Electronics grade isopropanol. Guy's I am certified to NASA workmanship standards. I do this for a living. No flux flies in space for a reason. -- View this message in context: http://elecraft.365791.n2.nabble.com/k2-Poor-USB-audio-after-cal-tp6616641p6620834.html Sent from the Elecraft mailing list archive at Nabble.com.