Originally Posted by kkcc
You would anyway need a desktop rig to get close to driving those 300 or 600ohm cans properly. Even an entry level Magni at $99 will give you 130mW at 600ohm. What would Fiio achieve even if they double (to 60mW), or even triple (90) the X3 power? You still cannot drive these cans properly. Trying to power high impedance cans with portables is inherently a fool's errand.
Sorry, but I would not call it "inherently a fool's errand". "Properly" is relative -- your proper 120db peak sound level may be too loud or even painful for someone else's music/preference. Especially when you are listening to quiet classical music loudly, while the other guy is listening to hot-mastered Rock at low levels.
It is nice to get peak level to over 120db. However, Many people don't go over 85 db in average listening volume and many ordinary recordings do not have more than 25db difference between average volume and peak volume (some difference is lower than 12db). So to get 115db peak from an ordinary recording, one may have to turn up your average listening volume to over 90db, which may be too loud for some ears. Long term listening at 90db may not be healthy for your ears either.
There is no doubt that a stationary amp may perform better than portables. However, just from sound level perspective, even Fiio X3's output power can achieve 111db from HD600s (or 114db from HD650). Many non-classical listeners may be reasonably happy with 115db; those who listen quietly may be fine with even 110db. When a listener choose to listen portablely, he/she may not mind slightly trade-off.
Hifiman or Audeze orthos are a different story, which are better off with stationary amps. Still, many Headfiers run those portably. I doubt any portable rigs can drive LCD-2s to over 120db.Edited by zzffnn - 9/26/13 at 10:18am