I've got an amp in that had the original 4 erf7530 mosfet and we changed them out for the 4 erf9530 supposed drop in replacements. Before the swap the amp would output around 175 watts peak but would only dead key around 4 to 8 watts with a swing of 175. With the new erf9530 the dead key is about the same but now only swings around 70 to 100 watts. I changed a few caps out that were reading weird on my meter and 2 of the erf7530s were bad I checked everything else I could and still I hear myself through something in the amp and have a low dead key with not much swing. Would anyone know why this amp seems like it's output is low or why it's acting like something is holding it back. I'm running good voltage of 12.8v or better into the amp with a dead key of 3 watts swinging 20.