This is an amazingly cute 64-voice synthesizer by Roland, introduced in January 2001. It's the smaller brother of the RS-9, with just 61 keys instead of 88. Unlike most other synths, it looks pretty, which is due to the neat brushed-aluminium front panel.
It's more or less a 'budget' machine -- it retails at less than 900 euros, while I got mine used for less than 700. People tend to either love this synth because hardly any other machine gives you as much sound for the buck; or they hate it for the limited editing. Come on, folks! It's not like it's pretending to be virtual-analog.
The RS-5 features 512 patches --that is, 256 plus the usual General MIDI bank-- drawing from a whopping 32 mebibytes of 16-bit linear equivalent wave memory. They're grouped into categories so chosing a sound is much easier than with many other comparable machines (such as the Korg X5D). The strong side are the many different E piano, analog synth and other classic keyboard patches. People seem to like the orchestral patches, too, but I don't use those.
A patch ('tone'), together with parameters such as a MIDI channel assignment, makes a 'part'. Via MIDI, a maximum of 16 parts can be played at once (whooo); from the keyboard, you can only play two, either at once (layered) or from the upper resp. lower zone of the keyboard (split).
Postprocessing of the sound is done, either partwise or all parts at once, by a great multi-effects processor ('MFX') that can do wonders to the sound. I like especially the flanger and overdrive effects. For the overdrive, you can even select the type of amp cabinet you want the RS-5 to simulate! After the MFX, dedicated chorus and reverb units complete the sound-processor lineup.
There's also a very neat arpeggiator, something dance musicians will love. It can play the notes you're holding down in countless different patterns and feelings. This is not some kind of mindless single-finger accompaniment section -- it just does stuff with the notes you actually play.
I forgot: There's a filter, too; cutoff and resonance can be controlled by two knobs on the front panel. Just don't ask me for the filter's dB value.
A single saw-wave LFO is on board, too; it can either control the filter cutoff or modulate the pitch. Four more knobs control LFO depth, LFO frequency, attack time and release time; a three-way button can switch them over to control the arpeggiator's parameters or serve as freely configurable controllers.
This is where the RS-5 really shines: you can program those four knobs to control anything, and a 'control' jack takes input from a foot switch or expression pedal you can use as a fifth value. An example: A split setup with classic analog pad/lead sounds; the first knob controls the volume balance between the upper and lower parts. The second knob regulates the overdrive; the third knob the 'Chorus Send' level so you can add in chorus to taste; and the fourth knob the 'Reverb Send', to do the same with reverb. Your expression pedal is hooked up to the control jack and, controlling the cutoff frequency of the filter, serves as a wah. This is a lot of twiddling from a machine that costs you less than 900 euros new!
Let me conclude: I love my RS-5. Thanks for your attention.
(BTW: As it's so 'budget', you won't find superstars endorsing the RS-5 -- for their bread-and-butter, people with much money tend to go for hyper-featureful workstations such as the Roland Fantom, Roland XV series, Korg Triton, Korg Karma or Yamaha Motif. However, there are at least two dance/electronica acts called AEPOC and SKR Team that use this synth.)