Released in 1993 the JD990, also known as the "Super JD" is basically a JD800 in a rack with several additional features. Some of the features that were not included in the JD800 were four additional outputs, a performance section which let you combine several programs together and an expanded amount of wave ROM to the memory from 4MB to 6MB. You could also program MIDI CC's to it's parameters. IMO it also had a fatter and warmer sound then the JD800.
The Super JD-990 is a digital ROM player synth with 24 voices and analog type parameters. These include a low pass filter, ring modulation, oscillator sync and frequency cross-modulation. The analog type parameters make it easy to program although even with it's large display this can be a challenge from the front panel. We like to use MOTU's "Unisyn" which has a great JD990 editor included in the package. There's an on-board multi-effects processor with Delay, Reverb, Phaser, Distortion, Chorus, and EQ. It has two ROM and PCM card slots on the front panel for loading in data via ROM and PCM cards from the JD800 and JV series synths. The JD-990 is also compatible with JV80 and JD800 expansion boards and can hold one internal expansion board. We also sell the JV expansion boards and usually have several used ones in stock at keyboard and accessories part of our "hardware section".
One thing I never understood about the Super JD was the AC power plug that Roland installed in the unit. It's not your standard three prong or even two prong AC that Roland has in many of it's older synths. It's a smaller custom two prong AC that I've never seen on any other synthesizer so be careful if you happen to own a JD not to lose it. You will probably have to wind up getting another one from Roland just to power up your JD again. I'm not sure if they still support the synth at this point so if you lose the cable you might wind up with a Super JD door stop!
JD990 rear panel (note the weird AC plug) and expansion slot
With it's six megabytes of ROM included, the JD is capable of producing a wide range of cool sounds. It's great for synth basses and leads and excels at creating warm synth pads. The strings and electric pianos are also very good as well as it's ability to create a wide range of synth textures and effects. We spent a lot of time with this synth and produced a large library of sounds for it that brings out it's best. Please note that Vol 7 requires the JV Pop Expansion and Vol 8 requires the JV Vintage Expansion. The other seven volumes do not require any expansions.
Our JD990 patches are available as system exclusive or standard midi files. If your computer has a midi interface or sound card connected to the USB port, you can use your midi interface to load in the sounds. We provide the software along with your order that will load in the sounds for you. Midi interfaces are an inexpensive alternative to purchasing RAM or PCM cards and we sell them starting at under $100. Sorry, but we no longer offer the sounds on the ROM, RAM or PCM carts as they were discontinued many years ago. Our sounds will also get you back in business if your JD990 battery has died and you lost all the sounds in the memory. If you need any more info please contact us via phone or e-mail.