Apparently the reunited Doobie Brothers had such a gas getting back together and being on the road this summer, they're going to cut an album together--or at least some of them will. No recording contract has been signed yet, manager Bruce Cohn said Tuesday, but the new album--the band's first since "One Step Closer" in 1980--is targeted for release next spring. So far, the recording unit comprises the original leader, Tom Johnston, and other founding Doobies, vocalist/guitarist Patrick Simmons and bassist Tiran Porter. Drummers Michael Hossack and John Hartman have also expressed serious interest. But you can forget about the soulful-voiced Michael McDonald--who has a busy solo career going right now--joining them.