M-Audio Oxygen 25 (MKV) review

Oxygen 25 (MKV) is M-Audio’s compact 25-key controller in the Oxygen V generation: full-size, velocity-sensitive keys, eight physical pads in two banks, eight knobs, one fader and USB MIDI control. It is a computer-focused controller, not a self-sounding keyboard. This assessment follows the manufacturer’s model page and manuals rather than a playing test.

Decide whether 25 physical keys are enough

The central tradeoff is straightforward: a short bed keeps the instrument small, but octave buttons cannot turn it into a larger keybed. They shift the notes available to the keys and pads; they do not let you hold a low bass note and play a distant melody simultaneously. For short parts, a small desktop footprint, or inputting a phrase one hand at a time, 25 full-size keys can be a practical range. For broad two-handed passages, repeated octave changes may become a workflow interruption. The 49-key and 61-key Oxygen V models add real physical span, but they also take substantially more width.

M-Audio lists the 25 MKV at 19.3 inches wide, 9.6 inches deep and 3.7 inches high, weighing 4 pounds. The maker calls the keys full-size and velocity-sensitive; the consulted page and manuals do not specify a weighted action, force curve, key travel, or aftertouch response. Those details should remain unknown rather than being filled in from the Pro family or a photograph. The published body width is only a first desk check. A USB plug, cable bend, hands, stand support and optional sustain pedal need their own space.

A compact control surface with one fader

The page describes eight assignable knobs and one fader alongside eight velocity-sensitive pads, transport controls, a display, pitch and modulation wheels, Smart Chord and Smart Scale modes, an arpeggiator, and Note Repeat. The pads are eight physical surfaces selectable in two banks, not sixteen pads available at the same moment. That distinction matters if your drum routine depends on many simultaneous pad positions.

The one-fader layout is the clear size-specific compromise. It gives a compact controller a tactile level control, while the 49- and 61-key siblings provide nine assignable faders with the same eight knobs and eight physical pads. The larger models therefore suit routines where multiple track levels or a wider hand position matter; the 25 remains the more compact keybed, not a miniature copy with identical control counts. The Oxygen Pro 25 is another distinct product: its reviewed panel has a different pad/fader configuration and direct DIN output. Do not assume those Pro features belong to the MKV because the names are similar.

USB MIDI means a host-centered setup

The MKV quickstart describes a USB 2.0 connection that both powers the keyboard and carries MIDI when connected to a computer. The pictured rear socket is USB Type-B; the manual recommends an onboard powered USB port or powered hub. M-Audio’s support FAQ calls the family class-compliant and says it uses the computer’s core MIDI drivers. That lowers one setup hurdle, but it does not make every DAW mapping automatic: the quickstart still walks through choosing the controller ports and selecting a software instrument.

The exact rear-panel guide lists USB, a sustain input, power switch and Kensington lock. It does not list a five-pin DIN MIDI Out or MIDI In, so a direct cable to a DIN-only hardware sound module is not the documented arrangement. MIDI sent over USB to a computer can trigger a software instrument there; a separate interface/host would be needed to create a different hardware route. The product is not an audio keyboard with an onboard sound generator, and the sound source’s audio monitoring remains outside the controller.

Check the model and package before choosing an offer

Confirm that the listing says Oxygen 25 (MKV) or Mk V, not Oxygen 25 MK IV or Oxygen Pro 25. These are separate product generations, and the name alone is not enough to infer the ports, control layout or manual. M-Audio’s listed contents are the controller, USB cable, software download card, quickstart guide and safety/warranty manual. A sustain pedal is not listed; promotional software claims should not be treated as confirmation that a used unit still has an unused registration code or that a seller includes every listed item.

Choose this model when 25 physical full-size keys and a small body are useful, the one-fader surface is sufficient, and a USB-connected computer or compatible host is already part of the plan. Look elsewhere if the essential requirement is direct DIN routing, a verified pressure-sensitive pad, a documented weighted action, more than 25 simultaneous physical keys, or built-in sound. Before ordering, check the exact MKV suffix, cable and software-card status, return terms and space around the body. The review does not claim ownership, hands-on use, measured key feel, reliability testing, current stock or price.