Extractor for Hi-res Lossless Audio

A Audio Extractor supports stereo PCM with up to 24-bit resolution and up to 192 kHz sample rate at its optical Toslink output. For a source device to output higher sample rates than 48 kHz, a corresponding EDID mode for 2-channel PCM with a high sample rate must be selected or negotiated on the Audio Extractor. Many televisions report only PCM up to 24 bit/48 kHz via their EDID. Therefore, when the TV’s EDID is used, the audio output is often limited to 48 kHz. In this case, a virtual EDID must be selected on the Audio Extractor. This is possible with the FeinTech AX210, AX341, SW212 and SW411.

For stable operation, the connected DAC must explicitly support 96 kHz or 192 kHz at its optical input and must have a sufficiently tolerant S/PDIF receiver with robust clock recovery or PLL performance. Some uncompromising high-end DACs that are optimised for extremely low jitter may react more sensitively to minor clock deviations or limited signal margins in the optical transmission path. This may cause the DAC to lose signal lock briefly, resulting in audio dropouts. In such cases, limiting the sample rate to 96 kHz or 48 kHz is recommended.

It should also be noted that comparatively little stereo content is actually available at 96 kHz or 192 kHz. Enabling support for up to 192 kHz in the EDID therefore does not automatically mean that every audio signal will be output at this sample rate.

When using a computer as the source:

On a Windows PC, the audio signal is converted to the standard format selected in the sound settings when operating in normal Shared Mode. For example, if 24 bit/192 kHz is selected, content with a sample rate of 44.1 kHz or 48 kHz will also be resampled to 192 kHz. This does not add any audio detail. At the same time, it increases the demands placed on the Toslink transmission path and the DAC, which may increase the risk of audio dropouts.

For the best possible and largely unaltered audio output under Windows, suitable playback software and exclusive output via ASIO or WASAPI Exclusive Mode are required. This allows the sample rate to be changed according to the source material and avoids unnecessary conversion by the Windows audio mixer. For normal Windows operation, 24 bit/48 kHz or 24 bit/96 kHz is therefore usually the more practical and stable setting.

On macOS, the sample rate and bit depth of the selected audio output device are set in the “Audio MIDI Setup” system application. Setting the output to 192 kHz permanently typically causes Core Audio to upsample content with a lower sample rate without improving the quality of the source material. For playback that remains as close as possible to the original source, suitable audio software with exclusive Core Audio access and automatic sample-rate switching is required.