We report a novel type of active fiber – tapered double clad fiber suitable for pumping by low brightness sources with large beam parameter product of 50÷300 mm×mrad. Ytterbium double clad all-silica fiber (core/1^st clad/2^nd clad diameters 27/834/890 μm, NA_core=0.11, NA_clad=0.21), tapered down by a factor 4.8 for a length of 10.5 m was drawn from a preform fabricated by plasma chemical technologies. At a moderate Yb-ion concentration and 1:31 core/cladding ratio, the tapered double clad fiber demonstrates 0.9 dB/m pump absorption at 976 nm and excellent lasing slope efficiency. An ytterbium fiber laser with 84 W of output power and 92% slope efficiency, a 74 W superfluorescent source with 85% slope efficiency and amplifiers operating both in CW and pulsed regimes have been realized. All devices demonstrated robust single mode operation with a beam quality factor of M^2=1.07.