"I miss him every day," says Collen. "He was my best friend, we had the best time together, and it was a very rare experience to meet someone like that - and I have a similar relationship with my wife, we are best friends. And, like I say, it doesn't come up very often."
It's been 20 years since Clark died but his legacy and riffs live on in hits such as Photograph, Armageddon It, and Animal. The band play one of his finest - and fiercest - songs, Switch 625, on their current tour, which hits Auckland on October 12 at Vector Arena just three years after their sold-out show for tenth album Songs from the Sparkle Lounge.
Switch is a rip-snorter of a track ("It reminds me of him. He's always there," says Collen), and a heavy stomper compared to the pomp and power pop metal of 1983's Pyromania and 1987's Hysteria. Collen joined the band in 1982 and played on Pyromania, but it was on Hysteria - the band's best and biggest-selling album - when he started writing songs and playing a bigger part in the band.
Although he's a little coy about his role. "I just added my thing, which was some new wave, some funk stuff, different types of things that the band hadn't done before. So we were able to push it a little bit further."
As well as playing guitar he could also sing - "they didn't have that big vocal sound with everyone singing" - and so the world has Collen to thank for big Leppardised sing-alongs like Pour Some Sugar on Me and Love Bites.
The current line-up of Collen, rough and ready frontman Joe Elliott, fellow shirtless guitar player Vivian Campbell, one-armed drumming machine Rick Allen, and glam bass player Rick Savage, have been together since 1992.
On the side Collen has also hooked up with Sex Pistols' drummer Paul Cook and bass player Simon Laffy (who was a bandmate of Collen's in one of his early London bands, Girl) who are known as Man Raze.
The band released their debut album in 2008 and they have just finished recording their second which comes out in August.
But it's Def Leppard that's the giant rock monster that never stops. This month they put out their first live album, Mirror Ball, a three-disc mecca of hits, fan favourites, and newer songs. It seems remarkable in a career that spans 35 years, 10 studio albums, and around 65 million record sales, that they have never released a live album.
"Not really," laughs Collen, "because we do album, tour, album, tour ... but we took our first year off in 30 years last year so we had a bit of time to actually sit around and listen to [the live recordings] and we compiled Mirror Ball."
They went about the track listing very much the same as how they go about compiling a set list because Def Leppard know the score. As Elliott said last time he talked to TimeOut: "We'll play a combination of our new album and our classic tracks, some of which we will get castrated if we don't play."
Collen says Def Leppard still has a lot to do, which is what keeps them going.
"And the main thing is we like each other," he laughs.
"We've experienced a lot of life together - from young boys to middle-aged men, and there have been deaths, births, marriages, divorces and we're always there together. And we love each other like brothers. It's really cool. So we have that and a lot of bands don't, we still have that fun thing."
Lowdown
What: Def Leppard
Where and when: Vector Arena, Oct 12
Latest album: Mirror Ball, three-disc live album
Classic albums: Pyromania (1983); Hysteria (1987)
- TimeOut
