Roland JX-10 Super JX Polyphoic Synthesizer

click on JX10 for larger picture

The JX-10 was released in 1986 at a list price of $2750. Its a 12 (24 oscs) voice unit that features two independent six voice, velocity and pressure sensitive synthesizers. Each one of these synthesizers is essentially the same sound engine used in the JX8P. It can operate as a single 12 voice unit or 2 separate six voice units capable of splits and layers. It was Roland’s last analogue keyboard (though it does use DCO’s). FM synthesis (basically anything by Yamaha) was the hype back them and the use of transient attacks in conjunction with standard waveforms still hadn’t been introduced yet under a wonderfully conceived name, courtesy of Roland’s marketing department, of Linear Synthesis. While it does a few things that you couldn’t do using two JX8Ps, it doesn’t do some things that you could do with two JX8Ps. For the individual voice structure see the JX8P.

The keyboard is 76 key unit that has a nice amount of firmness to it. The firmness allows you to still play flying leads but also to make good use of the velocity sensitivity of the keyboard. I use the JX-10 as my master keyboard. Velocity can used to modulate a number of items. Unfortunately the unit only features four velocity scales for the user to choose from. The keyboard is also aftertouch sensitive, however it is monophonic (for each synth engine) and maybe routed to control volume, filter, and LFO only.

The machine has two level sound architecture to it. The first and basic level of a sound is called a tone. The second level is called a patch and consists of two separate tones. The units internal memory holds 50 tones in ROM which may not be replaced and 50 in RAM for a total of 100 tones. The unit holds 64 patches which consists of two tones. Since the patches are comprised of one or two tones as you edit tones you will affect any patch that uses the tone that you are editing. Each patch may bed named using up to 16 characters and each tone upto 10 characters. The machine operates in 6 key modes as follows:

Up Whole - The JX operates as a 12 voice monotimbral synthesizer with the upper tone in the patch selected as active.

Lo Whole - Same as up whole but the lower tone in the patch selected is active.

Dual - This mode turns the unit into a six voice synth with both the upper and lower tones playing simultaneously. (That’s four osc per voice). The dual mode also features a detune parameter which gives that beating fatness.

Split - This mode splits the keyboard (user chooses the split point) into upper and lower sections where a different tone is used in each section. What really nice is that the upper section may have it own lowest key and lower section may have its own highest key leaving a middle section that will drive a external synth.

Touch Voice - This mode will play either the upper or the lower tone depending how hard the key is played.

Cross Fade - In this mode the volume of the lower tone decrease as key touch strengthens and the upper voice decreased as the key touch as key touch weakens.

A really nice feature of the dual mode is chase play which creates delays between tones in the dual mode. The chase play section has three modes as follows:

ULU - the upper sound is played first followed by a programmable delay then lower sound is played. This is repeated until both sounds die out.

ULL - the upper sound is played first followed a programmable delay then the lower sound is played followed by the delay and the lower sound is repeated unitl it dies out.

UL - the upper sound is played first followed by a programmable delay then the lower sound is played. Neither sound is repeated.

Since each synth engine has its own output you can pan each sound in opposite directions and get some really cool ping pong delay effects. Bottom line on chase play is its excellent.

The unit features four output jacks for stereo output of each synthesizer unit. For those short on mixer inputs you can 2 jacks to obtain a mixed stereo output of both synthesizers.

In trying to build an FM killer somebody using his or her infinite decides to include a sequencer that does the barest minimum of functions of almost any sequencer. I would have much preferred an arpegiator than the at best the poor scratch pad that is included in the unit. The ultimate kicker of the sequencer is that you need a cartridge to use it. The hard to find M-16C holds 400 notes and the even harder to find M-64C holds 1600 notes. The sequencer offers no editing what so ever. It will repeat data but it is quite hard to get a clean start/stop point in the first place. Upon playback the tempo maybe adjusted. That it all it does, the data is not even sent to the midi out port!

The midi implementation is quite good except for the system exclusive section which to put in nicely is a disaster. The following midi information maybe written as part of the patch data: 1) upper and lower midi channels, 2) upper and lower program change on/off, 3) upper and lower volume, 4)the key mode and 5) the split point if applicable. The key mode offers five options as follows:

upper - this modes sends all of the keyboard produced midi data on the channel selected for the upper synth. Lower does the same for the lower synth.

split - this modes sends data based upon the split point which is really useful for controlling two separate modules each using a separate midi channel.

Layer - this mode sends out all data on both channels selected by the upper and lower.

Off - no data transmitted.

In addition midi parameters may be set globally for patch memory change channel, sys ex on/off, u/l midi channel, u/l program change off/on and channel, u/l after touch receive, u/l local on/off, u/l bender, u/l modulation, u/l portmento, u/l hold, and u/l volume. This is really strong implementation that is quite easy to work with. What really nice is that the patch change, upper tone change, lower tone change may all be set to different channels to allow for any type of program change. As good as this implementation is the sys-ex is the complete opposite. The system can dump the contents of an active cartridge (not even its internal memory) all at once however your computer must perform a handshake with the JX at each transmission of data, so many generic librarians will not be able to work with the JX. You can’t send individual tones of patches and forget any thought of recording syx ex data because its a no go. No cassette jacks are included for saving data on tape.

The JX10 can use both M-16C and M-64C cartridges as long as you can find them. However the M-16C can only store 32 tones and no patches. These 32 tones may be utilized on a JX8p. The M64C holds 50 tones and 64 patches and a JX8P will read the first tones stored as #1-32 but not #33-50. The cartridge have an internal battery that is expected to last approximately 5 years, but based on my use the battery has lasted over ten years in one of my cartridges. The replacement battery is CRN-1/3 and is available at Radio Shack. However the battery is soldered to the memory board, so if you don’t solder, its off to the repair center and time to spend some cash.

The user interface is pretty good, it a little confusing at first especially getting used to tones and patches and going back and forth between the two to edit tones, but after a little use the interface is good and its really easy to get around. Editing tones is relatively easy using a basic data entry method similar to the JX8P. Of course the PG-800 programmer may be used and that really makes programming sounds a breeze.

The real strength of the unit is its 76 note keyboard, its ability two operate using two different midi channels and its sound. 24 oscillators are a lot to work with. I like the sound of the JX8P so of course I like the sound of the JX10. The ability to layer and split these sounds make for even more possibilities. Overall a very good DCO synth and relatively good value in the used market place.

up one level