Rich, "simpler" was an over-simplification on my part. Andrew worked on that thing for 2 years. I'm sure others were helping him with it. And how many years before that were others working on it like Tom Cumberland? At least 8 or 10. So there's lots of history with it and one of the reasons I really dig Ian is because he had the intestinal fortitude and vision to know what is the right thing to do.

I'm not sure the ADAs use a chip other than for protection; I have not looked closely at the amp channel boards. I don't know where technology is today with regard to class D ICs. I know when I was involved with it in 2002, we had to build high current and high voltage channels with class D amps from scratch and it was a total nightmare because we couldn't achieve the required stability and EMC.

When I look at the guts of the ADA, it's simple in that you can readily see where everything is and it's easy to access. It should be straight-forward to replace the rectifier/filter board for example when it comes time to re-cap because it's readily accessible and has what looks like four screws. Ditto with the amp channel boards.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated