The evolution of One Audio Processor

摘要

The advent of the "Talkies" was immediately followed by the 1929 Stock market Crash, and as a result few Cinemas could find the £4000 or so needed to equip their typically noisy and reverberant "Hall" auditoria.rnFor those who could afford to add sound, amplifier design was clearly in its infancy. The existing "Public Address" (PA) Amplifiers of the 1930s used low power triodes in basic transformer coupled circuits without any negative feedback. 10 to 20 Watts output was all most Cinemas could afford, and high loudspeaker efficiencies were needed to fill those large spaces. This need for high sound levels from so little power led to a number of impressive split frequency horn-loaded loudspeaker designs, and some of these designs were not only used well into later cinema sound eras, but their influence spread deep into the live music market during the 1960s and onwards up to today.