  We describe a simple procedure for reducing ADC common noise in modular
detectors that does not require additional hardware. A method using detector
noise groups should work well for modular particle detectors such as segmented
electromagnetic calorimeters, plastic scintillator hodoscopes, cathode strip
wire chambers, segmented active targets, and the like. We demonstrate a
``second pedestal noise correction'' method by comparing representative ADC
pedestal spectra for various elements of the PIBETA detector before and after
the applied correction.
