[satasha]

I am wondering if a 600 OHM headphone amp would be too much or mess up the sound of 50 OHM headphones (Sennheiser HD 558).

 

[PurpleAngel]

Are you taking about the headphone amplifier built into the Sound Blaster Z or Zx?
(The 50-Ohm HD558 works fine plugged into the SB-Z or SB-Zx)
 
No such thing as a "600-Ohm" headphone amplifier (at least that I know of).
A headphone amplifier is rated by the manufacturer to be able to drive 600-Ohm headphones.

 

[mindbomb]

The 600 ohm thing means it is capable of a maximum voltage of like 5-7 volts rms at maximum gain at full volume. Usually, you have the option of using less gain to lower voltage for other headphones.

 

[satasha]

PurpleAngel, yes I am talking about the Sound Blaster Z.