A novel modular probe may include an interchangeable (connectable/disconnectable) probe-tip adaptor having a tip connector for coupling to a device under test, and further having a probe-tip terminal for coupling to a first assembly connector of a cable assembly, which further has a second assembly connector for coupling to a first build-out terminal of a build-out adaptor, which also has a second build-out terminal for coupling to an assembly connector of an interchangeable instrument connector cable assembly, which also has an instrument-end connector for coupling to a measurement instrument. The built-out adaptor may include a compensation adjustment circuit for compensating the probe for varying system capacitances. The probe may include one or more corrective circuits in the interchangeable probe-tip adaptor and/or in the build-out adaptor for at least partially terminating each end of the cable assembly with a characteristic impedance of the cable in the cable assembly to attenuate reflections.