Roland's first stand-alone touch sensitive synthesizer is a revolution in sound and technique, Alan Townsend set out to explore what the unique touch system means in practical terms.

When you sit down to play the JX-8P the first impression is of an unusually responsive key action. Unlike other synthesizers, even touch-sensitive ones, the JX-8P is equipped with small lead inserts which counterbalance the key action and give a 'live' dynamic feel. This weighted keyboard brings out the best in the technical capabilities of the instrument; the vast range of sounds which can be altered and modified purely by the speed and pressure at which notes are played.

To those familiar with conventional instruments, the most obvious difference when you start to play the JX-8P is that its touch-sensitivity allows a creative balance between the right and the left hands. Play a block chord on an ordinary synthesizer, and it will swamp a single note melody played higher up the keyboard. With the JX-8P the volume and quality of the left hand chords is varied according to how hard you play. Select a piano voice, for example, and the full expression of piano technique can be used. Taking things a stage further, since major parameters of synthesis can be linked to the velocity sensing, a whole spectrum of different sounds can be produced according to how the keyboard is played.

Touch sensitivity in the JX-8P allows sounds to alter according to changes in either velocity or pressure. Using the pressure sensing vibrato can be introduced just by holding down a note or chord and pressing harder. Full brass chords can be made to 'throb' by this means. And the player's instinctive tendency to emphasize the melodic part of a piece and play down the accompaniment allowed full reign.

Pressure sensitivity, however, can do more than just trigger the LFO. It can be linked to various functions and unlike velocity control can be applied at any time during the note. It can be applied to the filter for interesting harmonic changes and filter sweeps at the touch of a finger. Also, of course, it is linked to the VCA so that more pressure means more volume. Using the pressure sensitivity controlling volume, filter, pitch and vibrato in various degrees the JX-8P becomes an instrument of unbelievable subtlety and power. Electronic instruments, once thought of as clinical, are now even more effective than acoustic ones in terms of being able to express emotion and emphasis in an immediate, tactile way. Putting it in different words, with the JX-8P the keyboard player can get physical.

Altered States

In the JX-8P, Roland perfect the 'interface' between an electronically produced sound and a flesh-and-blood produced creative inspiration. Pressure sensitivity is one way of doing this, but the keyboard also reads the velocity at which each individual key is hit. (When products are advertised as touch sensitive it's always worth checking whether this means individual keys — or the keyboard as a whole). Velocity information can change volume, tone, and pitch. A piano or drum tone changes harmonically according to how the instrument is played, and this can be duplicated on the JX-8P. Volume changes according to how hard individual notes are played give a natural, human sound to the instrument. The link to pitch can be used to produce a subtle inflexion or something bizarre — a good demonstration is to use this facility to duplicate the Syndrum sound.

A Touch of Sync

Two banks of oscillators are provided on the JX-8P and unusual effects can be achieved using phase synchronisation linked to the touch sensitivity. Phase synchronisation involves the formation of complex wave patterns by setting two oscillators to a different pitch and then timing DCO-2 to re-start its wave cycle each time DCO-1 does. Since (for example) a saw-tooth wave generated in this set-up by DCO-2 therefore tends to get stopped and re-started at an arbitrary point in its cycle, it ceases to be a conventional sawtooth wave and generally ends up a fairly odd shaped wave with correspondingly unusual harmonics. Because the phase synchronisation can be linked to the velocity the hard, metallic effect of the phase interaction can be brought in only when you hit the keyboard hard. This technique is a valuable way of giving a real edge of lead sounds. Cross modulation and ring modulation can be accessed in the same way — linking bell and chime effects to the touch response.

Voltage Controlled Mix

Perhaps the most revolutionary feature of the JX-8P is the voltage controlled mixing system which enables the velocity sensing circuitry to control the balance between DCO-1 and DCO-2. The most impressive demonstration of this is to use the factory Flute sound. Play the keyboard gently and the JX-8P gives a soft, pleasing flute tone. Play harder, the DCO-2 is brought in by degrees until there is a really strong 'over-blowing' sound just as there would be on a real flute. With the JX-8P it is for the first time possible to re-capture accurately the way almost all acoustic instruments change their sound quality according to the way they're played, not only in terms of volume but in terms of brilliance, envelope, pitch, noise content and so on. Another useful effect on the voltage controlled mixer is to tune DCO-2 to a fifth, and then use the velocity sensitivity to bring the fifth in as the keyboard is played more aggressively.

Since the JX-8P has not one but two envelope generators DCO-2 can also be set to a different envelope from DCO-1. In this way quite different attack, decay, sustain and release characteristics can be obtained for each oscillator. Many acoustic voices never sound realistic until they have a slight percussive content, and by creative use of the twin envelopes and the dynamic control the JX-8P can create acoustic sounds as realistic as any synthesizer ever made, without sacrificing the fundamental warmth of analogue sound or user-friendliness in programming and control.

The concept of the JX-8P is simple. The best sounds don't come from electronic circuitry, they come from human musicians. Only when sound is intimately and completely linked to the player's technique can the variety, subtlety and expressiveness of a virtuoso instrument be attained. Of all synthesizers regardless of type and price range, the JX-8P offers the best 'interface' between creative musician and sophisticated sound circuitry.