SOMETIMES when Phil Cornwell laughs – and readers, he laughs a lot – you hear the ghost of all the other people he has ever been.

It first happens when Cornwell is discussing the dangers of improv in comedy. "Because you can't just go: 'Oh I'll improvise it all," he is saying. "I've tried that before and it doesn't work. It doesn't bloody work. I've tried that before and failed miserably."

To be honest, I'm not really paying attention to the words, it's the laughter that accompanies it that has my attention. I keep thinking: “Is that ...? Is he doing ...? That sounds awfully like ... Jack Nicholson.

The next time it happens I can't help but flashing on Cornwell's turn as the DJ and (supposedly) recovering addict Dave Clifton in the 2013 Alan Partridge movie Alpha Papa, a character laughing his way towards a nervous breakdown.

And that's when it hits me. Even Phil Cornwell's laughter is performative.

Cornwell, comedian, actor, impressionist, star of the fondly-remembered (by some of us at least) Stella Street, one of the voices of Spitting Image, the voice of Murdoc in Damon Albarn's cartoon band Gorillaz, and, for those who were watching kids' telly at the end of the 1980s, the voice of Gilbert the Alien in Get Fresh, is coming to Edinburgh.

In fact, this is his first time at the Fringe for nine years. Was it something we said? "Oh yeah, I took umbrage,” he says. "No, no, I just haven't had anything presentable to do. You've got to have a show. That helps, don't it? The last time I did a set of impressions which was great, but this time it's a little bit different. More character-based. A different kind of animal really."

He's been coming to Edinburgh since 1983. Good times, bad times. That first year he was doing "an awful production of Tartuffe by Moliere. It was called Rock Tartuffe." He pauses to let me imagine how terrible that sounds. "It was in a venue called The Hole in the Ground. It's not still there, is it?

"Emma Thompson was on just after us, doing her one-woman show, if memory serves.”

Was it a case of first time, worst time, Phil? "I don't know. I think '89 might have been the worst. In terms of quitting halfway through. 'This isn't happening. Let's go home.'

"Me and my mate had written this very funny thing. Well, we thought it was funny. But there weren't enough punters and it got to the point where we thought: 'Come on, let's withdraw.'"

There have been plenty of good years in Edinburgh too. He's hoping this might be one of them. His new show is called Alackadaddy, a one-man show telling the story of Robert Lemon Alackadaddy who, Cornwell says, is "an alky but in glorious denial. He hasn't got to the realisation that he actually is one. So, he's happily carrying on.

"It's quite dark," Cornwell admits. "It's not everyone's cup of tea. But those who get it are very, very encouraging, and enthusiastic and Edinburgh's the perfect place for it."

That darkness, I say. I have to ask. Were you drawing on personal experience? "Well, yeah, it's loosely based on experiences in my misspent youth, drinking and carousing, that kind of thing, and thinking how wonderful it was at the time and then realising now what a load of bollocks it all is. How it doesn't actually help.

"The past is done,” he adds. “And you can't do anything about that. It's all valid. It's all character-forming. Well, it wasn't at the time."

And, the thing is, he points out, Alackadaddy isn't him. "It's based on people I know from the past, an amalgam of people I've come across in my life. I'm not really like him. There are similarities. I've had my moments. Not for a long time; 23 years." He starts laughing again.

Cornwell wrote the show three years ago. He left it for a while and then thought he really needed to get up on stage and perform it. "Because it takes a lot of balls to actually do it. I wrote the thing and then the next stage is; 'Are you going to go and do it?' That's the harder bit.

"And I figured; 'Get up and do it while you still can. Because I do think of people I used to know, contemporaries of mine, who are no longer here. They can't do it anymore ... And nor would they want to where they are, God rest their souls"

Maybe, he's thinking of someone like the comedian Jeremy Hardy. He talks fondly of hosting the early nights of the Jongleurs comedy club, when Hardy and Paul Merton – then still called Paul Martin – were taking their first steps in comedy.

In many ways, at 61, Cornwell's career covers the story of modern comedy. From Essex originally, he did his first stand-up at the age of 16 in Canvey Island. "I think my sister was the only one who clapped. It was quite embarrassing. I was doing lifted material from Mike Yarwood. Impressions, because I could do them. They were pretty good."

By the age of 19 he was performing in a strip club in Bethnal Green, in the intervals between the acts to an audience who weren't there for the comedy. "They didn't want to see me up there doing Tommy Cooper."

