A reconfigurable digital bridge for calibrations of four terminal-pair defined impedance standards in the whole complex impedance plane by means of fully digital (FD) operation of the bridge and for R-R and C-C calibrations by means of involvement of reference inductive voltage divider (IVD) in digitally assisted (DA) configuration have been built during last years. For the bridge purposes, a high accuracy digital voltage sources operating in audio frequency range with full isolation between modules and with battery operation mode were developed. Together with coaxial switches with negligible crosstalk between channels, voltage sources form a base for full automation of the calibration process. The bridge was tested in both FD and DA configurations. Depending on the configuration, different relative accuracy of measurements can be achieved in the range from few parts in 10⁸ to few parts in 10⁵.