** 1/2 ROBERT PLANT “Manic Nirvana” <i> Es Paranza/Atlantic</i> .<i> Albums are rated on a scale of one star (poor) to five stars (a classic). </i>

Nope, this isn’t it.

Former Led Zeppelin singer Robert Plant still hasn’t come up with that macho, hard-rock album Zep fans have been waiting for since the band called it quits a decade ago.

His solo albums--this is his fifth since 1982--are like public dress rehearsals for the real thing. His last one, 1988’s “Now and Zen,” was a disjointed, dissonant mess, wandering all over the place. The new one is more focused--with guitars a stronger force than usual--but some of the pieces still seem cluttered and aimless, tottering on quirky rhythmic structures.

Plant is apparently still experimenting, seeking a new niche. Meanwhile, he keeps Zep fans salivating with numbers, like “Nirvana,” that have tantalizing echoes of good old Zep. The album’s best song is a remake of Kenny Dino’s 1961 hit, “Your Ma Said You Cried in Your Sleep Last Night,” mainly because it’s fairly close in spirit and feel to old Zep tunes.

It’s time for Plant to stop pussyfooting around, come to terms with whatever he has to come to terms with and make that good, hard-rocking, Zep-style album that’s obviously lurking inside, clamoring to get out.

C’mon Robert, we’re getting tired of waiting.