Exactly the same, the only one who is different is the Brut, the orifice doesn't have the belleville washers so it is not Balance Piston 1st stage.
So, all the FIRST STAGE - MAXIMUS SRB7600, OASIS SRB5700, BLIZZARD SRB5900, MAGNUM® SRB5300 are balance Piston 1st stage with Sealed Spring...