NEW YORK — Outside Studio 6B at 30 Rockefeller Plaza, the once and future home of "The Tonight Show," the smell of fresh paint and sawdust fills the air. Visitors to one of the last tapings of "Late Night With Jimmy Fallon" are led up a back staircase by an NBC page, winding carefully past dusty drop cloths and dumpsters piled with construction waste.


Jimmy Fallon: A Feb. 16 article about new "Tonight Show" host Jimmy Fallon said that the program was returning to the same NBC New York studio where it resided for its first 15 years before Johnny Carson took the show to Burbank. For the show's first three years, when it was hosted by Steve Allen, it originated out of the Hudson Theatre in New York. Under Jack Paar and then Carson, it was produced at 30 Rockefeller Plaza, where it resided until 1972.

It's just a matter of days until the launch of "The Tonight Show Starring Jimmy Fallon," and if NBC's hive-like headquarters aren't quite ready, Fallon most definitely is.

"Let's do it! We're all just ready to unleash," he says in his office, a big-for-New York space decorated with dark wood and pressed tin ceilings. After nearly a year of anticipation and a months-long publicity blitz, the comedian is eager to get started on his new gig Monday night. "Everyone here's so pumped and excited."

"Excited" is a word that comes up frequently (nearly two dozen times, by this reporter's count) in conversation with Fallon, who seems to lack the darker edges so common in his profession. At 39, Fallon, dressed in a plaid shirt and gray khakis, seems younger. He is enthusiastic bordering on hyperactive, bouncing from topic to topic and speaking in near-constant hyperbole.

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One minute he's showing off his stained-glass guitar ("the best guitar in the history of the world"), the next he's scrolling through his phone to share pictures of his beaming daughter, Winnie, welcomed in July by Fallon and his wife, film producer Nancy Juvonen ("the coolest thing in the whole wide world").

This optimistic energy is sure to come in handy at "Tonight," where he will become just the sixth host in the 60-year history of the venerable franchise. Particularly after the acrimonious Late Night War of 2010, all eyes will be on Fallon to see if his tenure is more successful. He remained studiously neutral throughout the debacle that ended with Conan O'Brien's departure from "Tonight" after just seven months, and despite what some have seen as passive-aggressive griping by Leno, the handover this time around has been handled gracefully.

"Jay's been totally supportive," says Fallon, fresh off a visit to Burbank for his last guest appearance on Leno's show. "We're friends, as much as we can be living on different coasts. He calls me every couple weeks, just to check in, like, 'Hey, hanging in there, buddy?'"

When Leno signed off on Feb. 6, he was still the top-rated host in late-night television, a position he'd maintained steadily since the mid-'90s (except during his ill-fated move to 10 p.m.). And while "Tonight" remains the marquee brand, the competition for eyeballs is fiercer than ever. At last count there are at least 13 other cable, network and syndicated late-night talk shows on the air, including "Jimmy Kimmel Live," "The Colbert Report" and "Conan."

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Fallon at least left "Late Night" with a bang: His Feb. 7 swan song, in which he performed a sweet rendition of the Band's classic anthem "The Weight" alongside the Muppets, drew the highest ratings the show has seen since David Letterman signed off in 1993.

And the comedian is determined to maintain a healthy attitude in the face of inevitable scrutiny. "I'm sure the ratings will be big for the first week after the Olympics," he says, "and then they'll go down and people will say, 'Fallon lost 40% of this viewers, this is terrible.' I'm preparing myself for that roller coaster. Don't believe the good stuff, and don't believe the bad stuff."

Growing into it

When Fallon made his "Late Night" debut, few if any could have predicted he'd ascend to the "Tonight" throne in just under five years. O'Brien, his predecessor, had just been promoted to 11:35 after 16 years and a protracted, five-year transition of power from Leno.

At the time, Fallon, a former breakout star on "Saturday Night Live," where he co-anchored "Weekend Update" with Tina Fey and played memorable characters such as obnoxious IT guy Nick Burns, was rebounding from a lackluster attempt at a film career, starring in the flops "Taxi" and "Fever Pitch." (If he hadn't been tapped by producer Lorne Michaels to take over "Late Night," Fallon figures he'd be starring in independent movies "if I was lucky" or be a content stay-at-home dad.)

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At first, it was far from obvious that Fallon was cut out for late-night TV, either. His premiere garnered mixed reviews, with his nervous monologue and uncertain interviewing skills drawing nearly unanimous criticism.