New old stock (NOS) component supplies can be interesting if you are looking for cheap or obsolete components, but since such parts are old by definition and may have been stocked under less than ideal conditions, it is more than highly recommended to test them before usage. There is nothing worse than debugging a circuit only to discover that the problem is due to the “new” part you just inserted.

Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime
After having inherited a big batch of new old stock (NOS) single, dual and quad op-amps of unknown condition, this designer was faced with the task of testing them all. To make his life a little bit easier he first spend some time to create a simple test tool capable of checking single, dual and quad op-amps in DIL packages. Green LEDs indicate op-amps that work as expected, a voltmeter is used to display the offset voltages.

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