D220 Pro from the inside.

[thumb5]

I dug up this thread from 2017 that refers to a patent application for the ADH technology in the Expert Pro.  The patent application includes this outline schematic for the ADH circuit:

   

The PCB we're looking at corresponds to two instances (one per stereo channel) of what's inside the box labelled 19 in the diagram.  It seems reasonable to infer that:

• the drivers 21A-D are the blocks along the top of the PCB each having an IC and a couple of transistors(?)
  
• the auto-transformers 25A-C are the large square black components each with 12 leads
  
• the inductors 32A-B are the small square black components (blue/grey on the 140) along the bottom of the PCB
  

like so:

   

I'd be tempted to guess that the remaining pairs of inductors on the 250 ADH board might be 44A, which is part of the new damping network introduced with the Pro ADH upgrade, but that doesn't make sense because they're missing from the 140 Pro board.  That being the case, maybe these inductors are also part of 32A-B and 44A is elsewhere for both the 250 and 140.