I have a provisional patent that I am willing to donate to Diy. In cursory explanation certain amplifier classes excel at different nuances, my little idea is to contain in one chassis a class a, a/b, d, tripath(TM) and a class g amp, with a circuit comparing the input to the accuracy of the output stage and simultaneously selecting the most accurate, distortion free, and efficient amplifier matching the waveform of the input (it may change between amplification methods several hundred times per second). In addition, the user could override and select a particular amplification method if desired. I am working on the prototype, and would love any feedback (pun intended) from the group. Also, if anyone knows if this has already been done, then for God sakes let me know so I can just buy the amp (although that would be less fun).