Good morning all.
I had fun making an estimate of the power requirements of different headphones for amplification reduced to a standard load of 40 Ohm.
I started on the example of the Odin Thridi on the assumption that an amplifier delivering
1 Watt (1000 mW) on 40 Ohm was largely sufficient (and optimal) to drive this planar headphones of effective sensitivity of 97.6 dB / 1 mW (43 Ohm) (at the Russian RAA measurement site).
What about other headphones more or less demanding in power for the amplifier (for a load brought back to standard 40 Ohm)?
For the
Odin Thridi (43 Ohm, 97.6 dB / 1mW) (taken as reference), it would take an amplifier delivering at least
1 Watt (1000 mW) on 40 Ohm, to be optimal at the amplification.
For the
Thror (39 Ohm, 95.3 dB / 1mW), it would then require an amplifier delivering at least
1.5 Watt on 40 Ohm.
For the
Vali (45 Ohm, 100.4 dB / 1mW), it would then require an amplifier delivering at least
0.5 Watt on 40 Ohm.
For the
Magni (33 Ohm, 103.2 dB / 1mW), it would then require an amplifier delivering at least
0.2 Watt on 40 Ohm.
For the
Utopia (125 Ohm, 104.7 dB / 1mW), it would then require an amplifier delivering at least
0.5 Watt on 40 Ohm.
For the
HD-800 S (443 Ohm, 101.6 dB / 1mW), it would then require an amplifier delivering at least
4 Watt on 40 Ohm.
For the
LCD3-F (111 Ohm, 95.8 dB / 1mW), it would then require an amplifier delivering at least
3 Watt on 40 Ohm.
For the
HE-1000 V2 (35 Ohm, 86.9 dB / 1mW), it would then require an amplifier delivering at least
9.5 Watt on 40 Ohm.
For the
Abyss (45 Ohm, 83.5 dB / 1mW), it would then require an amplifier delivering at least
27 Watt on 40 Ohm.
For the
Susvara (62.5 Ohm, 80.6 dB / 1mW), it would then be an amplifier delivering at least
73 Watt! on 40 Ohm.
For the
HE-6 SE (65 Ohm, 79.2 dB / 1mW), you would need an amplifier delivering at least
105 Watt! on 40 Ohm.
For the
HE-6 (44 Ohm, 74 dB / 1mW), it would then be an amplifier delivering at least
230 Watt! on 40 Ohm.
Good, if you find the initial hypothesis too high concerning the amplification "necessary" to drive optimally an Odin Thridi headphones (or an Odin mk2), and that would be that of 1 Watt for the power of the amplifier "necessary" on a standard load of 40 Ohm, and well, IMHO,
it is quite possible to divide this "need for amplification" by a factor 3: we would then get this new table with optimal amplifications "necessary" much more modest (and realistic?):
For the
Odin Thridi (43 Ohm, 97.6 dB / 1mW) (taken as reference), it would take an amplifier delivering at least
0.33 Watt (330 mW) on 40 Ohm, to be optimal at the amplification.
For the
Thror (39 Ohm, 95.3 dB / 1mW), it would then require an amplifier delivering at least
0.5 Watt (500 mW) on 40 Ohm.
For the
Vali (45 Ohm, 100.4 dB / 1mW), it would then require an amplifier delivering at least
0.17 Watt (170 mW) on 40 Ohm.
For the
Magni (33 Ohm, 103.2 dB / 1mW), it would then be an amp delivering at least
0.07 Watt (70 mW) on 40 Ohm.
For the
Utopia (125 Ohm, 104.7 dB / 1mW), it would then require an amplifier delivering at least
0.17 Watt (170 mW) on 40 Ohm.
For the
HD-800 S (443 Ohm, 101.6 dB / 1mW), it would then require an amplifier delivering at least
1.3 Watt on 40 Ohm.
For the
LCD3-F (111 Ohm, 95.8 dB / 1mW), it would then require an amplifier delivering at least
1 Watt on 40 Ohm.
For the
HE-1000 V2 (35 Ohm, 86.9 dB / 1mW), it would then require an amplifier delivering at least
3 Watt on 40 Ohm.
For the
Abyss (45 Ohm, 83.5 dB / 1mW), it would then require an amplifier delivering at least
9 Watt on 40 Ohm.
For the
Susvara (62.5 Ohm, 80.6 dB / 1mW), it would then require an amplifier delivering at least
24 Watt on 40 Ohm.
For the
HE-6 SE (65 Ohm, 79.2 dB / 1mW), it would then require an amplifier delivering at least
35 Watt on 40 Ohm.
For the
HE-6 (44 Ohm, 74 dB / 1mW), it would then take an amp delivering at least
77 Watt! on 40 Ohm.
Source (in french):
https://musique-o-casque.com/viewtopic.php?p=3740#p3740
The
Auris Euterpe amp (
0.9 W RMS: 32-80 Ohm headphones) should be optimal to drive the Magni, the new Vali 2019 and the new Odin 2019, without breaking the bank.
The
Viva 2A3 amp (
3 W RMS on 50 Ohm?) should drive without difficulty, with the greatest distinction, with all the headphones above, including the Thror and Audeze LCD3-F, but a priori not the Abyss, neither the HE-6 nor the Susvara, to exploit to the fullest the potential of these headphones much more demanding in terms of amplification, in particular in capacity of current, than the other headphones mentioned.
The
Viva 845 amp (
15 W RMS on 50 Ohm?) would be perfect to drive the Abyss!