does a Vbe multiplier effects the sound quality for IRFP240 9240?

It has little to do with any sonic quality but rather better matching of thermal properties. Which device would be better suited to track the thermal properties of a mosfet, a BJT (which has vastly different Gm characteristics) or a mosfet that is somewhat similar in construction and material? Since you are using mosfet outputs, it would be considered a Vgs multiplier, no? I suspect the BJT may overcompensate and you will have to add emitter degeneration to get it to track more closely.