Quote:
well i try with VAC and works fine but works for a minute ok and after the sound goes bad for a few seconds and again come back, and repeats.
any help for this ?
That can happen if the sample rate of VAC differs from that of the sound card. Say VAC runs at 44.099 kHz and the sound card at 44.101 kHz, then you loose 2 samples per second (for bigger differences you loose more, of course).
Check the buffer filling in Stereo Tool, if it gets too full (blackbar appears) or too empty (blue runs out), configure VAC to run slightly slower or faster.