According to Vintage Synth Explorer, this analog synth was made between 1979-1980. Like other synths of this type, it's incredibly warm-sounding and also incredibly noisy. It also looks really, really cool, like a prop from Blade Runner or 2001.
Like it says on the dashboard, it does Organ and String sounds. Neither one are very realistic, but both have that distinctive, grainy harmonic character associated with the best synth tones. Dialed with lots of high-end it can sound a little buzzy, but it also takes EQ extremely well. The Organ side can do super-sparkly glassy chords or fat Wendy Carlos leads. The Strings side is pretty grainy and sawtooth-y; it sounds very much like a Joy Division-style post-punk synth but is a little too harsh to mimic actual strings on less aggressive music styles.
The two voicings don't share many tone options - the Organ side has a 4 band EQ which is really more of a tone-shaping control, while the Strings side has two separate voicing options and an attack/release envelope. Both have their own Ensemble rocker buttons, which produce an effect similar to chorus but a little phasier and weirder.
There's also a mode button which (on my unit at least) switches between regular polyphonic mode and a sort-of-monophonic mode where the sustain cuts off on certain note attacks. It's hard to explain...but oddly useful. Also a tuning knob, which is a little tougher to operate than the rotary-style tuners on other Roland units like the Juno 60, but still useful for doing pitch-shifting "glide" effects. Messing with any of these tone options is going to produce a big shift in the keyboard's sound, which is helpful in getting creative but also makes it tough to dial in anything subtle.
I forget exactly how much I paid for this but I don't think it was more than $300 or $350. (Shout out to Switched On!) While it's not the most versatile synth in the world, if you dig its sound you might find yourself incorporating it into your writing or arranging process quite a bit. The handful of sounds it does, it does really well, and it's definitely a looker. A little heavy for its size but also fairly portable if you can find a case for it (good luck). Anyone interested in ambient synth-related music should definitely check it out.
Actually one of the best string synths around. Great organ tone also. Huge sounding Roland Chorus. Sounds massive in stereo, and also in mono. Can process external signals with the chorus which is a nice obtion to have.. It is noisey, but you can just strap a Denoiser or Hush after it. With a little reverb or delay the unit takes on another level. The one thing that really stands out is the seperate modes for the envelope section on the strings. The one mode is like an overlapping of notes that is like no other synth I have ever played. It the best thing about the RS -09. You need to use a certain style of playing the keys to make the most of it. If I was to have just one string machine, this would be it.