Amp requirements

"Even a headphone amp such as the $20 FiiO E5 can produce the same 1.2 Vrms into any load from 16 ohms (about as low as headphones go) to 600 ohms (the common upper limit)."
http://nwavguy.blogspot.com/2011/09/more-power.html

"Most consider peaks of 110dB SPL sufficiently loud. Tyll measured the 300 ohm HD600 at 0.23V for 90dB so they need ten times more, or 2.3V, for 110dB. The power is (2.3 * 2.3) / 300 = 18 mW. This works for any headphone Tyll measured."
http://www.innerfidelity.com/content/nwavguys-heaphone-amp-measurement-recommendations#tbx7K8W5uVrU2YGH.99



Ether
Volts RMS required to reach 90dB SPL: 0.071 Vrms
Volts RMS required to reach 110dB SPL: 0.71 Vrms
Amplification not needed


HD 800
Volts RMS required to reach 90dB SPL: 0.242 Vrms
Volts RMS required to reach 110dB SPL: 2.42 Vrms
Amplification benefits


HE-560
Volts RMS required to reach 90dB SPL: 0.330 Vrms
Volts RMS required to reach 110dB SPL: 3.30 Vrms
Amplification benefits


LCD-2
Volts RMS required to reach 90dB SPL: 0.114 Vrms
Volts RMS required to reach 110dB SPL: 1.14 Vrms
Amplification not needed


HE-400i
Volts RMS required to reach 90dB SPL: 0.162 Vrms
Volts RMS required to reach 110dB SPL: 1.62 Vrms
Amplification benefits


HD 600
Volts RMS required to reach 90dB SPL: 0.230 Vms
Volts RMS required to reach 110dB SPL: 2.30 Vms
Amplification benefits


HE400S
Volts RMS required to reach 90dB SPL: 0.086 Vrms
Volts RMS required to reach 110dB SPL: 0.86 Vrms
Amplification not needed


DT 880 (250 ohm)
Volts RMS required to reach 90dB SPL: 0.299 Vrms
Volts RMS required to reach 110dB SPL: 2.99 Vrms
Amplification benefits


DT 880 (600 ohm)
Volts RMS required to reach 90dB SPL: 0.514 Vrms
Volts RMS required to reach 110dB SPL: 5.14 Vrms
Amplification benefits


K7XX
Volts RMS required to reach 90dB SPL: 0.206 Vrms
Volts RMS required to reach 110dB SPL: 2.06 Vrms
Amplification benefits


SRH1540
Volts RMS required to reach 90dB SPL: 0.109 Vrms
Volts RMS required to reach 110dB SPL: 1.09 Vrms
Amplification not needed


PM-3
Volts RMS required to reach 90dB SPL: 0.037 Vrms
Volts RMS required to reach 110dB SPL: 0.37 Vrms
Amplification not needed


Focal Spirit Professional
Volts RMS required to reach 90dB SPL: 0.036 Vrms
Volts RMS required to reach 110dB SPL: 0.36 Vrms
Amplification not needed


NAD VISO HP50
Volts RMS required to reach 90dB SPL: 0.037 Vrms
Volts RMS required to reach 110dB SPL: 0.37 Vrms
Amplification not needed


ATH-MSR7
Volts RMS required to reach 90dB SPL: 0.023 Vrms
Volts RMS required to reach 110dB SPL: 0.23 Vrms
Amplification not needed


Mad Dog
Volts RMS required to reach 90dB SPL: 0.208 Vrms
Volts RMS required to reach 110dB SPL: 2.08 Vrms
Amplification benefits


HE-500
Volts RMS required to reach 90dB SPL: 0.310 Vrms
Volts RMS required to reach 110dB SPL: 3.10 Vrms
Amplification benefits