8 servos are too much

4 standard and 4 mini servos I connected all 8 new servos to the servo controller (which already served the 2 cam and the rudder servos), and saw some electric Parkinson happening. As soon as I tried to control one servo all others started to adjust their positions erratically. Hm, why was that?

I started disconnecting the servos and found that a total of four worked OK. After some research I found a standard servo pulls up to 0.6A. Oops! I seriously doubt AAs deliver 11 x 0.6A = 6.6A without some dent in the output voltage...

It seems that when too high a current is drawn the voltage drops significantly. The servos interpret this as a change in position (after all, position gets measured as a voltage drop over a variable resistor), and an adjustment orgy ensues, with more servos moving and more current being drawn, until complete breakdown of civilized behavior.

Either some D batteries are due, or I better use the 8 new servos in a stationary project with a PC power source (a 300W supply with +5V/12A should suffice).