The 275 is an ultra low noise level, voltage pre-amplifier designed for use with low impedance single sources. Its’ input voltage noise is less than that of a 50W resistor at room temperature.

The 275 has been designed with features specifically for use with mercury cadmium telluride detectors. These include an input shorting switch to avoid damage to the detector during connection and a constant current biasing circuit which allows you to set precisely the bias current recommended by the detector manufacturer without having to select resistor value.

The unit can be supplied without bias supply for use with search coils and other unbiased low impedance sources.