Home Music Synth Stuff Store Contact

Jupiter-4 Resources and Manuals

An archive of various Jupiter-4 manuals, including all of manuals and resources for the various MIDI retrofit kits that have been created for the Jupiter-4 over the years. And also some notes regarding servicing various parts, and other sundry ramblings.

Service Manuals

Owner's Manuals

Jupiter-4 Slider Replacements

Roland used ALPS sliders, it's possible to replace them with Jeffrey Lee's riser adapters and modern sliders (Bourns PTA3043-2010CIB503) that can accomodate the values, to make it easier I just have this portion split out in its own article:

Jupiter-4 MIDI Retrofit Solutions

The Jupiter-4 has been plagued with subpar MIDI control options for the longest time. Originally László Kõvári's Io kit was the only option to actually allow filter automation and a few other things (everything else was, more or less, just basic MIDI note control). Unfortunately the Io MIDI kits seem to suffer from degradation problems and it's on longer manufactured due to retired parts, I'm not entirely certain if this is due to the firmware developing internal 'software' bugs over time or if it's bitrot from the ATMEL ICs, but one thing is for certain that they are developing issues as time progresses.

Now in 2022 the Hamburg-Wave has been released that replaces *both* the 'CPU' and 'Assigner' 8048s. No soldering is required and this also means that any Jupiter-4s who had failed assigner board ICs (P09011-036 D8048C 011) can be rescuitated. There are a few missing features from the Io Kit such as white noise volume control and the mysterious second LFO that I don't think ever really worked properly; but I don't actually think these should have been changed to begin with. The white noise is pretty quiet as it is at max volume and adding a second LFO may change the Jupiter-4's character too much.

If anyone is looking to add MIDI capabilities to the Jupiter-4, I'd recommend the Hamburg-Wave and nothing else really. It's also the cleanest kit that doesn't require any sloppy wires or additional PCBs.


Resources for the Hamburg-Wave Jupiter-4 MIDI kit. Manufacturer's website is located here: https://www.hamburg-wave.de/

Covariance Io MIDI Kit

Resources for the Covariance Jupiter-4 MIDI kit. Manufacturer's website is located here: http://midipolis.blogspot.com/p/manuals.html

CHD Elektroservis JP4-KBD

Resources for the CHD Elektroservis Jupiter-4 MIDI kit. Manufacturer's website is located here: https://www.chd-el.cz/products/roland-sh09-midi-interface/

Jupiter-4 Card Voice Revisions

I created a vectorized version that's easier to read for all of the different card revisions from the service manual (just because it would be nice and the legends were done a bit poorly).

JP-4 Card Revisions

Other Resources

I have a few other pages sort of relating to the Jupiter-4, regarding the filter and UA726HC, they are referenced here:

spotify bandcamp soundcloud twitter itunes