Abstract: The disclosure relates to a molten metal producing and refining method which does not damage the apparatus, realizes a stable and high second combustion rate, and is capable of effectively recovering heat generated by the second combustion. The method comprises introducing a metal-containing material, a carbonaceous material, a flux and O.sub.2 gas into a furnace. The carbon which dissolves into the metal bath in the furnace from the carbonaceous material is combusted with the O.sub.2 gas to generate heat and CO gas. The CO gas is subjected to the second combustion with the O.sub.2 gas to additionally generate heat, and the metal-containing material is melted and refined by both the generated heat and carbon. The method is characterized in that O.sub.2 gas or O.sub.2 -containing gas is blown into the furnace through large-diameter tuyeres installed near the bottom of the furnace and a part of the O.sub.

Abstract: A balance control system for multichannel audio apparatus wherein stereophonic signals are transmitted through plural audio channels of the audio apparatus. The balance control system includes a balance control network connected to the audio channels for selectively adjusting the relative amplitudes of the respective stereophonic signals transmitted therethrough with respect to each other. The balance control system further includes at least one signal delay circuit included in at least one of the audio channels for establishing relative delays among the transmitted stereophonic signals. The delay circuit is controlled simultaneously with the control of the balance control network.