A highly distributed current reference for a solid-state memory comprises a centrally located current digital-to-analog converter and a plurality of remotely located tile current references. In one embodiment, the invention includes receiving sets of telephone audio signals from conference subnodes, the telephone audio signals corresponding to subscribers of the conference call, selecting an output set of telephone audio signals from all of the received telephone audio signals, and transmitting the output set to the conference subnodes. The bottom member engages with the housing proper and the scroll guide member.