Last in Line's debut album may not be out for a while yet, but don't assume the band members have lost their passion for the project.

"It's the best band I've ever been in as far as ... you know, from the beginning it was great, when it started," drummer Vinny Appice told Totally Driven Radio, recalling the band's decades-old beginning as three-fourths of Dio. "And since then, I've been in a lot of different bands and this is just, like ... I look forward to going there and hanging out with everybody. We have a great time. The ideas are flowing, the creativity is there. It's just a nice atmosphere. I love those guys."

Reflecting on the series of dates Last in Line did in 2014, Appice added, "It's amazing to play these songs and see these people still going crazy for them, and they're thirtysomething years old. We're part writers in them. So it's a good feeling."

Appice -- who started Last in Line with fellow Dio vets Vivian Campbell, Jimmy Bain and Claude Schnell before the band brought in singer Andrew Freeman -- promised that the album "sounds amazing," but could only speculate that it'd be out "sometime later" in 2015.

Campbell revealed the reasons for the lack of a release date during a visit to Eddie Trunk -- and unsurprisingly, they have a lot to do with his Def Leppard commitments, which look to be fairly significant in the coming months given that the band is planning a new album and tour.

"It doesn't make a lot of sense to put it out there if we're not available to support it," said Campbell. "And I've got a really, really big schedule with Def Leppard this year, 'cause Leppard have a new record coming up also, backed up by a world tour. So I literally don't have a lot of availability to do Last in Line shows. And it would be a real shame -- especially because the record is sounding so much better than we all anticipated -- it would be a real shame to just put it out there and let it die."

If they can find enough "holes" in the Leppard schedule to work in some Last in Line dates, Campbell anticipates getting the album out this year; if not, he suggested "we'll just kick it down the road until everyone's available to do it."

Campbell also took the opportunity to respond again to the argument that Last in Line is somehow besmirching the Dio legacy by performing material they originally recorded with deceased frontman Ronnie James Dio -- and although he and Appice have both taken pains to point out that they helped write many of those classic songs, Campbell conceded that the project never would have happened if Dio were still alive.

"It's not like the day I heard the news that Ronnie had passed that I was starting to put the wheels in motion or anything. It's just something that kind of ... it organically grew," said Campbell. "One thing led to another. But, yeah, it is fair to say ... I wouldn't have felt right doing it if Ronnie was still out doing his thing."