KORG microKEY-25 review

The original KORG microKEY-25 is a 25-key USB-powered MIDI controller with Natural Touch mini keys, a joystick, an arpeggiator button and Sustain/TAP control. It is a different generation from the later microKEY2 and a different product from the Bluetooth microKEY Air. Its concise layout is attractive when a small note-entry surface is the task; it is not a USB-C or direct-DIN controller.

Identify the original model first

KORG’s U.S. product and specification pages call this family microKEY, and enumerate 25-, 37- and 61-key configurations. The 25-key model has its own controller layout: a joystick, arpeggiator button, Sustain/TAP button and octave-shift buttons. The 37- and 61-key models instead use separate pitch-bend and modulation wheels and add two downstream USB-A ports. Those differences are one reason not to borrow facts from a neighboring size or a later microKEY2/Air listing.

The keys are called Natural Touch mini keys, and the English owner manual describes the 25-key keyboard as velocity-sensitive. KORG’s feature page explains eight velocity curves plus a constant-velocity setting. It does not specify key aftertouch, individual key dimensions or a weighted action. “Natural Touch” is the manufacturer’s keybed name; it cannot predict how a particular person will find the mini keys. If note spacing is decisive, see or verify the exact model rather than inferring full-size key dimensions from marketing wording.

Compact range and body size

The 25-key version measures 395 × 131 × 53 mm, or 15.55 × 5.16 × 2.09 inches, and weighs 0.65 kg. The width falls below the finder’s smallest 16-inch body cap, but a 0.45-inch margin is not enough to plan a complete desk position. A USB plug, cable bend, hands and a stable support all take space beyond the bare dimensions.

Twenty-five physical notes make it the most compact member of this original family. The octave buttons can shift the range from −4 to +4, while the feature page says the key-transpose function can reach across the MIDI note range. Neither function creates more keys that can be played simultaneously. If the intended part needs broader two-handed voicings, look at the 37- or 61-key model rather than treating transposition as a substitute for a larger bed.

On this model, the joystick is the main continuous gesture control. The arpeggiator button and Sustain/TAP button add a small performance vocabulary without the wheel pair on the larger sizes. There is no drum-pad bank or panel of knobs. No separate pedal input, USB-A hub, USB-C connector, Bluetooth MIDI, direct five-pin DIN or audio output is documented in the reviewed 25-key materials.

One USB host connection

KORG specifies one USB Type-B connector and USB bus power below 100 mA. That single computer link carries MIDI and powers the keyboard; no separate adapter is listed as necessary for the documented computer setup. The original microKEY does not connect straight to external five-pin MIDI gear, so a computer or a separate MIDI host/interface must provide that route. The keyboard itself has no sound engine or audio output; it sends MIDI messages to software or an external sound source.

KORG’s feature page describes older iPad use. For the 25-key size it names Apple’s Camera Connection Kit and a USB cable; the same page warns that operating-system updates can affect compatibility. That is historical setup guidance, not a claim that current tablets or apps will work. The owner manual likewise lists legacy operating-system baselines and states that functionality is not guaranteed on every computer satisfying them. Check today’s KORG driver/support page and the MIDI behavior of the exact host app before relying on an older unit. The presence of a USB port does not itself establish support for a particular DAW or tablet.

What a listing still needs to prove

The product page’s bundled-software language is not proof that a used unit includes a valid, unused, transferable code. Confirm the actual cable, package and condition with the seller. No inspected source ties a retail SKU or current price/stock to a particular unit. The original model name also matters: a listing titled “microKEY” may be imprecise, while microKEY2 and microKEY Air have separate specifications and wireless options. Match the case, control layout, connector and key count against the exact 25-key configuration before applying any model-specific assumptions.

For a small, velocity-responsive MIDI input with a joystick and software arpeggiator control, the microKEY-25 offers a clear USB-powered plan. Its limitations are just as clear: mini keys, a short simultaneous range, no documented direct DIN, no USB-C and no audio. It is a sensible shortlist candidate only when the host connection and key format match the actual setup—not because a seller’s generic “MIDI keyboard” title establishes compatibility.

Research sources: KORG microKEY product page; features; U.S. specifications; support and downloads; 25-key Owner’s Manual.