Originally Posted by randomZash
TF10 is 32ohms, not something I would call high impedance. Though it may help, any modern smartphone shouldn't need an amp.
to answer your question....sorry I don't know the exact number but you shouldn't worry
Obviously you're not familiar with the output impedance of an amplifier.
The TF10 have a wild impedance distribution thus i you don't plug them to a source with less than 2 ohms of output impedance you'll get a hole in the frequency response (In the treble in the case of TF10s).
An as of now the only smartphones with less than 2 Ohms of output impedance are the iPhones. That's the objective truth that i wish the S3 can change.
For the record:
there are two reasons to need an amp when driving headphones:
The TF10's as most multidriver armatures are likely to need an amp in order to get a linear signal.
Edited by elfary - 5/22/12 at 12:26am