A slew of inexpensive, compact combination MIDI and audio interfaces from a variety of manufacturers has recently hit the streets. Alesis's contribution to this embarrassment of riches for laptop musicians is the Photon X25 — an audio interface and two-octave, Velocity-sensitive keyboard with an interesting assortment of MIDI controllers.
FIG. 1: The Photon X25 sports full-size keys, ten user-configurable buttons and endless rotary knobs, oversize Mod and Pitch Bend wheels, and a 3-D Dome controller.
The Photon X25 is a USB device that can be powered by bus, battery, or optional wall-wart power supply. For portable use, battery power is a welcome option because a laptop computer running on its own batteries is unlikely to provide adequate USB power. Alesis claims a set of batteries (four C cells) will provide power for five or more hours, and during the course of this review, I got considerably more.
Driver installation is generally unnecessary under Mac OS X and Windows XP; installing the provided ASIO audio drivers, however, is recommended for Windows. (Earlier versions of Windows and Mac OS are not supported.) The X25 was truly plug and play for audio and MIDI on my Mac PowerBook and my Power Macintosh, but I had some initial trouble getting the unit recognized on my PC laptop. The X25 was eventually recognized (after several power cycles), and at that point I was able to install the ASIO audio drivers and had no further problems.
The MIDI Ditty
Although a two-octave keyboard has its limitations, the X25's keys are full size and have a good, solid feel (see Fig. 1). The keyboard is comfortable to play, the octave-transpose buttons are conveniently located for easy access and, in a nice touch, the buttons light at different intensities to indicate the current transpose.
Translucent rubber Pitch Bend and Modulation Wheels to the left of the keyboard also feature variable-intensity illumination, though it's hard to imagine what purpose justifies the added power consumption. The wheels are larger than usual and offer just enough resistance to make them easy to position accurately. I'd love to have these wheels on my 88-key controller.
The X25's variation on the joystick is a proprietary Axyz Dome Controller that senses the up-down (distance), right-left, and forward-back position of your hand while it's over the Dome and sends out values for three different MIDI controllers in response. Although not easy to control accurately, it does have a certain novelty value, and it can be turned off to save power as well as avoid accidental controller changes.
Making the Rounds
Ten user-assignable buttons located above the keyboard are handy for toggling virtual-instrument and -mixer buttons. They're also a viable substitute for hardware pedals when you're on the road — you can develop sustain-pinky chops in fairly short order. The buttons can be conveniently configured in toggle (press on, press off) or momentary (press on, release off) mode.
Ten endless rotary encoders (aka 360-degree knobs) and three independent settings layers provide ready access to 30 MIDI Control Change settings. Unfortunately, the encoders do not implement one of the common increment-decrement schemes nor is feedback supported. That means that when you change assignments, the old knob value is retained, and the new target parameter will jump to that value.
Nonetheless, endless encoders are an enhancement. One reason is that they have higher resolution; it is actually possible to increment their value one step at a time. Another reason is that the layering scheme can support 30 distinct values rather than the much-less-useful 10 distinct values that would be possible with standard knobs.
Presets and Resets
The X25 has a 20-preset memory for the configuration of all knobs, buttons, and other controllers. The unit I received contained 13 factory presets covering a variety of software products, including digital audio sequencers Steinberg Cubase LE (a copy of which is shipped with the unit), Cakewalk Sonar, MOTU Digital Performer, and Ableton Live. Software instrument presets cover several Native Instruments products, Applied Acoustics Lounge Lizard, and most of the modules in Propellerhead Reason.
Cardboard templates for insertion on the X25's front panel are provided for each of the factory presets, including the default preset resident in memories 14 through 20. All of the templates I tried, including the default, unfortunately had inaccuracies. But because the templates are difficult to install and read, they probably won't get much use, and you'll quickly memorize the presets that you use the most.
In addition to preset configurations, you have access to several global settings. Those include contrast for the 2 × 16 LCD display, Velocity curve for the keyboard (linear, logarithmic, exponential, and constant), semitone transposition, and direct audio-input monitoring.
The X25 offers several MIDI utilities. You can send and receive SysEx dumps for individual presets or the whole preset bank. You can send MIDI Program Change messages with or without bank. And you can send a MIDI All Notes Off command (which usually kills hung notes) by simultaneously pressing the Page-Up and Page-Down buttons.
Now Hear This
The X25 features a basic but excellent-sounding USB 1.1 audio interface. It supports balanced and unbalanced stereo I/O at 44.1- and 48 kHz sampling rates with 24-bit resolution. All audio I/O uses ¼-inch TRS jacks, and headphone as well as main outputs are provided. Front-panel knobs control output level and input gain (to a maximum of 30 dB), and the input can be routed directly to the output for no-latency monitoring.
I plugged the X25 into a Macintosh G4 PowerBook and a Windows laptop and, running all units on battery power, was able to push the computers to their processing limits without experiencing any audio dropout. The signal was clear and clean in headphones and through my mixer and monitors.
In addition to USB MIDI I/O, the X25 sports a second MIDI interface, allowing it to communicate with other MIDI hardware. MIDI input is passed to the computer on a second MIDI port, and USB MIDI output from the computer is sent to the MIDI output jack. In a nice touch, if no USB is connected, the X25's MIDI is passed directly to the second output jack, allowing the X25 to function as a standalone MIDI controller.
The Photon X25 is a well-endowed and reasonably priced MIDI controller and audio interface for the portable studio. It's rugged, well engineered, and ergonomically laid out. It may not be as full-featured an audio interface as you would want in a desktop studio, but it makes a great auxiliary MIDI controller in that environment.
Len Sasso is an associate editor of EM. He can be contacted through his Web site atwww.swiftkick.com.
PHOTON X25 SPECIFICATIONS
MIDI Keyboard 25 notes MIDI I/O (2) USB and DIN Controller Inputs (2) TS (for pedals) Rotary Encoders (360°) 10 Buttons (toggle or momentary) 10 Wheels (2) (Modulation and Pitch Bend) Axyz Dome 3-D Audio Outputs (2) balanced/unbalanced TRS Audio Inputs (2) balanced/unbalanced TRS Headphones Output (1) stereo TRS Display 2 × 16 LCD Power USB, battery, wall wart (optional) Dimensions 18" (W) × 3.5" (H) × 9.5" (D) Weight 4 lbs.
USB keyboard controller and audio interface $299
OVERALL RATING (1 THROUGH 5): 3
PROS: Rugged, ergonomic design. Simultaneous access to 30 MIDI controllers with high-resolution, 360-degree rotary encoders. Clean and efficient USB audio performance.
CONS: Rotary encoders don't support any increment-decrement scheme.