  Signal digitizers revolutionized the approach to the electronics readout of
radiation detectors in Nuclear Physics. These highly specialized pieces of
equipment are designed to acquire the signals that are characteristic of the
detectors in nuclear physics experiments. The functions of the several modules
that were once needed for signal acquisition, can now be substituted by a
single digitizer. As suggested by the name, with such readout modules, signals
are first digitized (i.e. the signal waveform is sampled and converted to a
digital representation) and then either stored or analyzed on-the-fly. The
performances can be comparable or better than the traditional analog
counterparts, in terms of energy, time resolution, and acquisition rate.
  In this work, we investigate the use of general-purpose digital oscilloscopes
as signal digitizers for nuclear detectors. In order to have a proper
comparison, we employ a distributed data acquisition system (DAQ), that
standardizes the interface between the hardware and the on-line data analysis.
The signals, from a set of typical radiation detectors, are digitized and
analyzed with the very same algorithms in order to avoid biases due to
different software analysis. We compare two traditional signal digitizers (CAEN
DT5725 and CAEN DT5751) to two low-cost digital oscilloscopes (Digilent Analog
Discovery 2, and Red Pitaya STEMLab 125-14), in terms of their capabilities for
spectroscopy (energy resolution), time resolution, pulse shape discrimination,
and maximum acquisition rate.
