connecting non-powered speakers to a SB128 without an external amplifier?

[wiebe]

Recently I bought a SB128-card. To improve the soundquality the best thing to do is connecting the soundcard to an external amplifier and two non-powered hifi-speakers, instead of the standard solution (two powered speakers). In the SB128-manual they claim that the green line-out can be used for "... an external amplifier or non-powered speakers ...". Mind the word "or". It looks like one can connect non-powered speakers directly to the SB128 without using an external amplifier. Obviously all you have to do is switch jumper JP1 from the standard "front line-out" to "speaker-out", connect the hifi-speakers with the green line-out and that's all. But I don't want take any risk blowing up my two expensive 100W-loundspeakers by trying this possibility, so the question is:
is there someone how has connected two non-powered speakers directly to a SB128, thus without the use of an external amplifier? Please let me know your results!!