hearing regarding the disclosure of other material to the defence.
Sandusky is accused of sexual abusing 10 boys over 15 years, including inside the athletic facilities at Penn State, where he worked for decades as the football team's defensive co-ordinator.
He was arrested in November, along with two university administrators who are charged with lying to the grand jury and failing to properly report suspected child abuse. Athletic director Tim Curley, now on leave, and vice-president Gary Schultz, who has retired, are asking to have the charges against them be dismissed.
The allegations have left a black mark on one of major college football's most prominent programs, and led to the firing of former coach Joe Paterno before the end of the 2011 season. Paterno died of lung cancer in January at age 85.
Feudale order: http://bit.ly/zOR1pg