We present the amplifying features of the copper bromide brightness amplifier excited by a capacitively coupled longitudinal discharge. The dependences of the amplified spontaneous emission (ASE) power, gain, and the sensitivity of the brightness amplifier on the pulse repetition frequency (PRF) of the excitation have been obtained. The PRF of excitation varied from 12 to 24 kHz. At PRF 24 kHz, the output power was 2.1 W, pulse duration was 30 ns that is lower than for a copper bromide brightness amplifier with the typical excitation pulses. The small-signal gain reaches 0.25  cm^−  1, which is commensurate for a copper atom active media with the typical excitation charge. The sensitivity of the investigated amplifier is 0.01% of ASE power in the studied PRF range.