# How does an equalizer prevent a sample and hold effect?

How does an equalizer prevent a sample and hold effect?

Does a reconstruction filter only smooth out the output of an DAC (+S&H) or does it have another function?

• Jim, i cannot agree with you. if the zero-order-hold effect of the DAC is known in advance (like, say, it's a "conventional" DAC, not a sigma-delta DAC), you can, if you're willing to put in a little delay, compensate in the frequency domain for the droop (which is -3.92 dB at Nyquist) of the ZOH. at least to some extent. but that compensation would be bad if the same samples went out to a DAC that operated at a high internal sampling frequency (like a $\Sigma\Delta$ DAC). – robert bristow-johnson Jan 8 '14 at 17:22