An improved power supply unit includes a DC power source having a positive terminal and a negative terminal, and a voltage regulating circuit that includes a plurality of elements coupled in series between the positive and negative terminals of the DC power source to regulate the power supply signals supplied thereto to effectively cancel ripple and noise in such power supply signals. In one embodiment, the series-coupled elements include at least one resistor and a transconductive element having a characteristic transconductance value of T. The at least one resistor provides a resistance substantially equal to 1/T. The transconductive element and the one resistor cooperate to suppress spurious voltage level variations produced by the DC power source. The transconductive element may be realized by a thermionic triode, field effect transistor or other suitable device. In an alternate embodiment, the series-coupled elements include at least one active device and a transconductive element which cooperate to suppress spurious voltage level variations produced by the DC power source.