Birch was the first outside producer the band had used since 1971 's Master of Reality , as Iommi had primarily produced the band 's albums since that point on his own .
Dio suggested the band hire producer Martin Birch for the album .
Martin Birch was the first outside Martin Birch the band had used since 1971 's Master of Reality , as Iommi had primarily produced the band 's albums since that point on his own .
Dio suggested the band hire producer Martin Birch for the album .