I have bought amplifier 33 years ago, and paid 750 Deutsch mark about 300$. Pioneer for first time used self-developed high speed, ultralinear transistors(rets)ring emitter power. Amplifier can make the best of an ultra-wide power bandwidth, perfectly to their dynamic capabilities, in terms of both , power and timing. Their(DC) direct current, without coupling capacitors ensures proper infrasonic response, without any phase shifts. Also the non-switching format of the power transistors eliminates high frequency switching distortion. Built in the low-noise, high grade components significantly lower the bottom limit of dynamic range, so that the softest musical passage can stand out against a background of almost perfect silence. Sound is one of cleanest and harmonious when listening an orchestral crescendo, and unbeatable in pop-rock musics with transparent, fresh-sounding tonality, compared to many other amplifiers on the market that time and also in my opinion today. Pioneers magic word "everything you hear is true" I considered was absolutely t r u e . I will listen my SA 710 DC till I die.