[jakeddong]

Hi, newbie here. I found that some headphones need an amp to get most of out it cause they have high impedance. Just wondering from what impedance and on would you need an amp? 
 
Also is a Fiio E7 enough to drive a pair of headphones at 300 ohms?
 
Would it be a waste of money to spend $100 for an amp to use it on a pair of headphones at 32 ohms that cost around $250?

 

[keanex]

The FiiO E7 can not properly drive a 300ohm pair of headphones. 

 

[TheWuss]

impedence isn't the only part of the equation.
it's also the sensitivity of the headphone.
this is usually measured in decibels per milliwat.  (dB/mW)

 

[ZARIM]

The AMPs usualy Amplify the signals into clean and better sound like it's gives power to music with more soundstage, better separation, imaging and overall improve the details(best to use with lineout in portable setup like ipod dock, S:Flo2, Sony X1060). The more powerful the AMPs is the better it's drive the high impedance headphones like iBasso PB2 can drive easily 300 Ohm headphones with high volume. But most portable budget AMPs are good to drive 32 Ohm to 150 Ohm and they improve overall sound quality like E11, T3d, Tomahawk.

 

[fabio-fi]

Quote:

Would it be a waste of money to spend $100 for an amp to use it on a pair of headphones at 32 ohms that cost around $250?

Not necessary a waste. Most of the headphones benefit from amping. There are certain 32 ohm headphones which sound better when amped. 

 

[Uncle Erik]

Impedance is only 25% of the equation. You also need to consider the amp's output power, the amp's output impedance and the headphone's sensitivity.

Headphone impedance, by itself, tells you very little.

 

[barleyguy]

Quote:

Impedance is only 25% of the equation. You also need to consider the amp's output power, the amp's output impedance and the headphone's sensitivity.

Headphone impedance, by itself, tells you very little.

Agreed.  Also, don't forget output voltage, or maximum voltage swing.  The signal to high impedence headphones will clip if the amp doesn't have enough voltage, which is mainly a consideration when running high impedence phones with portable amps.
 
 

 

[Joris]

Wouldn't one of the main advantages of a headphone amp be the high and stable input impedance?
 
The input impedance of a headphone amp is generally a lot higher than that of the most exotic headphones. The input impedance will be more stable over the frequency band than the coils in a headphone.
 
Because of this the headphone amp draws less current (thus power) from the source and the source will provide a cleaner signal as a result.
 
The headphone amp is dedicated to driving headphones and will have less problems providing a stable and sufficiently powerfull signal to drive the headphones.

 

[Tacoboy]

Quote:

Hi, newbie here. I found that some headphones need an amp to get most of out it cause they have high impedance. Just wondering from what impedance and on would you need an amp? 
 
Also is a Fiio E7 enough to drive a pair of headphones at 300 ohms?
 
Would it be a waste of money to spend $100 for an amp to use it on a pair of headphones at 32 ohms that cost around $250?

On eBay they sell single tube headphone amplifiers that will work with 300-Ohm headphones.
They ship the amplifiers from China, they can be as cheap as $50.
 

 

[barleyguy]

Quote:

Wouldn't one of the main advantages of a headphone amp be the high and stable input impedance?
 
The input impedance of a headphone amp is generally a lot higher than that of the most exotic headphones. The input impedance will be more stable over the frequency band than the coils in a headphone.
 
Because of this the headphone amp draws less current (thus power) from the source and the source will provide a cleaner signal as a result.
 
The headphone amp is dedicated to driving headphones and will have less problems providing a stable and sufficiently powerfull signal to drive the headphones.

 
Agreed.  This is one of the benefits of a headphone amp.  There are many sources that perform much better into a line level high impedence input than they do into headphones.