highly focus to headphones

• dac/amp & amp for headphones, speakers :
  – rme adi 2 pro fs / thx aaa 789 / geshelli erish & e2
  – fostex hpa4bl for speaker
• daily headphones & iems
  – ether flow open / dt1990 / iLoud MM
  – akg n5005 / moondrop chu 2
  – r70x / edition xx