Testing and safety
Testing and fault-finding
Testing power amplifiers for correct operation is relatively easy; faultfinding them when something is wrong is not. I have been professionally engaged with power amplifiers for a long time, and I must admit I still sometimes find it to be a difficult and frustrating business.
There are several reasons for this. First, almost all small-signal audio stages are IC-based, so the only part of the circuit likely to fail can be swiftly replaced, so long as the IC is socketed. A power amplifier is the only place where you are likely to encounter a large number of components all in one big negative feedback loop. The failure of any components may (if you are lucky) simply jam the amplifier output hard ...