A mode locked fiber laser based on Yb-doped large mode area photonic crystal fiber operating in the all-normal dispersion regime is experimentally studied. The eighteen cores of the gain fiber are arranged in array-type geometry with an equivalent mode diameter of about 52 μm. A sigma laser cavity is used without using any elements for dispersion compensation. Reliable self-starting mode-locking is achieved using a fast semiconductor saturable absorber mirror. The laser directly produces 4.92 ps chirped pulses at a 44.68 MHz repetition rate for an average power of 3.3 W corresponding to a pulse energy of 74 nJ. The pulses are compressed to 780 fs with a grating pair outside the cavity.