Roland's two new polyphonic keyboards have found their way on to my test bench this month and have proved to be something of an eye-opener. With the exception of the System 700 and its computer companion the MC-8 (and also perhaps the SH-2000), I have never been at all excited by Roland keyboards. I've considered them to be fairly good, reasonably priced instruments, but nothing special. (I do hope thousands of irate Roland owners aren't about to arrive on my doorstep to show their disagreement.)

However, these two new products are going to give quite a few other manufacturers something to worry about. I am beginning to think that the popularity of the monophonic synthesiser is starting to decline — of course there will always be a demand for the Minimoog and one or two of the cheaper synths — but fewer and fewer new monophonic products are getting a grip on the market. Roland have realised this and have produced these two instruments at a quite amazingly low price. (See page 60.)

Jupiter 4

The Jupiter 4 (or JP-4) is defined as a 4-note programmable polyphonic synthesiser and, in my opinion, seems to have been modelled — to some extent — on the Sequential Circuits Prophet 5 (see SI July '78). The fundamental differences are that the Jupiter 4 has only one oscillator per voice, and has a smaller programmer. To those who find the last sentence confusing, hang on in there — all will be revealed (ugh!).

The Roland JP-4 has four separate 'synthesisers' (or voices) built into it, but each of these is controlled by the same slider or switch on the front panel. This means that each voice will have the same sound — known as a homogenous system — enabling up to four notes to be played simultaneously, one 'synthesiser' for each note. Each 'synthesiser'/voice in the JP-4 consists of: (a) One voltage controlled oscillator with square, ramp, and pulse (width variable) wave-forms. The range control pitches the oscillator at 16ft, 8ft (fundamental), and 4ft. There is also a sub-oscillator that can be switched on to beef up the sound, producing a square wave one octave down; (b) One noise source; (c) A low frequency oscillator — sine, square, ramp up and ramp down waveforms; (d) A voltage controlled filter (high pass and low pass), with a 24dB/octave characteristic and an ADSR (attack, decay, sustain, release) envelope generator to sweep the filter up or down; (e) A voltage controlled amplifier with an ADSR envelope and level control.

The JP-4 is such that all the variables associated with these sections of each voice can be recorded and programmed into a memory, details of which I will explain later. The instrument has a 49-note C-C keyboard above which are the controls for the voices. The voices can be further modified by a set of controls situated to the left of the programmable section. These controls include a Delay/Bend section with which the modulation of the low frequency oscillator can be delayed and the programmed speed altered. There is also a trigger section where the voltage controlled filter can be modulated by a sample and hold source creating random variations in the filter cut-off frequency. To the left of the keyboard is the bend/modulation lever. This is a sprung lever that can be moved to the left or right to control various parameters. Three switches enable the voltage controlled oscillator, the voltage controlled filter or the voltage controlled amplifier, to be bent or modulated by the lever (a rotary sensitivity control determines by how much). This is a very versatile system, but I found the actual lever had a very cheap feel about it. Also housed on this panel are the portamento controls, rate and on/off switch, and a transpose switch to shift the range of the keyboard down an octave.

Now we move on to the interesting bits, which unfortunately are situated along the front panel underneath the keyboard. This is fine if the instrument is played when stacked up on another keyboard but, as this is a polyphonic machine, I doubt whether this would often be the case. Anyway, moving along this panel from the left the first control is a tuning knob; next to this is an ensemble switch. The ensemble gives a rich chorus/reverb feel to the sound and it also converts the mono output from the mixed-down voices to a stereo output, which sounds especially good when playing through headphones. Next comes the arpeggio section — yes, an arpeggio section. This sort of thing is normally found only on home organs, but Roland have been able to incorporate this into the JP-4 with ease and to quite astonishing effect. There are four patterns of arpeggio available: up, down, up and down, and random. It is performed on every scale within the 4-octave range for each note pressed, in the order pressed, and in one of the four patterns. It is rather confusing to try to explain this in detail, but when a full chord is played it really does sound impressive. The speed at which the arpeggio runs is determined either by the rate control in the trigger section or from an external source.

The four switches to the right of the arpeggio section determine key assignments. Unison 1 puts all four voices into monophonic mode; if you press two notes the lower one sounds. With Unison 2, if one key is pressed then four voices sound, if two keys are pressed the voices are paired off, and if three or four notes are held each voice will sound individually. Poly 1 cycles around the voices, eg if one note is pressed continuously voice A will sound, then B, C, D and back to A etc. (This is similar to the continuous mode of the Oberheim 4-voice — see SI May '78.) Poly 2 always plays voice A first and only moves on to voice B if voice A is held.

Unfortunately, if more than four notes are played on the JP-4 the last note played will not sound — this can be a bit awkward sometimes. Most other polyphonic synthesisers use a 'robbing' system, whereby the fifth note played will take over from the first note. However, this is not a disastrous failing.

Alongside the Key Assignor is a hold button which will hold any note played either until replayed by another or until the switch is released. This is especially useful when playing with a multikeyboard set-up.

The only section I haven't yet covered is the programmer. This again is situated along the front panel and consists of: eight compu-memory switches, into which eight patches of your own can be stored; ten preset sounds including bass, strings, funky clav, piano, voice, trombone, sax, trumpet, synth and 'the Force'(!); a manual switch, which disconnects the programmer; and a 'write' and 'protection' switch. To programme a sound into the 'compu-memory', the manual button is pressed and the required sound set up on the programmable section. The required memory location switch (1-8) is then selected and both the 'protection' and 'write' buttons are pressed; the sound is now programmed into the memory. The Jupiter 4 has a battery back-up which stores the programmes in the memory even when the power is turned off. Unlike other systems this battery is recharged when the power is on so, as long as the instrument is switched on at least every six months, the programmes will remain intact indefinitely.

