circuit inside of CD/DVD drive which connects to the photodiodes. A switched capacitor circuit used to null the effects of mismatch offset in most CMOS comparator-based flash analog-to-digital converters Due to its unique coloration, some preamplifiers can be emulated in software to be used in mixing. See also Low-noise amplifier (LNA) Instrumentation amplifier Buffer amplifier Logarithmic resistor ladder External links Electronic amplifiers Audio engineering