The performance of any current stabilizer can be predicted in terms of two parameters defined as the stabilization transconductance, gs, and the output conductance, go. Together with the equivalent circuits of Figs. 2 and 3 these two factors permit the calculation of the stabilizer performance in conjunction with any load circuit and direct-current supply. Fundamental stabilizer circuits based on the degenerative and mu-bridge principles are developed and analyzed for the two parameters defined. For simple circuits, the analysis suggests the use of pentodes to obtain best stabilization. Superior performance can be obtained by the mubalance circuit described. This circuit provides an output current substantially independent of any input-voltage or load-circuit change.