An apparatus for converting a continuous-time input signal into a sampled and quantized output signal, comprising: an input line for accepting the continuous-time input signal; a plurality of processing branches (110, 120, 130, 140) coupled to the input line, each of said processing branches (110, 120, 130, 140) including: (a) a continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), (b) a sampling/quantization circuit (114, 124, 134, 144) coupled to an output of the continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), and (c) a digital bandpass filter (115, 125, 135, 145) coupled to an output of the sampling/quantization circuit (114, 124, 134, 144), wherein each of a plurality of said digital bandpass filters (115, 125, 135, 145) includes at least one adjustable parameter which, when adjusted, changes a bandwidth and/or a center frequency of the frequency passband of said digital bandpass filter (115, 125, 135, 145); and a combining circuit, coupled to outputs of a plurality of said processing branches (110, 120, 130, 140), that combines signals on said outputs into the output signal, wherein the continuous-time input signal is a continuous-time, continuously variable input signal; and each of a plurality of the continuous-time quantization-noise-shaping circuits (113, 123, 133, 143) includes an adjustable circuit component which, when adjusted, changes a frequency of a quantization-noise frequency-response minimum of said continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), wherein said minimum is set to correspond to the frequency passband of the digital bandpass filter (115, 125, 135, 145) in the same processing branch (110, 120, 130, 140). an input line for accepting the continuous-time input signal; a plurality of processing branches (110, 120, 130, 140) coupled to the input line, each of said processing branches (110, 120, 130, 140) including: (a) a continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), (b) a sampling/quantization circuit (114, 124, 134, 144) coupled to an output of the continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), and (c) a digital bandpass filter (115, 125, 135, 145) coupled to an output of the sampling/quantization circuit (114, 124, 134, 144), wherein each of a plurality of said digital bandpass filters (115, 125, 135, 145) includes at least one adjustable parameter which, when adjusted, changes a bandwidth and/or a center frequency of the frequency passband of said digital bandpass filter (115, 125, 135, 145); and a combining circuit, coupled to outputs of a plurality of said processing branches (110, 120, 130, 140), that combines signals on said outputs into the output signal, wherein the continuous-time input signal is a continuous-time, continuously variable input signal; and each of a plurality of the continuous-time quantization-noise-shaping circuits (113, 123, 133, 143) includes an adjustable circuit component which, when adjusted, changes a frequency of a quantization-noise frequency-response minimum of said continuous-time quantization-noise-shaping circuit (113, 123, 133, 143), wherein said minimum is set to correspond to the frequency passband of the digital bandpass filter (115, 125, 135, 145) in the same processing branch (110, 120, 130, 140).