The Amp boards arrived Saturday, unfortunately, I was just leaving for work so they'd have to wait. Everything looked OK on them.
Initial power up test was done with both LME49990 in place but only one LME49600 mounted on each channel [PSU used was a modified "The Wire" unit meant for testing the A/B Power Amp at +/-25Vdc, now set at +/-15Vdc. It was getting quite hot as it was dropping 10V per rail]. That went Ok, so the rest of the 49600 were put in place and powered up once more... Again, everything OK.
Left channel: 27mV
Right channet: 8mV
Foam board speakers are progressing, and will be ordering a heatsink this week also.
Been a little bit worried about the higher offset value on the left channel, though it's not at a bad level overall. Once the amp has been on awhile, it appears to settle at 25.9 mV.
Made a quick SE input>volume pot AC coupled...