Ambika Voltage Test Failure

I’ve finished an Ambika build and am experiencing problems in the testing phase. I’ve checked continuity between all test points and everything looks good there. However, when testing voltages at the 4 non-ground test points, I get values that are about 2-3V too low for all points except the “blue” point, which reads correctly at 8V. Also, when I connect my power supply to the Ambika, I hear a humming sound that I can’t pinpoint the location of it seems like the whole wiring system in the room just takes on this omnipresent hum. I’ve tested the power supply and it’s delivering about 10.98V AC. A little high, I know, but should at least work for testing, right? What might be causing only the blue point to read a correct voltage. The only solder joints I’m currently unsure about are for the “gain of the final mixing stage” resister, which is a functioning 4.7k. If these solder joints were bad, would they cause the issues I’m seeing?

IC11 is the wrong way round!

Oh dear, I feel stupid. Thanks for your good eye!

Turned the chip around and all voltages read correctly now. Thanks, cj55.