Ultra three of a tube to the Class A single ended amplifier

When the audio input signal to 1 V, the output power of 6 W; increased to 1.6 V input, the output power of up to 15 W, input and output into the slope of the curve of the uniform, linear good. 

Ultra-transistor to the law in the 12 W power output, from 100 HZ ~ 10KHz within the scope of distortion of about 2 percent. 

KT88 ultra-transistor to the power of the frequency response of cents, from 20 Hz ~ 20KHz gain in less than 1 dB; as a general standard to law, their frequency response of 20 HZ ~ 10KHz from the gain in more than 2 dB.