Stereophonic telephones "TDS-3".

Headphones, headphones, headsets ...Stereophonic telephones "TDS-3" from the beginning of 1977 were produced by the Ryazan Radio Plant. The telephones are designed for individual listening to stereophonic programs from various household mono and stereophonic radio equipment. The nominal power of the audio signal supplied to the phones is 1 mW, the maximum is 0.5 W. The range of effectively reproduced sound frequencies is 20 ... 20,000 Hz. The mass of telephones is 500 gr. The cost is 20 rubles.