Alesis Photon X25

A compact controller keyboard can both send MIDI commands and exchange audio signals with a computer. The 25-note velocity-sensitive keyboard of the Alesis Photon X25 is combined with a 24-bit stereo audio interface. It is suitable for controlling music software and for recording or playing back audio signals via USB.

For MIDI control, ten endless rotary encoders are available, which you can assign across three independently selectable layers. This allows up to 30 encoder assignments per preset. Ten programmable buttons can be configured as switches or as momentary buttons. In addition, the AXYZ dome controller detects movements left and right, up and down, as well as the distance of your hand, and converts them into three MIDI control axes.

The pitch and modulation wheels are illuminated; you can shift the keyboard range using the octave buttons. The velocity curve can be adjusted via the global settings, as can transposition by up to ±11 semitones. A two-line LCD displays status and settings. The encoder is used to select and confirm parameters, while the control buttons cover preset selection, editing and global settings.

The integrated audio interface transmits stereo audio at 24 bit and up to 48 kHz via USB. You can adjust the input and output levels separately on the unit. Analogue stereo inputs can capture signals from a mixer or synthesiser, for example; the stereo outputs route computer audio to a mixing desk or active monitors. A headphone output is also available. Direct input monitoring can be enabled in the Global menu, without first routing the signal back through the computer.

The keyboard sends and receives MIDI via USB; five-pin MIDI IN and MIDI OUT sockets are also available. The MIDI connections can be active at the same time as USB. When USB is connected, the MIDI output passes on data from the computer; without USB, it sends the notes played on the keyboard. Separate connections are provided for sustain and expression pedals. Power is supplied either via USB, four C-size batteries or an external 6 V DC power supply rated at 1,000 mA with a negative centre contact. Twenty storable presets save your own controller configurations.

The Photon X25 is suitable for a mobile or fixed setup if you are looking for a small MIDI keyboard with rotary encoders, three-dimensional control and audio I/O. For computer operation, the documentation specifies Windows XP or Mac OS X and USB 1.1 or higher; compatibility with current operating systems is therefore not guaranteed. USB, MIDI and pedal connections cover a range of control and connection scenarios.