Ok, I have recently heard a bunch of Trainwreck clone amps and they are seriously good sounding. The usual arguments about these amps center on whether Dumbles or Trainwrecks should really be worth that kind of huge dough. I have a different question: was there any technical innovation behind Traniwreck or Dumble that made them such landmark amps that were destined to appreciate? I don't mean innovation as in they sound good, but in terms of circuit design. Did Dumble or Fischer do anything to revolutionize the way people built amps that was not done before? My inquiring mind needs to know (Perhaps the answer lies buried in the thousands of archived posts on the topic, but as most of us don't have 8 hours to review each thread about trainwreck or dumble I ask the question here).