As soon as I get my hands on some, I'll be able to transition from "picking your brains" mode to "contributing with new information" mode.
That said, looking at pictures of the crossovers posted in one of the threads (viewtopic.php?f=15&t=7773&p=86233&hilit=alIII#p86233), I see lots of potential for some improvements. I say potential, because Mr. Carver always seems to do the impossible, and I wouldn't be surprised to for him to take advantage of a property of what would normally be considered a design flaw.
Here are some of this things I see (easiest first, hardest last):
* Replace electrolytic caps with metalized polypropolene or other
* Replace wire wound resistors with non-inductive resistors
* Add high quality bypass caps to existing caps
* Reposition inductors and change orientation to prevent magnetic interactions.
* Replace inductors with high quality Solen and Erse inductors. Going this route would also mean matching DCR's and likely result in adding non-inductive resistors in series with the replacements.
* Replace all caps with biased capacitor pairs
Anything beyond minor surgery would likely be best done separate from the stock crossover. I usually like to retain the stock crossover completely intact, and build a separate network. This also allows me to make side by side measurements and listening comparisons. Considering what these ribbons are cabable of I think a completely redone network (biased caps, new inductors properly arranged, non-inductive resistors) might be in order.
Has anybody been down this road and what were your results like?
JBL XPL-200A / XPL-140A / L-46 / 4344 mk2 clones in progress /
Pioneer SA-9500II / RT-707 / Technics SL-1800 II TT
SAE 4400 Active Crossover / Audionics CC2
Yamaha RX-V863 AV Receiver / Denon TU-380RD
Panasonic BDP 50 Blu Ray / Toshiba HD-A35 HD DVD