Soon, though, he was on the emerging alternative comedy circuit and then TV started calling.

"I always did it as a means to an end,” he says. “That was the thing. I wanted to be an actor. I didn't get any work as an actor when I left drama school, so I thought: 'I'll write an act and go and do it.' I was able to empower myself a little bit. I had to. It's so hard."

His vocal talents were always in demand. In Stella Street, his very funny, criminally obscure, two-hander with Scottish actor and impressionist John Sessions which ran between 1997 and 2001, Cornwell gave us his Michael Caine, Mick Jagger (a glorious, strutting peacock), David Bowie and, yes, Jack Nicholson. The conceit was they all lived in the titular street. Jagger and Keith Richards (as played by Sessions) ran the corner shop. It was a lovely and loving skit on celebrity and domesticity.

Who, I ask him, would live in Stella Street now? "I don't know. I don't even know who the new people are. Who are these young people? You'd have Matthew McConaughey there. I do him in my show a little bit. So, someone like him would probably be there because he's quite current ... Ish. I don't know. They might all still be there. That's the other thing."

It was always a cult show but one Stella Street fan was Blur's Damon Albarn. That led to Cornwell getting the gig of voicing Murdoc, one of the cartoon band members of Gorillaz. "He ended up being Keith Richard basically."

Hmm, is John Sessions still speaking to you? "We don't have exclusive rights. He does a good Jagger as well." He laughs. "I think mine might be better though."

I was very disappointed, I tell Cornwell, that when Gorillaz were last in Glasgow he didn't turn up on stage at any point. "Oh my God, that doesn't happen. It did happen years ago when they started. I used to be at the side of the stage."

At 61, he says his work-life balance is pretty good. He has five kids who range in age from 20 to 11 months. Not bad going given that he didn't become a father until he was 40. "I started late, and I've certainly made up for lost time."

The day before we talk, I tell him, I was in Asda and I noticed that Paul Whitehouse and Bob Mortimer have written a book based on their BBC2 fishing series. Does he not have a hobby that he could turn into a mid-evening BBC2 bucolic documentary? "That was such a good idea. I love those two very much. What a great idea," he says before addressing the question fully. "Hobby? Well, is running a hobby? I've done that every day for nearly seven years now. Every day since September 12, 2012.

"If you're not running every day there's always a loophole. I thought if I go every day then I have to go every day. And now I don't even think about it. No matter how I feel, I go for a run. It's insane."

And then he adds. "I don't think it's good telly, though."

This time he doesn't sound like anyone but himself.

Phil Cornwell: Alackadaddy is on at Underbelly, Bristo Square, 4.15pm until August 26. For tickets visit www.edfringe.com

Career High

It’s got to be selling the Tardis as a character in Doctor Who. I played the Stallholder in an episode called The Fires of Pompei, with David Tennant, shot on an amazing set in Rome.

Career Low

Performing at the Tilbury Railwaymen’s club back in ’77. I was 20 years old. There were about four people in the audience. My act was met with complete silence. Hey hi.

Favourite Comedian

George Carlin. He had this real acerbic New York edge. He had balls.

Favourite Film

O Lucky Man. Lindsay Anderson’s weird odyssey involving Malcolm McDowell as a travelling salesman who goes on an amazing journey through the upper reaches and underbelly of society. It had a profound effect on me. After watching it I decided I wanted to be an actor.

Last book read

Scott of the Antarctic by David Crane. A sensitive and moving tribute to the tragic polar explorer. The end is beautiful as the three men, Bowers, Scott and Wilson, come to terms with their inevitable death in a tent on the vast Barrier of the Antarctic.

Best and worst trait

My best trait maybe is the discipline. I have to go out running every day. Have done for nearly seven years now. My worst trait is probably a slight tendency to be impatient.

Best advice received

Try and listen to people when they’re speaking. Allow them the space to be themselves. I may not always succeed.

Biggest influence

In life it’s probably Eckhart Tolle, after reading his seminal work , The Power of Now. My friend Kevin Eldon bought me a copy of it when I was at the Fringe in 2010. It took me seven years to actually read it. Talk about the Power of Now!

Ideal dinner party guests

Madison Bumgarner, ace pitcher with my beloved San Francisco Giants, Jack Nicholson, Frances MacDormand and Jack Kerouac. Now there’s a line-up for you. They’d have to bring their own food, I’m not the world’s best cook.