IT HASN'T BEEN an easy year for John Neville-Andrews. Last September he took over the job of artistic producer at the Folger Theater Group, arriving just as Louis W. Scheeder, the man who had run the place for nine years, was leaving because he refused to cut the budget to suit the trustees.

Since the day last fall when Neville-Andrews, new boss, walked into the shabby Capitol Hill offices of the theater where he had once been merely one of the cast, the theater has endured a serious threat of extinction, cutbacks in staff, three sets of bad reviews, pique on the part of some of the veteran actors, the replacement of a star in the final weeks of the run, the firing of a director a week before opening night, and the prospect of raising more money than has ever been necessary before.

"It's been exactly as I expected," Neville-Andrews said. "A tough, difficult and painful year."

Since things have been looking up recently, thanks in large measure to the success of "The Comedy of Errors" (the run has been extended through July 25), which Neville-Andrews directed himself, he regards the future with optimism, based somewhat on the view that since this year was so tough, the next year will have to be an improvement. He talks like a man who's been through tough times and is rather proud to have survived them.

His office is down the street from its parent organization, the Folger Library, on the second floor of a building that is rumored to have been the mausoleum where Lincoln's body was kept before it lay in state. It is furnished with a desk and two sofas, forcing him to endure quantitites of casting-couch jokes, and a large sculpture of a mermaid stretched in front of the boarded-up fireplace. On a table by the door is a stack of plastic frames that he had planned to use to post pictures of the actors in the lobby of the theater, before he discovered the walls were made of stone.

"The staff put them in here to remind me of my folly," he said wryly.

He is full of plans for next year. This summer he will audition actors for a resident company to be in place next fall, an expensive step that Scheeder also had dreamed of. "It will help us bring a uniformity and ensemble playing to this theater," he said. "It's the right way to work for a classical theater." The company also would form the nucleus of a conservatory he would like to begin in a few years.

While Scheeder made his reputation with the modern plays he premiered at the Folger in between the Shakespeare plays it was founded to produce, under Neville-Andrews the theater will return to strictly classical fare. The next season will include "The Merchant of Venice," "All's Well That Ends Well," "She Stoops to Conquer," a medieval pageant, and a fifth play that will be either a French or British classic with an imported director.

He has revitalized the theater's advisory board, and is working to establish a women's committee of "dynamic, intelligent women" who "get lost in this city because of their husbands' positions," to help with the fund raising and special events. Another project is to set up a David Garrick Club, named after the English actor-manager of the 18th century, which would allow members to host dinner parties in the library's newly redecorated board room before a show. And reserved seating has been instituted for next year, a change from the customary queue and scramble starting a half-hour before performance.

More significantly, Neville-Andrews has made a commitment to the board of the library that the theater will become self-sustaining, a goal that will not have been attained when the box office closes for "Comedy" July 25. Although he has adhered to the budget this year, he said, a deficit will remain because the three critically unsuccessful shows failed to sell as many tickets as originally expected.

And Neville-Andrews has started talking like a producer, reeling off the star-quality names he tried to woo to the tiny Folger this year to play Prospero and his daughter Miranda in "The Tempest": Christopher and Amanda Plummer, Roy and Michelle Dotrice, Tony Perkins, Len Cariou, Brooke Shields, and Cleavon Little as Ariel.

He looks like a producer too, wearing a tie and coat regularly for perhaps the first time in his adult life. "That's the image I want for this theater," he said, with the air of someone who has perhaps been ribbed about his clothes too often. "Respectability. It gives people the impression that I know what I'm doing."

NEVILLE-ANDREWS was a surprise choice to take over from Scheeder. A 35-year-old Briton, he had worked in this country since 1972, when he arrived on tour with a zany revue that he also co-wrote called "El Grande de Coca Cola." A few years later, he fled the troop for fresher turf, and in 1977 came to the Folger to play Guildenstern in "Hamlet." Since then he has appeared in 10 Folger productions, including his well-remembered portrayal of the paralyzed artist in "Whose Life Is It Anyway?" but had no previous experience running a theater, although he assisted in the management of two theater companies in England.

By 1979 he had decided to make Washington his home: His plan then was to start his own theater. Jobbing around as an actor, director and teacher, he worked at many of the smaller professional companies like The Roundhouse and Olney, and at most of the major universities. But he was known primarily as a good actor and a developing director, not as an experienced producer or manager.