The preset section of the memory leaves a bit to be desired; the bass, funky clav, trombone and trumpet presets are quite good, but the voice and 'the Force' sounds are best forgotten about. None of the presets have any sustain programmed into them; however, the sounds one can achieve and programme into the 'compu-memory' can be very pleasing. I tried a great organ sound with click attack, a much better string sound, a bell timbre and several good sounds set out in the owners' manual with satisfying results.

The major drawbacks to the JP-4 are: (a) There is only one oscillator, with no triangle wave for each voice. This is obviously sacrificed to keep down the cost and therefore not too much should be made of it, but a 2-oscillator voicing system would make such a difference to the sound; (b) The filter has that typical Roland 'mushiness' to it that I don't like, but this doesn't prevent you from getting good sounds; (c) Again, the awful Roland keyboard that feels as if it has come out of the 1920s. These are really rather minor complaints considering what you are getting for your money. Polyphony for all!

Paraphonic 505

Now on to the somewhat more simple Paraphonic 505, which basically consists of three sections: a String section, a Synthesiser section and a Bass section. Each section can be played by itself or simultaneously with the others. The keyboard is the same as that used in the JP-4, a 49-note 4-octave C-C, the only difference being that the keyboard is split at the middle C to give a 2-octave lower and 2-octave upper section. The Synthesiser and String sections will work over the entire keyboard but the Bass will only work on the lower half.

All the voicing controls are set on a panel above the keyboard, the tuning controls on a panel to the left. Let's start by looking at the String section. Two tablets (particularly nice rocker switches) introduce strings to the upper and lower halves of the keyboard. For each part there is a slider with a centre stop; pushing the slider fully up gives a 4ft string; pushing down an 8ft string. Therefore the two can be balanced. The attack of the strings is also variable (more than most string machines) and their release time is governed by a control shared with the Synthesiser section.

The Synthesiser section will play polyphonically but has only one filter and voltage controlled amplifier. Various footages of waveforms can be directed from the upper and/or lower sections of the keyboard, into the voltage controlled filter which can be modulated by an ADSR envelope generator and/or a low frequency oscillator and thence through a voltage controlled amplifier whose level is controlled by the same ADSR envelope. A second touchswitch allows the ADSR to be triggered either when a key is newly pressed or when a key is pressed while another is still being held. Ensemble (a chorus effect) can be introduced if necessary.

The Bass section offers three tonal variations: contra bass 16ft, tuba 16ft and cello 8ft, and can only be played monophonically with a low note priority. An AR (attack-release) envelope is used to shape the amplification of the bass — with ensemble if required.

Balancing between sections is achieved by two sliders: a balance slider between the Synthesiser and String sections, and a level slider for the Bass section. A 3-position Ensemble mode switch gives, in position 1, a fairly subtle chorus effect, in position II a fuller richer quality to the sound, and in position III a rather unreal, over-the-top, chorus modulation effect. Vibrato is generated by means of a low frequency oscillator, with depth, delay and rate controls.

The tuning panel (to the left of the keyboard) has, in addition to a straight tuning control and master volume control, a bizarre pitch shift system. This can be operated either manually or automatically so that, when a key is pressed, the pitch of the keyboard starts at a preset lower frequency and slews into the normal pitch at a variable rate. Manually the pitch can be shifted by a slider or by a pedal. The pitch shift works on all three sections and, in my opinion, is a waste of time.

Overall, however, the Paraphonic 505 is a good looking, well-made instrument. The string sound is good and, with intelligent use of vibrato and delay, gives most agreeable results. The Synthesiser section is adequate though nothing special, whereas the Bass section with ensemble can produce an extremely powerful, rich sound.

Both the JP-4 and the Paraphonic 505 are housed in very sturdy metal cases with attractive wooden end-checks, and the two instruments are roughly the same size. Neither instrument comes with legs, lid or case, but then at the prices they sell for you can't have everything. They do come with very detailed owners' manuals, explaining every facet of the instrument. These manuals have obviously been translated into English in Japan, resulting in one or two amusing phrases such as, 'the more the slider is slided up... ' and, 'Upper the slider is set, the longer the delay tone becomes'. Mostly, though, it is very easy to follow.

Roland seem to be pacesetters as opposed to just following the rest; these two instruments, especially the JP-4, offer us keyboard players sounds we want at a price we can afford.

The DC Star System

Starting this month I have decided to draw up a chart comparing the reviewed instruments to their nearest competitors, highlighting various aspects. These include:

Overall sound: A general heading concerned with the quality, depth, richness, and natural feel of the sound. Obviously this is the most subjective heading, but it should be of some use for comparison purposes.

Versatility: A guide to how many different and useful sounds can be produced by the instrument.

Construction:
(a) Appearance — obvious.
(b) Roadworthiness — will the instrument hold together on a 3-month tour, or a journey on top of a London 'bus?
(c) Reliability - this can only be determined after a while and for some new instruments won't be quoted.
(d) Ergonomics — how easy it is to use.

Value for Money: Is it worth six years' wages?

I've decided to adopt a star system with a maximum of five stars. The chart will represent not only my opinion of the instrument, but will be influenced by others who have tried, or who regularly use, the instrument and with whom I have spoken.

Dave Crombie is resident electronic design engineer at Rod Argent's professional keyboard store in central London.