A method includes accepting an analog input signal including a sequence of pulses of a given pulse shape. The analog input signal is distributed to multiple processing channels (40) operating in parallel. The analog input signal is sampled by performing, in each of the multiple processing channels, the operations of: mixing the analog input signal with a different, respective modulating waveform to produce a mixed signal; filtering the mixed signal; and digitizing the filtered mixed signal to produce a respective digital channel output.