I am going to have to try an duplicate this problem. So far this seems to be a problem that is experienced with the 56** series servos, I have seen no mention with the 59** series. I am aware that all the HiTec digitals are using the same digital amplifier's, I think it would be safe to rule out a difference with the amps. The 56** are 3-pole motors and the 59** are coreless motors.

As I mentioned I have several Giant Scale models with wyes and HiTec 5945 digitals on 6volt Duralites. One model has [3] 5945's with one custom wye per stab half and the same basic setup with [3] on each wing section. Never had any problems with the wyes. I am using unbuffered plain old custom wire length tailor made wyes. One per stab or wing that allows me to connect all the servos to itself and then provide enough wire length to make it to the fuselage connection point. These are made to fit the model possibly the lack of multiple connectors and extensions is creating less resistance. I noted that someone mentioned the addition of a boosted/amplified wye solved his problem.