Saying that he's "just ready to get off the road," AC/DC bassist Cliff Williams repeated his plans to retire. His last concert with the group will be tonight at the Wells Fargo Center in Philadelphia, the band's final stop on the Rock or Bust tour.

AC/DC released a new video from Williams, who confirms his departure. After thanking and praising the fans for their support, he says, "It's time for me to step out, and that's all. Not because we've lost Mal[colm Young], Phil [Rudd] or Brian [Johnson]. I mean, everything changes when something happens like that. When Bon [Scott] died, it changed then. You know, everything changes, so it's not that."

You can watch the video above.

Williams' words are slightly different from his initial comments back in July, when he said the band's recent personnel shifts were at the heart of his decision. “Losing Malcolm, the thing with Phil and now with Brian, it’s a changed animal," he said at the time. "I feel in my gut it’s the right thing.”

Now Williams, who'll turn 67 in December, is framing his retirement more in terms of a well-deserved break after spending most of his life playing rock 'n' roll. "I'm just ready to get off the road, really, and do what I do," he notes. "In between tours, we take a few years off, so I know how to do that, I know what I'm gonna do. Again, it's just my time. I'm happy. I just need to -- family time now -- just chill out and not do this. I mean, I couldn't have asked for anything more, being with the people I'm with and have been, and being in this situation with this band, playing this music."

Williams joined AC/DC in 1977; Powerage, released a year later, marked his recorded debut with the band. Guitarist Angus Young remains AC/DC's only founding member Drummer Chris Slade, who was in the band from 1989-94 and then rehired in 2015 following Rudd's well-documented legal problems, is the group's next longest-serving member.

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