A spiritual healing aid with special powers for technologically challenged? A new fangled night-light for those burning the midinight oil? In fact the MIDI Crystal is a neat little visual indicator which lights up whenever MIDI signals are passed through it. Just the thing if you really want to get in touch with your MIDI data, like er... you know, man?

It's a small red 2½" tube filled with electronics and a LED. It has MIDI sockets on both ends so you just plug it in-line between a couple of MIDI cables. It doesn't appear to interfere with the data flow at all. It responds to Note On, Note Off and Controller messages (bright flash); Pitch, Mod Wheel and Aftertouch data (rapid flash); Active Sensing (3-5 flashes per second); SysEx data (steady bright glow); and MIDI Clock signals (steady dim glow).

Of course, if your system happens to send all these at once you won't have an earthly as to what's going on. But it looks pretty and you can use it as a diagnostic aid to help locate faulty MIDI cables - no flashes for you tonight - and check that a device is actually transmitting data when it's supposed to be. In fact it has already saved me from dismantling my system simply by proving that signals were actually going into an expander when I'd convinced myself they weren't (blush... I'd turned the bloody volume down on the unit rather than on my mixer!). I've also used it as a MIDI-to-MIDI cable connector. One of my cable runs is quite long and the dog, short of postmen, had chewed through one of the cables. And guess who didn't have a spare long enough?

The Crystal would offer more of a psychedelic display if it used different coloured LEDs instead of just the one, but that would probably have put a bigger drain on the power consumption and maybe add to the cost. As it is, it only requires 3% of the MIDI line power - a reasonable overhead.

All in all, the MIDI Crystal is a useful little gizmo; well worth having to hand if you ever experience MIDI communication problems. And who doesn't?

THE LAST WORD