I have a laptop, and when i plug it into my soundboard it makes a really loud
squeel, interference sort of sound. However, when i unplug my laptop, and
just use battery power, it works great. I was able to solve the output
problem by turning down the master volume, and turning up the individual
channel volume. So now i can listen to music without the squeel, but when i
want to record something, i plug the soundboard's line out into the
microphone jack, but it records the annoying squeel. Any ideas?