The NATIONAL RESEARCH COUNCIL CANADA has a requirement for a lock-in amplifier. Lock-in amplification is a technique that involves modulating a probe signal at a specific frequency and then demodulating the measured signal. It is a critical technique for amplification of small signals, especially when there is also unwanted noise in the measured signal. The objective is to enable the read-out of small signals at high frequencies using the lock-in amplifier technique. The system must operate reliably and consistently under experimental conditions.