Noice... not the overheating bit, but the 3ch NC400 bit. Most of the commercial implementations seem to heatsink rather than fan, although given you've already assembled the chassis probably easier just to add airflow, especially if it's only problematic basically once per year. How've you found it generally, and what speakers does it feed? I've mostly of settled on either a 3ch NC500, or maybe 3x mono NC1200s for what would hopefully transpire to be near-unlimited headroom (and the last LCR amp I'd ever need), but that means no DIY obviously. I'd prefer to have the option to DIY either of those, if nothing other than for the sake of comparison with Apollon, Nord et al. For that reasons the NC400s do still appeal. That said it seems like some of the "boutique" options are pretty good value. For your 11/12ch, are you looking at NC400s or something else? Nord's nCore-MP amps seem pretty keenly priced when you consider the costs of the raw materials, plus a nice chassis and warranty.