It came out in 1983 together with the DX7 representing a less expensive alternative, for those seeking a full synthesizer below the 1.000$ point.
Using the same shell of the bigger brother, it simply cuts lots of the functionalities of the 6op DX7 just for a cheaper price back then. Unlike later 4op synths, there are no features to compensate the reduction of capabilites.
Moreover, as the keyboard is not velocity sensitive, todays is considered one of the worst entries in the FM family. That also means that it can be easily found below 100€, although prices are quickly rising.
120 preset sounds on voice cassette provided. 20 available from the moment you switch on.
Full programmability with 4 operators and 8 algorithms providing endless possibilities.
Simple storage of your programmed sounds on standard cassette tape using a personal stereo or datarecorder – Swap voices with other DX9 owners.
MIDI equipped for other MIDI instruments and devices.
Extra expression using optional remote keyboard (KX5) or breath controller (BC01).
FM tone generator (4 operators, 8 algorithms)
Simultaneous note output
Polyphonic: 16 notes
Monophonic: 1 note
Voice memory: 1 bank x 20 voices
Connection terminals and interfaces
Output Phones (phone jack)
Control jack: foot switch, foot control
MIDI IN, MIDI OUT, MIDI THRU
Dimensions and weight
101.8w x 10.2h x 32.9d (mm) / 40” x 4” x 13”
12.4Kg / 27.4lbs
Yamaha DX9 Owner's manual
To get yourself started with this machine, you might want to check out the manual. Of course, real collectors have the original copy of the DX9 manual in pristine condition, but they're quite hard to find at reasonable prices. You don't really want to get a real DX7 and then read the pdf manual on your smartphone don't you?
Fortunately, to support this website you can now buy a copy of the reprint of the Yamaha DX9 manual. The manual, just like the original, comes with its own "performance notes" booklet, an even rare object to buy nowadays.