Volume Bypass determines whether the D/A Converters internal digital volume control is active.
When Volume Bypass is ON, the D/A Converter operates at its maximum output level without digital attenuation. Volume is then controlled in the analog domain by a dedicated preamplifier or integrated amplifier.
When Volume Bypass is OFF, the D/A Converters output level can be adjusted directly. In this mode, volume attenuation takes place in the digital domain.
Why Do We Recommend Volume Bypass to be ON?
At Vitus Audio, we recommend enabling Volume Bypass and using a dedicated analog preamplifier for volume control.
Digital volume control reduces the level of the music signal before it reaches the D/A Converters analog output stage. However, it does not reduce the noise floor generated by the analog circuitry after the digital volume control. As the volume is lowered, the music signal becomes progressively smaller while the analog noise floor remains unchanged.
Consequently, the signal-to-noise ratio and available dynamic range decrease as more digital attenuation is applied. This is particularly relevant at lower volume settings, where the music signal is attenuated most significantly in relation to the remaining noise floor.
With Volume Bypass enabled, the D/A Converter operates at its full output level and delivers the strongest possible signal to the preamplifier. Volume adjustment is then performed in the analog domain by the preamplifier, allowing the D/A Converter to retain its maximum available signal-to-noise ratio, dynamic range and low-level resolution.
Recommended Configuration
For the highest possible sonic performance, we recommend enabling Volume Bypass and controlling the listening level through a dedicated analog preamplifier. This allows the D/A Converter and preamplifier to perform their respective functions under the conditions for which they were designed.
