June 2021: The QA451 is on backorder, with new order arrival TBD. The issue, as with our other products, is the silicon shortage discussed here.
The QA451 is the replacement product for the QA450. The QA451 is designed for high-speed testing of amplifiers. If you are testing at the module level (with modules designed for single supply operation), the QA451 allows the on/off control and current measurement of the supply rail. If you are testing finished amplifiers (eg amplifiers that plug into a wall), then the QA451's programmable loads can enable fast automated testing when combined with the QA401 audio analyzer.
Product Data Sheet
Introducing the QA451
Using the QA451 with External Loads