Higher-performance sensors are becoming increasingly important to modern battlefield systems. Sensors ranging from sonobuoys to radiation detectors are critical, leading-edge components of C4ISR systems. Better sensor systems enable earlier threat detection and more effective countermeasures. Military systems employ a wide range of sensors – nuclear, biological, and chemical sensing, infrared, electro-optical, laser, radar, and acoustical – that all have one aspect in common: the requirement for ultra-low-noise signal chains to produce the best possible sensor signal. Less-than-optimal front-end amplification means C4ISR clients receive inadequate information and are not able to make effective, real-time decisions. This paper describes techniques to employ to create the lowest-noise, most effect front-end amplification for sensor signal chains. Advanced lithography design and fab process techniques enable the creation of discrete components uniquely capable of performing the critical initial amplification of sensor signals. Integrated circuits contain a wide range of components and can include specialized design features that preclude design optimization for low noise. As this paper documents, ultra-low-noise discrete components added to an IC-based circuit will produce the lowest-noise signal chain. Though this paper focuses on the LSK489 dual monolithic Nchannel JFET, many other Linear Systems parts -- including the LSK389, LSK170 and LSK189 -- also are excellent sensor system components. Linear Systems is the world leader in ultra-low-noise monolithic dual JFETs and other front-end discrete components key to high-performance sensing systems. For over three decades, Linear Systems has led the development of this class of devices, and it continues to advance their design and introduce new sensor-specific parts.