Power supplies for laboratory use are mostly only power sources.
They are only able to deliver power with one single polarity, i.e. these instruments only work in one quadrant of the output voltage/ current diagram.
Common amplifiers deliver voltages with both priorities, but are generally unable to absorb power values in a range comparable to that which they are able to deliver. They therefore mainly work as two-quadrant devices.
The TOE 7610 series of four-quadrant amplifiers is able to work as a power sink as well as a power source with equal values of delivered or absorbed power.
The TOE 7610 series is thus a voltage amplifier, bipolar voltage and current source, and current sink in one instrument.
Having to combine different instruments, where problems frequently occur with the coordination of individual components and the tendency to oscillate, now belongs to the past.