**power measurements**

Yup. That is the basic easy way. Besure that the device (DVM, whatever) is accurate at the frequency you are measureing. (Not all DVMs are accurate over the whole audio range) If you are using an oscilloscope note that you must divide the peak-to-peak voltage by 2.83 to get the RMS voltage. To save a step you can square the RMS voltage and divide that answer by 8 (ohms) to get power in watts. Then you can use different values of dummy loads to see if the amp puts out more power at different load resistances. Your source sould be a sine wave with little distortion. Ideally, your dummy load resister should have no or very little inductance. However, at low audio frequencies a wire wound resistor will probably not have enough inductance to mess up your measurements.

If you are testing a commercial amp be aware that it might not put out full power for very long. So get your set up set up, turn the amp up, take your measurement, turn the amp back down and then do your math. (This is the voice of BITTER experience!)