AMPLIFIERS. ----------- The amplifiers who are used to amplify the signals to the modulator tube,are special. They must amplify from DC to 10MHz linearly.The amplifiers are typical voltage amplifiers who amplify the signal 1000 times. Another thing about them are that the outputsignal can change polarity completely. At 0 Volt input the output shall be -3000 Volt. At 3 Volt input,the output shall be 0 Volt. At 6 Volt input the output shall be +3000 Volt. The first stage of the amplifier consist of integrated circuits. The mediate stage consist of discrete transistors. The output stage consist of 2 electron tubes of the type PL518. Most of the amplifier are powered with +/- voltage with middle tapping. The power of the amplifier are approximate 100 watt pr channel.