Sulfur isotope fractionation plays a crucial role in understanding the evolution of sulfur concentration and isotopes in natural magmatic systems. This is because sulfur has multiple oxidation states varying from -2 to +6, a multitude of reactions, not limited to precipitation, dissolution, phase separation occurs in these systems. It is during these reactions, in a dynamic environment, that sulfur could fractionate. Understanding this fractionation can help us estimate critical parameters related to degassing processes, such as magma ascent rate, residence time in the reservoir. We conducted experiments in dynamic conditions to determine sulfur isotope fractionation factors in a magma containing sulfides, in a 1-atm gas-mixing furnace using the gas mixture CO-CO2-SO2. Disequilibrium conditions in the furnace can be modelled to simulate volcanic degassing, as the maximum rate of the change of fO2 within the furnace is 0.013 log unit s-1. Sets of time-series experiments have shown that the system reaches equilibrium, both in terms of major element and sulfur isotope composition within 8 hours. Once at equilibrium, dynamic conditions were imposed, by varying fO2 & fS2 from the initial to the final conditions. From initial tests at 1300 °C, changing ~1.2 log unit over 4 hours (log fO2= -10.3 to -11.1, log fS2= -1.2 to -2.5). At the start the Δ34Smelt-sulfide is 0.8 ± 0.8 ‰ and after 4h we measured a Δ34Smelt-sulfide of -0.1 ± 0.5 ‰ which is in agreement with the expected equilibrium value of -0.4 ± 0.3 ‰, but the kinetic effect of isotopic fractionation remains hidden by the poor analytical precision. We will further test and present the results from multiple series of dynamic experiments at 1300 °C, running from a reducing (log fO2, fS2: -11.1, -2.5) to an oxidizing condition (log fO2, fS2: -8.5, -1.4) each lasting a duration between 5 minutes and 1 hour after equilibration. The equilibrium isotopic fractionation values for these 2 conditions are Δ34Smelt-sulfide of - 0.1 ± 0.5 ‰ & 8.2 ± 0.6 ‰. We expect to see a more significant and measurable change in Δ34Smelt-sulfide, showing how sulfur fractionates during rapid natural degassing processes and the kinetic processes at play.