Sony STR-GX80ES Technical Background - Page 30

Sony's Optimum Preamplification (OP) circuit improves the signal-tonoise ratio across a broad range of volume control settings. The latest version of the OP design controls volume with twice the resolution of our previous design-0.5 dB steps instead of 1 dB In Sony's previous OP design, the volume control operated in precise 1 dB steps. However Sony found during critical listening at high volume levels that smaller steps are sometimes useful. That's why the STR-DA3100ES and DA2100ES incorporate a refined OP Processing system that enables you to vary the volume setting in precise, 0.5 dB steps! Optimum Preamplification is made possible by Sony's proprietary CXD9725 integrated circuit. Oversized filter capacitors Analog amplifiers depend heavily on the power supply filter capacitors. Because these devices filter out 60 Hz line frequency hum, they play a crucial role in protecting sound quality. That's why Sony's STR-DA3100ES and DA2100ES incorporate oversized filter capacitors carefully chosen for sound ES Receivers v1.0 Page 30