[dukeReinhardt]

guys i'm not familiar with headphone power requirements and such but i'm going to be getting something like an essence stx soon (specifically looking at the creative zxr, which uses the same chip and presumably similar circuitry). i hear it actually has not a lot of power output (mW).


here's a quote regarding the headphone amp section:
 
"TPA6120A2 is able to swing only within +|-10 V with +|-12 V supply and 10 kOhm loading.
Measured output power with 33 Ohm loading is 650 mW.
Measured output power with 300 Ohm loading is 120 mW."
 
and here's another source that says it outputs ~200mW at 62ohms:
 
http://www.head-fi.org/t/476602/asus-xonar-stx-built-in-amp-and-k701-synergy
 
my headphones, the HD 280 pro, are supposed to have a max input wattage of 500mw and they're 64ohm. some headphone amps can output up to 1w, and the stx doesn't seem able to do that. does that make it a poor investment as an amp (i do intend to branch out from the not-so-great hd 280 at some point), or does it mean it might not be enough for the hd 280? basically what do these numbers mean, and could you give me an example (like a specific headphone) where the stx would be inferior to a 1w headphone amp?
 
regarding resistance, am i right in understanding that the resistance in ohms is only significant because the resistance of your headphones should be 8 times or more than the output resistance of the source?
 
thanks

 

[dukeReinhardt]

sorry i keep double posting when trying to edit....

 

[cssarrow]

33 Ohm loading is 650 mW is actually very good.
 
Having lots of wattage doesn't mean it will sound good.
 
I have the Essence One which is 650mW at 35 ohm yet it sounds incredibly good with a HE-500 when people say they need around 1W to really shine. 650mW will be enough. It runs all my Sennheisers just fine.
 
If you still are too worried about driving power, you can grab a Schiit Modi/Magni for $200. It has 1.2W, however doesn't sound as good as my E1 even though it has twice as much power.
 
Tim

 

[PurpleAngel]

My Essence STX can drive my 600-Ohm headphones.

 

[dukeReinhardt]

thanks for the replies. anyway i've read a bit more and it seems the card i want will probably have different power output anyway