A digital mixer has a panel and a mixing processor configurable in matching with a scene to mix audio signals fed from input channels and to feed the mixed audio signals to output channels. The panel has an operator manipulable to operate the mixing processor, and a display provided for displaying a state of the mixing processor. Further, a storage is provided for storing configuration patterns of the mixing processor in correspondence to various scenes. A retriever is provided for calling one of the various scenes and for retrieving the configuration pattern corresponding to the called scene from the storage; a selector provided for selecting one of a preview mode and a non-preview mode. A controller operates when the non-preview mode is selected for actually configuring the mixing processor according to the retrieved configuration pattern to thereby enable the mixing processor to reproduce the corresponding scene, and operates when the preview mode is selected for producing a preview of a configured state of the mixing processor according to the retrieved configuration pattern without actually configuring the mixing processor to thereby enable the display to present the preview.