A Ternary Digital to Analog Converter with High Power Output and 170-dB   Dynamic Range
  A prototype of a very high dynamic range 32-bits Digital to Analog Converter (DAC) was designed and built for the purpose of direct auditory stimulus generation. It provides signals from less than 100 nV up to 50 Watts peak power output, driving a 32-Ohms earphone or speaker. The use of ternary cells makes possible a 170 dB dynamic range that is basically limited by thermal noise only. 
Guido Stolfi (University of Sao Paulo)
cs.AR