My question is: can the O2 amp fully drive the Beyerdynamic T1 at typical listening volumes (i.e. without clipping etc.)? Here are some resources I've looked at to try and figure this out:

Resources:

- Measurements of Beyerdynamic T1 (impedance seems to reach a peak of 1400 ohms!):

http://www.innerfidelity.com/images/BeyerdynamicT1.pdf

- Specs of O2 JDSLabs (outputs 88 mW into 600 ohm load) [note that I'm looking at the epiphany acoustics version which has a maximum gain of 5x as opposed to 6.5x for the JDSlabs model]:

http://www.jdslabs.com/products/35/objective2-headphone-amplifier/

- Power requirements (at nominal impedance i.e. 600 ohm) calculated to reach 120 dB

(T1: 63 mW, 10 mA, 6.15 V rms):

http://www.head-fi.org/t/476345/headphone-sensitivity-power-requirements-compared

- Power requirement (taking impedance at 500 Hz i.e. 750 ohm) calculated to reach 110 dB SPL

(T1: 16.786 mW, 4.731 mA, 3.548 V):

http://www.head-fi.org/t/668238/headphones-sensitivity-impedance-required-v-i-p-amplifier-gain

Conclusion?

From the above data what I understand is that the epiphany acoustics O2 amp can supply a maximum of around 10 V into a 600 ohm load with a power of 88 mW. Also from the data supplied for the O2 amp, it appears that at larger impedances less power is supplied i.e. 613 mW into a 33 ohm load and 355 mW into a 150 ohm load. Therefore for impedances above 600 ohms the power supplied is expected to be less than 88 mW.

Therefore there is just enough power and voltage to drive the T1 to 120 dB at an impedance of 600 ohm but at certain frequencies with very high impedances (i.e. 1400 ohm) it will probably not supply enough power.

At 110 dB the O2 should easily be able to supply enough voltage and power at all frequencies.

Am I reading all this data correctly?

Edited by PTom - 2/24/14 at 3:42am