New to the site and new aspiring weldor. Taking tig classes at the local c.c.. Just purchased my new Dynasty 200 DX and love it, however, is it typical for this machine to make noise at idle or when machine is on but not in use? It sounds similar to a refrigerator running, or overhead power lines, or maybe a ballaster from a flourescent shop light. The machine works great but just want to be sure that it does make noise when on and not in use. -- Don't want to be stuck with a $3000 defect.