A 4-voice
polyphonic analog synthesizer with a 49-note
keyboard. The first synth in the Jupiter line, manufactured between
1978 and
1981.
The
JP-4 offers 1
VCO per voice, switchable between
sawtooth,
square and square with
PWM waveforms. A sub-
oscillator and a
noise generator are included, but can only be switched on/off with no level control. All 4 oscillators can be
stacked together for a
thick monophonic sound.
In the
filter section, the Jupiter-4 offers a hi-pass
VCF, as well as a
resonant low-pass one. There are two
ADSR envelope generators - one (invertable) for the VCF and other for the
VCA.
The
LFO features
sine, square and ramp up/down waveforms, with
sample/hold. It can be routed to the VCO, VCF, VCA or PWM. The
range on the LFO is quite exceptional, with what has said to be the lowest rate found on any production keyboard. The highest rates are around 100
Hz, making the LFO very flexible.
An
arpeggiator is also available, but sadly can't be
synced to an outside
source. It features up, down, up/down and
random modes. Other features include a
chorus effect, and most notably an
internal memory for 10
user programmable patches! The JP-4 was one of the very first commercial
synths with this feature.
For external control, a CV/gate
interface is included.
MIDI retrofit kits are easy to install on the machine.
On a
personal note, I must say I really
love my Jupiter-4. Sure, its
keyboard isn't that good, most of the 10
preset sounds are totally useless and the unit is quite monstrous in
size and
weight. But the
modulation possibilities are nice, allowing very nice and
exciting analog sounds to be created.
The JP-4 is often overlooked with the later
Jupiters getting much more
attention due to having more features. This is too bad, since they sound completely
different from the first one.
back to Roland