This custom designed amplifier was created and manufactured by Lafayette Instrument Company and was designed specifically for Actimetrics Freeze Frame and other operant conditioning systems. The input is compatible with the stereo output of the control computer. The left/right computer outputs are split to form four balanced amplifier outputs for each of four fear conditioning test chambers. In other audio stimulus applications, one could also support two independent speakers in two test chambers with this device, (Outputs 1 and 2 as left channel. Outputs 3 and 4 as right channel).