Glynn is dead right, the MFA controller is a resistive one, the BoBs board uses seperate resistors to achieve the same. Looking around, the MFA and hobbies “mechanical speed controller” (which may be the same animal) are about £16, but an Mtronics 15A Viper ESC is about £22, so really not much difference there, however the mechanical ones cant compete in the fine control and efficiency stakes. There cant be much reason surely for using a Bobs or resistive unit anymore??? (unless you make your own) Ashley