Bjarney,
Your's sounds a bit like mine but mine is a big mamma - 100% duty cycle up thru 200 amps, rated over 400 amps on TIG.
These new 'inverter' welders are slick and portable but I don't think and of them will ever run DC as smooth as mine which has a 200 pound inductor in series in the output line. At moderate amps, the welding sounds more like a whoosh that the crackle you always hear about. At about 1000 pounds, it just isn't very portable.
