Measurable and audible effects of aftermarketop-amp replacements in audio interface microphone preamplifiers

Sammanfattning

This paper investigates the practical merit of modifying commercially availabl eaudio equipment by means of drop-in op-amp replacements. A common model of audio interface with a typical microphone input topology was selected as a modification candidate,representative of the type of device that may be considered for such a modification. Its preamplifier section was reverse-engineered, and two pairs of channels were modified, one with high-end, modern op-amps, and one with low-cost legacy op-amps, while one pair wasleft in its exact factory configuration. Measurements show observable, though practically in-significant differences between all three configurations. Confirmatory listening tests indicateno significant audible variation between configurations.