You could measure the point where the overall gain of the headphone amp section is 1x, but i don't see the point. Keep it on low gain and put the volume around 2.
from Fall 2002, this was the 3rd amp i had built, which became the first Gilmore V1. the CDP was a cheap trendy Sony SACD player at that time. dont have pics of the first 2 amps I had built. they were both META42 variants.
didn't really buy it, but I do pay rent, and my heating broke a few weeks ago. New system installed is "Mr. Slim"
Mitsubishi Electric - Mr. Slim Split-ductless
There would be a small benefit in stereo separation, er i mean "music behind your head" going 4 wires to the plug... beyond that it's all voodoo
Something JH/UE could do is replace the cheap tantalum cap in the crossover with niobium oxide caps costing a few cents more.