We have stabilized and electronically controlled the carrier-envelope phase (CEP) of high-power femtosecond laser pulses, generated in a grating-based chirped-pulse amplification kHz Ti: sapphire laser with two multipass amplifiers, using the direct locking technique [ Opt. Express 13, 2969 (2005)] combined with a slow feedback loop. An f-2f spectral interferometer has shown the CEP stabilities of 1.2 rad with the direct locking loop applied to the oscillator and of 180 mrad with an additional slow feedback loop, respectively. The electronic CEP modulations that can be easily realized in the direct locking loop are also demonstrated with the amplified pulses. (c) 2007 Optical Society of America.