Abstract: A method and apparatus for automatically removing a slub from spun filament yarn and a sliver or roving of staple fibers. The sliver or roving of staple fibers are fed through a drafting apparatus to prepare a continuous bundle of staple fibers. The filament yarn is pretensioned such that a texture is temporarily substantially removed. The continuous bundle of staple fibers and the filament yarn are combined downstream of the drafting apparatus. The combined continuous bundle and the filament yarn are fed into a spinner. The spun filament yarn and staple fibers are monitored to detect imperfections of a predetermined magnitude. A first signal is generated upon detection of an imperfection of the predetermined magnitude. The feeding of the staple fibers is stopped in response to the first signal. The core yarn is clamped at a predetermined position in response to the first signal.