The purpose of the present study is to determine for the balanced-pair tunnel-diode circuit the minimum amount of control required when specified parameter imbalances are present in the system. The problem is formulated and the minimum control is determined numerically. These results are compared with an analytic formula for the minimum control which is presented here but is derived in another paper. The results obtained may be used to determine allowable tolerances on the circuit components for a given requirement on the maximum amplification or the total number of input and output connections. COPYRIGHT © 1963—THE INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS, INC.