The Model 601-1CM112 is originally designed for use with a hydrophone in which the transducer was 80 pF. CAL loss was 3 dB nominally, CAL attenuator is 20 dB, and preamplifier gain is 23 dB. It provides high performance, including gain stability phase stability, and noise over the 20Hz to 100 kHz band while providing a balanced line driving capability.