Unlike the standard graded (circuit breaker) and adjustable machines, Synergic MIG gas metal arc welding machines with Tristor provides sensitive voltage adjustment for unlimited range by means of a potentiometer. After welding wire diameter (0.8-0.1-1.2-1.6 mm.) and protective gas (CO2, Mix, Ar) is selected from the menu, the machine adjusts the wire speed automatically. The welder obtains the ideal welding result in his/her desired position without bounding by making the adjustments with only one button. Since the potentiometer is on the wire driving unit in varyo models, the welder receives the ideal welding settings perfectly by controlling remotely. It has 2 and 4 grade trigger options. They are automatic air or water cooled welding machines with thermic protection circuit, soft-arc feature that minimizes the bounding during the beginning of welding, burn-back feature that inhibits the wire to be attached to the part, and method welding feature in which the time can be set.