Hey Dryw, 200Hz shelving is only 1 cap and the 3rd pin up on the front deck of the LF Grayhill. See the highlighted track and pads in the attached screenshot. I would reflow those 2 pads.
Thanks so much, Jeff.
I reflowed the pads in question to no avail. As I continue to test with a simple DAW analyzer, I'm noticing that the 200hz shelf (while not affecting 200) IS affecting something around 50hz or lower, but only in shelf mode. Peak works great.
This is making me think a cap mix-up may have occurred... Is this a possibility for the behavior I am describing? If so, can you advise me on which caps to desolder and check? I'd check 'em all, but I don't want to risk damage to the components or PCB with that much desoldering.