The JX-3P also features a built-in 128-step polyphonic sequencer that can be synchronized to external devices, such as drum machines, connected to its simple clock pulse input jack.

Neither "System Exclusive" nor "Continuous Controllers" (CC) are implemented, so external patch storage or real-time parameter updates are not possible through MIDI (except with third-party upgrades).

For a more immediate programming experience, Roland offered the optional PG-200 "programmer," a simple control surface with dedicated switches and potentiometers for editing each of the JX-3P's parameters.

[2] The PG-200 programmer also served to edit patches for the Roland GR-700 Guitar Synthesizer,[3] which shares the same voice architecture and sound engine as the JX-3P.

Both machines employ the same interval-timer DCO technology, use the Roland IR3109 low-pass filter, a discrete VCA, and have an on-board stereo chorus effect.