The present invention relates to a mixer apparatus (30) for mixing audio signals from a musical instrument (10). The mixer apparatus (30) comprises plural input circuits (34) and an audio signal mixer (36). Each of the plural input circuits (34) has an audio signal input which, in use, is coupled electrically with and thereby receives an audio signal from a different one of plural musical instrument pickups (32) comprised in the musical instrument. The audio signal mixer (36) receives audio signals from the plural input circuits (34) and mixes the received audio signals with one another. Each of the plural input circuits (34) comprises a linear active circuit in an audio signal path between the audio signal input and the audio signal mixer (36).