An audio mixer for the Amiga. It 'crossfades' the left and right audio to make listening with headphones easier and can also mix in CD audio. Full schematics, PCB and BOM provided.
Construction details and MP3 audio samples of the corssfade effect are here, http://www.ianstedman.co.uk/Amiga/designs/Audio_Mixer_MK2/audio_mixer_mk2.html