Brian “Head” Welch says it feels good to be back in Korn. But his return didn’t come easy. The guitarist left the group in 2005, after 12 years and seven albums, and still calls his departure a matter of personal survival.

“Ever since I’ve known these guys we have been just getting into trouble, and then we got successful and got into trouble while we were making a great living and becoming rich and famous,” Head tells Billboard. “I couldn’t be around people killing themselves anymore. As far as people doing cocaine or just drinking themselves into a crazy alcoholic and watching people’s lives slip away, I can’t be around that. It was really dysfunctional and unhealthy, so I just needed to get away from that.”

Head reconciled with the other members of Korn during a guest appearance onstage in May of 2012, and the response — from fans, family and even other bands, he says — “was so strong that it as like, ‘This has got to be meant to be’ and they asked me to do an album with them and that was it. It’s cool to see these guys were working on their lives while I was away from the band, getting their stuff straight, too.”

Head says the resulting album, “The Paradigm Shift” — which debuts atop the Hard Rock Albums chart and at No. 8 on the Billboard 200 with 46,000 (the band’s 12th top 10) — was the result of a different kind of head-butting, a creative collision of sensibilities that he found enjoyable as well as challenging.

“We wanted it to sound familiar but like the future at the same time,” he explains. “I wanted to do a full-on rock record, ’cause I’m a metalhead. But then Jonathan (Davis) and the producer (Don Gilmore) and the guys wanted to have a really fresh sound, so we were talking about doing it a little bit sprinkled with electronic and some really cool new sounds to make it sound 2013. We didn’t want to just go backwards and do an old Korn album. We wanted it to be fresh, and I think we accomplished exactly what our hearts wanted to do.”