I bought a near mint condition vintage sansui AU-555A in pier, about 4 or 5 yrs ago. haggled it for 2.3K without the step down voltage transformer. it has separate bass, midrange (YES! midrange) and treble controls. I see indications it was manufactured in Japan in 1971. I haven't replaced any capacitors or any parts inside, its build is very good.
Lately I paired it with a used acoustic research M4 holographic imaging speaker I got from a garage sale, ...and the music is.... very sweet, very musical.... I love the midrange....and the bass.... no need for subwoofer for well recorded CDs...
It has been compared to having a sound very close to that of a tube amp. see below:
Here's a bit of the good description from
http://www.sansui.us/Amplifiers.htm"Once upon a time, Sansui was a mere transformer manufacturer. It was natural progress that Sansui started manufacturing amplifiers and tuners in its early history. In the late 1950Â’s to the early 1960Â’s, Sansui had developed a sense of mission to be a world class audiophile manufacture. That was the reason that Sansui introduced the first pre-main (integrated) tube amplifier SM-88 in Japan. Sansui introduced only two more tube integrated amplifiers, AU-70 and AU-111, before they moved forward to the solid state silicon transistor amplifier, AU-777 in 1967.
From 1967 to 1970, Sansui introduced the array of the single number three digits integrated amplifiers. They were AU-222, AU-333, AU-555, AU-666, AU-777, AU-888, and AU-999 followed by improved versions;
AU-555A and AU-777D. The sound of this series was very close to that of tube amps. Even mixing with tube amplifiers with frequency divided multi-power amps system, it sounded natural".
