In your FIRST and LAST picture, your RED wire going through both terminals of the large tube is going to 12U of the board, which is your negative rail. That red wire is supposed to go to 13U.
See my first attached photo that I snapped from the Completed Crack OTL Headphone Amp on page 46 of the official build PDF. On this snap, I put blue arrows to the wire I'm talking about. This is the correct way it should be. That red wire looks like it's going to 12U instead in YOUR photo.
For complete directions, please see page "41" of the official crack build PDF as well (my second picture)
DISCLAIMER: I did not check over your entire circuit. This is just what stood out to me when I glanced over it.