In a small bowl, stir together sweet & sour sauce, orange juice and the tapioca. Place chicken in slow cooker bowl and pour orange juice mixture over top. Cover and cook on HIGH for 3 hours or LOW for 5 hours.
Using a slotted spoon, remove chicken to a serving platter and keep warm. Stir salt into orange sauce. Pour sauce into a gravy boat; set aside and keep warm.
Prepare angel hair pasta according to package directions. Drain, return to pot and stir in 1/2 cup orange sauce. Serve chicken with pasta and remaining sauce.