Introduced in 1991, the XK-S9000 has it all, from Dolby S Noise Reduction to a built-in D/A converter and remote control. The AIWA K-S9000 features a 4-motor dual capstan drive mechanism. When the cassette is loaded (this happens automatically when the cassette is dropped into the door) it is clamped agains a resilient pad to damp shell vibration, a system called by AIWA Super AMTS (anti-modulation tape stabiliser). The deck features 3-head design, with amorphous heads for both recording and playback with "stress-free 6N copper coils" for both the recording and playback heads. The heads are mounted in a ultra-stiff headbase casting that is mounted on three points to increase stability and a head stabilizer is used to reduce vibration of the head assembly itself.
The display has dual, 24-segment, peak level indicators while for calibration the deck has built-in 400-Hz and 10-kHz test tones for bias and level and an additional 3-point setting for Rec-EQ. Another unique feature is the BTOR system, Blank Tape Optimized Recording. There are two record buttons on the front, one marked "REC" and the other "B-REC". With B-REC the erase head is deactivated when using a virgin tape. Aiwa claims that the result is a well-dampened sound, sound expansion, less distortion and clear sound reproduction. The AIWA XK-S9000 has twin (external) power supply and built-in 18-bit linear dual D/A converters and 8xoversampling digital filter that allows direct optical or coaxial connection of a CD player. Needless to say, the XK-S9000 has Dolby B- and C-type noise reduction but it also sports Dolby S NR and defeatble HX Pro system. Frequency response is 13Hz - 21/22/23kHz (normal/chrome/metal) -20VU +/-3dB | Dimensions: 469(with side panels)*151*415 mm | Weight 14kg.