thanks. will try to replace opamps it seems easy enough. will do so systematically to try to find out what is what. i will post when this is done if successful or otherwise. again thanks.

so the dac must work it ouputs to stereo speakers?

yeh three and they are cheap

i have recently installed an asus xonar stx card. initially everything worked fine but i find the right hand channel on the headphone amp doesnt now work. all else does and has been checked. would new op amps resolve this or at least possibly!