Of course, it's not really Don Draper, because Don Draper is a fictional character from Mad Men, the critically acclaimed television show set in 1960s New York about advertising executives. I am on the Los Angeles set to meet Vincent Kartheiser, who plays the odious Pete Campbell; the man with the iPhone is Jon Hamm, the square-jawed heartthrob who plays Draper - in character but taking a break between scenes.  Before I can ask Hamm who his tailor is, a studio publicist briskly leads me to another seating area, where Kartheiser has just arrived. He has finished a scene - like Hamm, he is still in character - and wears a heavy, double-breasted suit that must be uncomfortable in the LA heat. An impressive set of sideburns adorns his cheeks, fitting the new series, which is set in the late 1960s. His hair is swept into a parting and a corner of his hairline has been shaved to make it appear as if he is balding.  Mad Men characters live intense, volatile lives - Kartheiser's, in particular, spends most of his time grappling with an existential torment that manifests itself by cheating on his wife and nurturing a resentful inferiority complex. With that in mind, I wonder how easy it is to relax between takes. Kartheiser shrugs. "My head is here," he says, after we sit down. The cast, he explains, have different ways of passing time. "Right over here we have a game table. In between scenes you can play dominoes or cribbage."  Wow, I think. These Mad Men actors really know how to party.  "We all listen to music and dance and tell stories," he says, making it sound like a summer camp. "It's a real light set. The work we do is pretty heavy so we can try to keep it easy … easy, breezy, cheesy Mc-freezy."  This riff is fairly typical of Kartheiser, as I discover during my hour with him. He is slightly manic at times, adopting a range of theatrical voices and accents (at one point he leaps to the ground, snarling and growling to show me how he intended to play a demon-killer on Angel, a Buffy the Vampire Slayer spin-off). The contrast with the insecure - and rather unpleasant - Campbell could not be greater. But maybe that is the point. Is he deliberately trying to distance himself? "I have a lot of issues myself," he says, laughing. Such as what? "I'd rather not say. I'm obnoxious at times as well, but I think in different ways to Pete." The demands of the role can take a toll. "After doing 12, 13 episodes it does tend to wear on you. If you frown for 13 hours a day it does have an effect on your life."  I mention other interviews with him: one, in particular, in a publication from his home town of Minneapolis, revealed that part of his weight-loss and exercise regime included having sex (he described it in slightly less FT-like terms) "for a few hours" every night. Another explained that he psyched himself up between scenes by shouting and hollering. "I do less of that now," he tells me, referring to the shouting. "Today I was feeling a little bit stale so I hopped around and did some of the vocal exercises that I used to do."  As for the sex-as-exercise line, he looks a little abashed. "That's what happens when you get interviewed for three hours," he says a little regretfully. "My demeanour on set or photo shoots … I try to be funny and entertain people."  I thought the sex line was funny, I say.  "My parents didn't. It was on a local paper in my parents' neighbourhood. So my parents are calling me up and saying, "What the hell are you talking about! You look like a scumbag!"  Born and raised in Minneapolis, Kartheiser, 33, is the youngest of six children and has been acting since he was six, starting in local theatre and then moving into films in his teens. His father sold construction equipment and his mother ran a nursery and they encouraged him to act. "I didn't have a lot of friends at school and in theatre I found a group of friends. A community of people who really believed in me and cared about teaching me and treating me like an equal. I didn't feel like a kid with them. I felt like a peer and we were making something together. That was a great feeling as a young person, to feel like you're … essential."  