Low noise pre-amplifiers

The SR560 is a high-performance, low-noise preamplifier that is ideal for a wide variety of applications including low-temperature measurements, optical detection, and audio engineering.

The SR570 is a low-noise current preamplifier capable of current gains as large as 1 pA/V. High gain and bandwidth, low noise, and many convenient features make the SR570 ideal for a variety of photonic, low temperature and other measurements.

The SR550 voltage pre-amplifier is designed to work with any SRS lock-in amplifier. Pre-amplifiers provide gain close to the experimental detector before the signal-to-noise ratio is permanently degraded by cable capacitance and pickup. The preamplifier minimises noise and pickup in the connecting lines and reduces measurement time in noise-limited experiments.

The SR551 high impedance pre-amplifier works with SRS lock-in amplifiers to measure voltages from sources with moderate to high source impedance. The preamplifier is designed for source impedances of up to giga-ohms with little error from resistive loading, due to its exceptionally high 1 TΩ input impedance. The SR551 operates with a fixed voltage gain of ×10, amplifying signals from DC to 1 MHz.

The SR552 voltage pre-amplifier is designed to work with SRS lock-in amplifiers, providing gain where it is needed most—right at the experiment. The preamplifier minimises noise and pickup in the connecting lines and can reduce measurement time in noise-limited experiments.

The SR554 is a low-noise, transformer-coupled preamplifier optimised for source impedances between 0.05 Ω and 1 kΩ. With an input noise of only 0.1 nV/√Hz, the SR554 can be used in a wide range of low-noise applications. It is the ideal pre-amplifier for low-temperature synchronous detection applications where isolation between the experimental sample and the lock-in amplifier is critical.

The SR555 is a low-noise, high-bandwidth, fixed-gain current (trans-impedance) amplifier designed to work with SRS lock-in amplifiers. Current amplifiers provide gain close to the experimental detector, allowing the user to minimise input cable length and its corresponding input capacitance. The SR555 minimises noise and pickup before they permanently degrade the signal-to-noise ratio, reducing measurement time in noise-limited experiments.

The SR556 is a low-noise, high-bandwidth, fixed-gain current (trans-impedance) amplifier designed to work with SRS lock-in amplifiers. Current amplifiers provide gain close to the experimental detector, allowing the user to minimise input cable length and its corresponding input capacitance. The SR556 minimises noise and pickup before they permanently degrade the signal-to-noise ratio, reducing measurement time in noise-limited experiments.

The model SR445A 350 MHz pre-amplifier contains four wide-bandwidth, DC-coupled amplifiers, each with a gain of 5. The four channels may be used independently or cascaded to provide a total gain of up to 625. The fast rise time, low noise, and excellent DC accuracy of the SR445A make it an ideal instrument for amplifying the outputs of fast photomultiplier tubes and photodiodes.

The model SR240A 350 MHz pre-amplifier is a 4-channel, DC-coupled instrument with a gain of 5 per channel. The amplifiers can be used independently or cascaded to provide gains of 5, 25, 125 or 625. The fast rise time, low noise, and DC accuracy of the SR240A make it the ideal instrument for use with photomultiplier tubes and photodiodes.