I have a 24 channel Soundcraft Spirit board. I'm having a problem with the main mix monitors. The speakers cut out and crackle unless the volume of the board is cranked past the halfway point. Even then it's sketchy. I took the amp and speakers to the shop, and there's nothing wrong with them. I already sprayed cleaner in the speaker outs of the board to no avail. I don't seem to have the same problem when I switch to 2 track playback on the board. But I don't know if this is because I usually use it for cds, which tend to have a much more consistantly louder volume than whatever it is I'm working on (being as they are mastered and such) which keeps the volume up past the threshold of where the cut out begins. I've been told it might be the op amp? The cut out happens on both speakers intermittantly. Any ideas? Is it something I might be able to fix myself?