The business of getting electric guitars to control MIDI instruments has been fraught with problems, most commercial attempts in that direction being both expensive and only partially successful. A lower cost approach is that adopted by Shadow in their SH075 unit, which can be fixed to most electric guitars, including Strats and their many clones. The system comprises four parts: a six-pole, slimline pickup which picks up all six strings separately, the converter, which is also the control unit, a small junction box with a MIDI output socket, and an external power supply which provides the low voltage to drive the system. The pickup attaches to the guitar as close to the bridge as possible, while the converter can normally be fixed via the strap peg on the end of the guitar body.

Working on the pitchtracking system, the convertor unit processes the output from each section of the pickup, extracts the fundamental pitch from the harmonics and then converts the pitch to MIDI information. This happens very quickly, but there is a perceptible delay when playing the bottom two strings of the guitar. This is less noticeable if you are also using some of the basic guitar sound at the same time.

The various numeric buttons plus the three LEDs on the converter unit allow the guitar to be tuned, and also enable the user to send MIDI program change messages (0-99) to external equipment. Both Poly and Mono MIDI modes can be selected, while MIDI pitch bend can be enabled or disabled. In Poly mode, the unit sends on MIDI channel 1 only while in Mono mode; the six strings are split over MIDI channels 1 to 6, with the first string being assigned to channel 1. The pitch bend range can be selected as either 8 semitones or 4 semitones, and it is essential that the receiving synth be set to the same range or the result is likely to be seriously unmusical! The MIDI output from the unit may also be transposed up or down by up to three octaves. To keep things tidy, provision is made to send the regular guitar signal down the multicore DIN lead which joins the convertor to the junction box.

Before using the unit, the individual string sensitivities need to be set up to suit the user's individual playing style, and this is accomplished using the six screwdriver presets accessible through holes in the front of the unit. This is a simple procedure and is adequately covered in the instructions. Two rotary knobs allow the user to control the velocity of the MIDI output (MIDI Volume) and the dynamics of the MIDI data. On its minimum setting, the Dynamics control causes all notes to be at the same level, while at maximum the dynamic range of the signal is probably a little excessive for most purposes. A setting close to the centre is usually most effective.

Once set up, the unit functions surprisingly cleanly, providing you play carefully and don't expect it to respond to speed metal or sloppy playing. Over-heavy picking causes the odd spot of double triggering, which is noticeable on percussive sounds but less so on slow-attack sounds such as strings and choirs. The delay on the bottom string can also be a nuisance when you're playing quickly but, as previously mentioned, putting some of the straight guitar sound through the monitoring system helps you keep time.

The unit is most stable with the pitch bend mode turned off, because then all notes are quantised to the nearest semitone. It is possible to use it with the pitch bend on, but then the guitar needs to be very well set up and played very carefully. It is also an advantage to be in mono mode if using pitch bend, as this allows each string to bend independently of the others. Of course, this requires the use of a synth that works in mono mode, but many do. Failure to select mono mode means that bending any one string will cause all the notes currently playing to bend together.

Though by no means perfect, this little gadget has no more shortcomings than some systems costing three or four times as much, and it can be fitted to virtually any guitar. It is ideal for use with a sequencer, because small timing errors can be corrected using quantisation, while low velocity or duplicated notes can usually be edited out automatically. For the guitarist with a home studio setup, the Shadow SH075 provides a straightforward and cost effective means of gaining access to all the sounds available to today's keyboard players and, given the low starting price of MIDI keyboards and sound modules, this has never been a more attractive avenue of exploration. If you feel the need to get out of a musical rut, this could be your chance!

Further Information
Shadow SH075 £299 plus power supply, including VAT.

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