On page 14, #6 of the US Manual, it says only to use special Virtual Boy headphones. I was wondering why? To boost the sales of the headphones, or will regular headphones harm it in some way?

It almost looks like a note used to “cover themselves,” so that if someone did use different headphones and the headphones happened to cause damage somehow, they could say “hey, we told you right there to use these particular ones.” But yeah, I also can’t imagine how standard headphones that one might use for one’s Game Boy could ever cause harm to the Virtual Boy.

Benjamin Stevens wrote:
…I also can’t imagine how standard headphones…could ever cause harm to the Virtual Boy.

I think technically every headphones that have the same pin can use them in any device.
I have the original VB headphones but also use other brand name.

TRS connector

http://en.wikipedia.org/wiki/TRS_connector