- Apr 10, 2015
It all began when I spent a ton of money on a ‘Great’ headphone amplifier. What was included in this supposedly hi-fi headphone amplifier was a single class-AB IC with 2 to 3 coupling capacitors, an OPamp with four transistors working as a buffer. Now its manual said that the headphone amplifier was capable to driving Sennheiser HD800 or equivalent headphone. That’s totally absurd! For example, HD800’s maximum long lasting input power is 500mW. To reach that output (of 500mW), your amplifier needed to deliver 35 Vpp (peak to peak voltage) for HD800! That means you needed an amplifier with at least ±18V working voltage (or a single DC voltage above 36V). Unfortunately, this is a common problem with high impedance headphones (Sennheiser HD800, or Beyerdynamic T1... etc.).