A one-man show with a kaleidoscope of roles can be an opportunity for both the actor and the audience.

So it is with "National Electric," unfortunately scheduled for only three more performances at the Source Theatre. In a 75-minute span on the stage, Robert Perring, a talented young Los Angeles-based actor, limns a dozen quick-sketch male portraits, ranging from a precious poodle-owner to 19-year-old Bronx punk to a paranoid slipping from reality.

One of th delights of the theater is to watch an actor at work, catching the subtle nuances of voice, posture and body motion that communicate the character. By changing his stance or way of sitting, or by shifting his voice to a harsh rasp, Perring quick-changes characters in short five-to-10-minute monologues.

Not everything works in "National Electric." But energy and imagination are evident even in the three or four misses among the dozen sketches. Perring himself wrote eight of them and contributed to the other four. They can be quite funny, occasionally touching and even frightening. The 19-year-old punk tells matter-of-factly how he "cleanly" slit the throat of his victim, who was snoring off a drunk. Recounting his nightmares, the paranoid begins quietly, then the tension builds as he paces and his voice rises.

It is not easy to capture a character with a revealing monologue in just a few minutes. Several come off murky and undefined, including the country-music singer having a set-to with his manager. Perring, both in his stage presence and the material, doesn't quite capture the feisty old man talking to his daughter in the old folks' home.

But more often than not, the sketches are on target. Perring is hilarious as the poodle-owner, and does a nice sketch about a young man in love once again. He smirks and smiles knowingly as a high-school smoothie who turns the tables on the teacher who reported his petting on the stairs.

With judicious employment of a cap, a cigarette or a hospital robe, Perring effectively shifts characters with few props except for some chair groupings. A darkened stage with light from a bare bulb catches the stark feeling of a monologue over the body of a young rock musician dead of a drug overdose.

Gerald Dugan, a guest professor at American University, directed the Source staging of "National Electric" and contributed to one sketch.

Perring will perform "National Electric" at 8 tonight. The two remaining performances ae scheduled for Saturday and Sunday at 5 p.m. at the Source Theatre, 1809 14th St. NW.