[LancerX]

N00b question warning:
 
In the past, I ran a single cable from my onboard Realtek sound output to a Plantronics headset/speaker switch, which allowed me to use speakers or headset as the circumstance demanded.
 
However, I recently took my first step towards higher-fi PC gaming audio, and upgraded to a Asus Xonar DG card and AT AD700 headphones (delivered today).
 
The AD700s have a published 32 ohm impedance, and the Asus card has a built-in headphone amp.  The amp feature supposedly has three settings :  0-32 ohms, 32-64 ohms, or >64 ohms.  Would the middle setting be appropriate for the AD700s?
 
If so, then I am guessing I should no longer use my headset/speaker switch - because the amplified signal would fry my computer speakers, right?  (My speakers are Altec Lansing's model VS2620.)
 
This Xonar card only has one 2-channel analog output, so I'm trying to determine how I might switch between speakers and headphones without crawling behind my desk, which is rather inconvenient...  Thanks in advance!

 

[obobskivich]

You do not want to feed a headphone amp output into the speakers, that is correct (nothing will "fry" though). The lowest or middle gain settings (0-32 or 32-64) are appropriate for your headphones. 
 
Regarding hooking up your speakers, that's a bit interesting indeed. From the Xonar manual, that front L/R output is what you should be using for both. What appears to make sense is leaving the switch-box, and just switching both the box (I'm assuming it's a mechanical switch that won't care about the signal) and the Asus' control panel between 2.1 speakers and stereo headphones when you want to make the switch. The manual mentions no other changes for hooking up a pair of stereo speakers.