Ozzy Osbourne says Black Sabbath's '13' is ''mind-blowing''.

The upcoming album will be the band's first since 1978's 'Never Say Die!' to feature three members of the original quartet - with bassist Geezer Buttler and guitarist Tony Iommi reuniting with Ozzy - and the frontman is ''over the moon'' at the finished piece.

Speaking to Australia's Triple M radio station, Ozzy said: ''The album is mind-blowing, [that's] how good it is. I'm so over the moon about the way the album turned out.

''We wrote 16 songs ... and I put it on my CD player expecting me to be unhappy with the end result, but this big grin came on my face and my hair on the back of my neck [stood up]. It's better than my wildest dreams; it's so good.''

'13' will include three seven-plus-minute tracks - 'End Of The Beginning', 'God Is Dead' and 'Epic' - and Ozzy is thrilled the band have managed to recapture their ''heavy'' roots.

The rocker, who left Black Sabbath in 1978 and then reunited with them for a world tour in 2011, added: ''Believe me, I'm the guy that goes, 'Ah, there's a mistake there.' I look for the mistake. If there's one mistake, I'll find it. But this album is great, perfect.

''It's very, very heavy, there's no getting away from the fact that it is Black Sabbath, and you can hear every instrument and everything clearly. It's so heavy. I'm so excited about it.''

The album is expected to be released in June.