We report on a high power diode-pumped laser using multiple bulk Yb:KY(WO(4))(2) (KYW) crystals in a resonator optimised for this operation. From a dual-crystal resonator we obtain more than 24 W of cw-power in a TEM(00) mode limited by the available pump power. We also present results for semiconductor saturable absorber mirror (SESAM) mode-locking in the soliton as well as positive dispersion regime with average output powers of 14.6 W and 17 W respectively.