The analyser is fully automatic once set up. You can sellect the load required, set the maximum test output and then perform the test. It will first check the DC offset (set in the menu). it will then in 100 level steps run the amplifier up to its maximum output (set in the menu) and check for symetrical output as it runs the test. If it passes without error in the amplifier, it will display the output power in RMS, peak and P to P output as wel as the THD. Fully controlled by a single PIC micro and programmed with the four soft function buttons and encoder. As it stands, it can measure up to 200 watts and with an external load, up the 1Kw. The project hardware is finished, but a little more programming to do. I have also writen some software in Visual Basic to display all parameters and view the test via RS232 onto a PC.