  We present a 100 kHz optical parametric chirped pulse amplifier (OPCPA)
developed for strong-field attosecond physics and soft-X-ray transient
absorption experiments. The system relies on noncollinear potassium titanyl
arsenate (KTA) booster OPCPAs and is pumped by a 240 W, 1.1 ps Yb:YAG Innoslab
chirped pulse laser amplifier. Two optically synchronized infrared output beams
are simultaneously available: a 430 {\mu}J, 51 fs, carrier-envelope phase (CEP)
stable beam at 1.55 {\mu}m and an angular-dispersion-compensated, 125 {\mu}J,
73 fs beam at 3.1 {\mu}m.
