Precise timing calibration of the chip is needed, followed by interpolation of the sampled data to get a uniform sampling rate. In addition, windowing effects are introduced when the Fast Fourier Transform (FFT) is calculated for short data vectors. For one DRS4 readout, the number of useful bins is less than 1024. Nevertheless, a lower bound for the ENOB can be stated. Following the description in [9] and accepting the extra distortion, the ENOB has been measured to be in the range 8–8.5 bits both for DRS4 readout and transparent mode sampling. Note that these results were obtained without gain calibration of the DRS4 cells [4] or using a low-jitter clock source. More sophisticated calibration and less timing jitter are expected to improve the results.