When Roland released the JX-305 in 1998, they essentially put their wildly popular MC-505 groovebox into a keyboard format, then added 4MB of extra sound data for good measure. The result was a machine that felt equally at home in the studio or on stage, bridging the gap between a performance synth and a production workstation.
The JX-305 packs a Sample & Synthesis engine with over 600 waveforms, delivering 64 voices of polyphony across an 8-part multitimbral setup. The 61-key velocity and aftertouch-sensitive keyboard gives you expressive control, while the real-time Phrase Sequencer lets you trigger up to 16 phrases alongside the main 8-track sequencer. You get 640 factory patches, 256 user patches, and 28 drum kits to work with, plus a fully-featured arpeggiator with 43 styles. The sequencer itself is robust, offering 96ppqn resolution, 768 preset patterns, and the ability to record up to 50,000 notes. Nine real-time control knobs let you tweak the filter, envelope, tempo, and LFO on the fly without diving into menus.
Effects-wise, there are 24 processors including six reverb algorithms (rooms, stages, halls), tempo-synced delays, and multi-effects. The digital multimode filter handles lowpass, highpass, and bandpass modes with resonance control, while the LFO can be synched, retriggered, or clocked to tempo with multiple waveform shapes.
The JX-305 found its audience among electronic and dance musicians who appreciated having a complete production environment in keyboard form. It's held up well in the used market, with players valuing its dance-oriented sound library, solid sequencer, and the fact that you can genuinely perform with it rather than just triggering loops. The main trade-off compared to the MC-505 is the absence of a part mixer and D-Beam controller, but for many users that's a worthwhile sacrifice for the keyboard integration and extra sound memory.
