A pedal board assembly for receiving a plurality of musical sound effect generators generally comprises a box-like receptacle with a removable lid. The receptacle contains a top tier of flat, fixed pitch panels including a power supply and an audio circuit interface. A middle tier is of a fixed, tilted pitch and a lower tier is of selectively flat or tilted pitch mode, the tilted pitch mode matching the pitch of the middle tier so that large sound effect generators may be placed across to span both the middle tier and the lower tier.