Castle bec's are adjusted using the Castle Link, no other way to adjust them that I know of. Your servo may say 4.8v or 6v, but in reality bofh are nominal voltages. A 4 cell receiver pack is 4.8v nominal but is over 4.8v when fully charged. A 5 cell receiver pack is 6v nominal but over 6 volts fully charged. Servo manufacturers use these nominal voltages for their torque ratings because they are common voltages used in rc.
Not sure where you heard Spektrum is Savox but Spektrum was developed by JR. The first Spektrum radios just JR transmitters in grey and converted to 2.4ghz. They even came with JR servos that were grey instead of black. I bring this up because I setup the BEC in my nephews LST for 6.2v and the old JR590's have been fine for years. Believe it or not the extra .2v made a difference, at 6.0v the led's on his truck would dim ever so slightly when turning. Set to 6.2v and no dimming at all.
Last edited by Maj_Overdrive; 12-17-2014 at 07:54 PM.
Reason: Starting over