Roland JD-800 - Technology

Technology

The JD-800 combines sample playback with digital synthesis, a process that Roland calls Linear Arithmetic synthesis, a technique Roland had been using to great effect in the Roland D-50. The JD-800 has 108 waveforms built-in, but these can be expanded via PCM-cards. There are waveforms in a variety of categories, like; analog synth, acoustic instruments, like guitars, woodwind, brass and voices. Most of these waveforms are very short and are designed to give character to the attack portion of a sound, while some longer ones are designed for creating pads, or the sustained part of a patch. The JD-800 was the first instrument from Roland to have its core sound set of waveforms developed entirely in the United States, under a short-lived branch of Roland's R&D-LA office in Culver City, California. The core sampled waveforms and Factory presets of the JD-800 were created by Eric Persing.

A patch, or single sound, in the JD-800 consists of up to 4 tones. As every tone consists of an almost completely independent synthesizer voice a patch could be considered a layer of up to 4 different synthesizers. In single mode the JD-800 plays one patch at a time, but in multi mode it is possible to play 5 different patches, over MIDI, plus an extra "special" patch. The special patch has different waveforms assigned to the 61 different key on the keyboard, so is used for drums and percussion sounds. The JD-800 has one effects section. In single mode 7 effects can be used simultaneously, in series, so all tones in a patch go through the same effects. In multi mode 3 effects can be used at the same time, all patches sharing the same effects, though a patch can be routed to bypass the effects.