I built the mainline, checked all the solder joints, passed the resistance and voltage checks with flying colors, been playing music through it for a day now using my only headphone at the moment (Mr. Speakers Ether C ) and it sounds pretty good.
However, I noticed 2 potential issues (not sure if I should be at all concerned about them):
1) The impedance switch doesn't seem to be doing anything when switching from low to high as far as volume is concerned. On my other amp (Schiit Magni 2U) it's a major difference. Not sure if this is a normal experience on low impedance cans.
2) When plugged into the Unbalanced output and switching to Balanced, I still hear all the music, just at a slightly lower volume. This is a bit different than other amps that turned off one output completely when switching.
Just want to confirm that this is normal.