A man appears behind me. "They want you," he says to Kartheiser, who has to shoot another scene. "Want to walk with me?" We spring up and start walking towards the sound stage, the heat rising a few degrees as we step out of the shade. I mention Money, the BBC adaptation of the Martin Amis novel that he starred in 2010 alongside Nick Frost. He enjoyed it but said it was a contrast with work in the US. "You're working six-day weeks, the trailer has no heat, the food is a little bit like … gruel. It's very much like… " He puts on an Oliver Twist accent: "Can I have some moooore?" We reach a door that leads into the sound stage. "This is where I leave you," he says, grinning; the door opens and he slips into the darkness.  I walk back to the seating area outside the trailer and 15 minutes later there is a screech of brakes; Kartheiser has pulled up on a bike, which has 30 ROCK emblazoned on the frame. "I borrowed Johnny Hammersticks' bike," he says. Who? I ask, blankly. He looks at me like I'm a moron. "Who do you think Johnny Hammersticks is? Jon Hamm!"  He slumps into the chair next to me - he has taken off the shirt and suit jacket and is wearing a white T-shirt. "Today was a long day. Draining." I ask about living in Los Angeles: his family is still in Minnesota but LA is where he spends most of his time. "I describe LA as a large box with a diamond ring in it. Surrounding the diamond ring is bunches of styrofoam popcorn. You have to be strong enough to sift through all that popcorn and not mistake it for the diamond." He mentions the pomposity of some of his peers in the city. "There are a lot of actors who take their jobs and themselves a bit serious. I was that guy in my early 20s. But I don't know … I'm surrounded by a city that takes itself very seriously when it's really just a bunch of popcorn."  I want to know how he developed the Campbell character - particularly Campbell's voice. It is weirdly formal, a sort of clipped, preppy accent that sounds completely of its time. He picks up my tape recorder, speaking into it like a microphone. "There's a certain timbre to the voice that people just don't have any more," he says. "There was a formality … " To prepare, he watched a lot of old films. "I borrowed from my grandfather, who had that timbre." He drops his voice an octave or two. "Yes, dear," he says in Campbell's voice. It is soothing and slightly syrupy. "Dorothy, it's time to go now."  "I wanted [Pete] to have a strong presence. I'm kind of a small dude, I don't have a big presence in real life, I'm not 6ft tall, I don't have muscles, so I wanted [the voice] to be how he presented himself, how he made himself important."  Campbell wants to be important but never quite makes it. "He's desperate," Kartheiser says. "I wouldn't say he's psychotic because he feels remorse." He doesn't learn, though, I say, thinking of his serial philandering and office conniving. He keeps making the same mistakes. "Well, he's a human being. We are driven, especially males, by our wants in that moment … " He leaps up to embrace an actor I don't recognise. "Really good stuff, buddy," he says. "I don't care what anyone says, that was great work." He slaps him on the back and sits down again. "[Pete] makes these mistakes. John Slattery [who plays Roger Sterling in the show] was saying the other day how being a mature person is wanting to do something but then realising, 'Oh, that's going to destroy my life if I do that.' That's a maturity Pete doesn't have."  It is almost time for me to leave. Before I do, I suggest Campbell needs a dose of therapy. "Most definitely," he says, sighing. I wonder how he copes with challenges in his own life. "I go to therapy. Seriously." He says he has never been a party animal but hasn't always resisted other temptations (he appears to have settled down and is engaged to Alexis Bledel, who played an unhappy married woman with whom Campbell became infatuated in the fifth season of Mad Men). "I'm not a perfect human being, I have flaws and I wouldn't want to be [perfect]. Mark Twain said: 'Good judgment comes from experience. Experience comes … from bad judgment.' Thank God I have f***ed up in my life, thank God I've taken risks. Otherwise I would never be able to play a guy like Pete Campbell."  Matthew Garrahan is the FT's Los Angeles correspondent.  Copyright The Financial Times Limited 2013  (c) 2013 The Financial Times Ltd. All rights reserved.
Can there be a more incongruous sight than Don Draper intently examining an  iPhone ? Wearing a suit so sharp it could draw blood, his hair slicked back, the doyen of 1960s admen is sitting by a trailer in the shade under some trees, writing what looks like a text message. Maybe he is checking his Facebook status or uploading an Instagram photo. Whatever, it doesn't look right. He is in the wrong era, a man out of his time.