"He was very much admired for his ability as an actor," said Folger Library director O.B. Hardison. "We had an excellent manager and stage manager, and we wanted someone thoroughly conversant with the Washington scene and the theater group. He fit the profile." But Neville-Andrews was hired only after he submitted a revised budget that adhered to the $1 million level Hardison and the trustees wanted. (Scheeder had sought a $1.3 million budget.)

"He always wanted to have a theater, so the transition wasn't as difficult for him as it might have been," said Ralph Cosham--an actor now playing in "Comedy" who has not always gotten on with Neville-Andrews--"although there certainly is a different relationship than there was when we all used to go over to the Tune Inn for a few drinks after the show."

The first decisions Neville-Andrews made were to shorten the run of "Julius Caesar," which Scheeder had directed and which had gotten some scathing reviews, and to cancel plans to produce "King John," substituting "The Rover," an obscure 18th-century play that was also a critical and financial flop.

"Closing 'Julius Caesar' early showed a defeatist attitude," said Cosham, who played Brutus. "It was like admitting it was a piece of crap. The audiences were starting to come just when he closed it."

Neville-Andrews doesn't agree, but he admits freely that "The Rover" was a mistake. "It was a brave choice," he said. "I walked in the door and took a risk, and theaters should take risks. But it was a mistake to do it. The play an adaptation wasn't ready, and in retrospect I wouldn't do it again without more time. I had to let the director go and take it over myself at the last minute. I had been too busy to keep an artistic eye on it and by that time it was almost too late."

Canceling "King John" also was a mistake in the view of others who see the Folger as a treasury of rarely done Shakespeare plays. "That play hasn't been done by anyone for 40 years," said David Cromwell, another of the theater's better known players. "The Shakespeare Mafia would have flocked to see it." But both Cosham and Cromwell say that working on "Comedy" has been a pleasure and that Neville-Andrews is an excellent director.

"The Tempest" also arrived with problems. Prospero was cast only a week before rehearsals were to begin, after the most notable luminaries had turned down the part. Joseph Wiseman, at 64 a man with an eminent career behind him, took on the role. He suffers from hypoglycemia and blacked out midway through one performance, which had to be suspended. Another time he blacked out during a matinee, and eventually ended up leaving the show halfway through the eight-week run.

Cromwell, who has made a small specialty of playing Shakespearean clowns, said that the theater failed to give Wiseman appropriate living arrangements, a good director or technical excellence. "You can't expect a guy like that to work with a jerk," he said, referring to director Roger Hendricks Simon. But Cromwell lauds what he views as a change in attitude from Scheeder's administration, when "everybody just saw the theater as a stepping stone to New York. We need to serve this community, not New York. This theater is unique--it's the only place to do intimate Shakespeare in the country professionally. I left New York because I wanted to work at the Folger. John seems to be more interested in this, although when I hear talk about Brooke Shields it makes me nervous."

Neville-Andrews regularly attends productions at small theaters, looking for talent, more so than any other major producer in the Washington area. Three actors he saw in "Bent" at the Source Theater are in "A Comedy of Errors," for example, and of the cast of 22 only three were hired in New York. "I remember how many times I got the brush-off as an actor," he said. "I try to talk to anyone who calls." He tries to open the mail himself, partly to relieve the burden on an overworked secretary. He chats with any subscriber who calls with a comment or complaint, and tries to keep an open-door policy for the actors and staff as well.

The most difficult task he had to learn was raising money, he said, but it is one he must learn, particularly if he wants to keep hiring special staff like the voice coach, hairdresser and makeup specialist he got for "Comedy."

"Raising money was alien to my culture, because in England most theaters are locally supported," he said. "But I had to force myself to do it."

He has not been particularly successful yet, although he weathered a spring crisis when the trustees of the Folger, faced with a possible reduction in maintenance funds from the Park Service, proposed withdrawing their support of the theater. That was averted, and a "10-20 Club" was formed of benefactors willing to donate $10,000 toward maintenance costs and guarantee another $20,000 toward any deficit at the end of the next season.

Looking back at his first year in the boss' chair, Neville-Andrews is glad it's over. "I wanted to come in and make everything right, and instead it seemed like everything I did went wrong," he said. "It was psychologically painful. There were heated arguments, and I want this theater to be a peaceful place. But I think 'Comedy of Errors' is a turning point."