The Realtek ALC861 is an audio codec chip that was commonly used in motherboards and laptops during the mid-2000s. It offered basic audio processing and output capabilities, providing support for various audio formats and channels.

The ALC861 featured 18-bit digital-to-analog conversion (DAC) and 20-bit analog-to-digital conversion (ADC), delivering decent audio quality for the time. It supported 7.1 channel audio and included various audio enhancement features like 3D audio and multi-streaming.

While the Realtek ALC861 served well for everyday audio needs, it eventually became outdated as newer and more advanced audio codecs were introduced, offering higher audio quality and additional features.