M-Audio Keystation 88es

Digital MIDI Controller Keyboard

This 88-key board was acquired to serve as a MIDI controller for the Modular Synth, which is its usual purpose. Unfortunately, the Synthesizers.com Q104 MIDI interface module only has a 61-key range of C1 to C6 (which I did not realize beforehand), so above and below that, lower or higher octaves are repeated (i.e. the C#6 key plays identical to C#4). It also has a USB attachment, so it can function as a controller for software "instruments" as well, which seems to be the main market for it.


  • 88 full-sized velocity sensitive, "semi-weighted" (i.e. not weighted) keys (A-1 to C7 / 7 octaves + minor 3rd, same as most acoustic pianos)
  • pitch-bend wheel
  • "modulation" wheel (assignable to various functions)
  • "volume" slider (assignable to various functions)
  • octave +/- buttons (assignable to various functions)
  • "advanced function" button (used to assign functions and alter parameters)
  • 5-pin DIN plug for MIDI output
  • square USB plug for USB MIDI connection to a computer
  • 1/4" jack for sustain pedal
  • jack for DC adapter (9V DC, center pin positive)

The Hardware

This keyboard follows modern trends of keyboard design in that it is mostly made of plastic. As well, there are so many screws on the underside that I didn't think it was worth opening to show the insides, which I'm guessing would consist of very little of interest aside from a circuit board with a microcontroller. I have not been able to find a service manual, which is not surprising considering that this unit is very clearly not designed to be serviced. It is able to be powered either by a USB connection to a computer (it comes with a nice long USB cable) or with an external 9V DC supply (center positive), but if you buy the unit new, it does not include a DC adapter, presumably because they expect most people to be using it for software "instrument" control.

The keys, like those on most modern digital keyboards, are velocity sensitive, and are piano-styled (the naturals have full-height fronts with an overhang, and the tops of the sharps are of even height). Now, while the manual states that they are also "semi-weighted keys that give you the feel of a piano", everything about this statement is false; they really aren't weighted at all (by any usual definition), and feel considerably different than the keys on a piano, due to the very different opposing force that the keys exert over the distance of the keypress. They are just standard spring-loaded organ-type keys with particularly stiff springs, which makes it considerably more difficult to play fast and complex runs, as well as play for extended periods of time comfortably. Maybe they're alright for slow chordal things, especially without the black keys involved since they seem to be stiffest (also since the pivot point is very close to the playing area), and apparently some people like the feel of them. In my opinon though, it would be great if the usual soft springs found on most modern digital boards were employed.

Editing the functionality of the keyboard is done with the "advanced function" button and, since the keyboard has no screen or keypad, the keys themselves. The process is described in the owner's manual, which is a good thing because it is so unintuitive and poorly indicated on the board itself that figuring it out otherwise would be exceedingly unlikely. As of yet, I have not experimented with much of this editing functionality, especially since much of it concerns MIDI information that is of no relevance to the modular synth's MIDI Interface module (such as MIDI channel and instrument/program change), but I suggest looking at the manual (available at the bottom of the page) if you're interested in doing so yourself.

Despite these criticisms, this keyboard does have some nice features that are useful for modular synth playing. First of all, the octave buttons allow the 61-key range of the MIDI control module to be shifted up or down a maximum of 3 octaves on the board to whatever position is convenient. For example, if I was experimenting with modules towards the left end of the synth, I may want to shift the keyboard an octave downwards so as to have the range in convenient playing position relative to the part of the synth being worked on. As well, the pitch bending wheel is large and rotates smoothly, and with some "advanced function" trickery, can be adjusted to have a range of 2 octaves (1 up, 1 down).

Downloads & Links

Keystation 88es on the official M-AUDIO website

Owner's Manual

If you notice any errors or have additional information that you would like to add, please contact me!

Last Updated: 4/27/2015