{"id":6427,"date":"2024-03-06T13:26:09","date_gmt":"2024-03-06T18:26:09","guid":{"rendered":"https:\/\/pugix.com\/synth\/?p=6427"},"modified":"2024-03-06T13:26:11","modified_gmt":"2024-03-06T18:26:11","slug":"hexinverter-jupiter-storm-diy","status":"publish","type":"post","link":"https:\/\/pugix.com\/synth\/hexinverter-jupiter-storm-diy\/","title":{"rendered":"HEXINVERTER Jupiter Storm DIY"},"content":{"rendered":"\n
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Front of finished Jupiter Storm<\/figcaption><\/figure>\n\n\n\n

A Eurorack DIY project that took some creative thinking about its packaging, this Jupiter Storm Cosmic Noise Oscillator by HEXINVERTER<\/a> came as a panel\/PCB from Modular Addict<\/a>.<\/p>\n\n\n\n

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Panel and PCB is all you get<\/figcaption><\/figure>\n\n\n\n

Whoa, the DIY PCB is wider than the panel! After meditating on how to mount the module in a case, I finally decided to commit my smaller 4ms Pod to Jupiter Storm. It fits quite well, with plenty of elbow and headroom.<\/p>\n\n\n\n

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Jupiter Storm PCB mounted on standoffs in a 4ms Pod case<\/figcaption><\/figure>\n\n\n\n

PCB assembly<\/h3>\n\n\n\n
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Completed PCB<\/figcaption><\/figure>\n\n\n\n

Besides the BOM, Modular Addict links a Mouser project cart. I copied and modified it, as I already had many of the parts on hand. The toggle switches listed in the Mouser project were different from the part given in a note in the BOM. I snagged a pair of the ones from the note, as they are specified as M5 diameter rather than M6. I did not have to drill the panel at all.<\/p>\n\n\n\n

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Bottom of finished PCB<\/figcaption><\/figure>\n\n\n\n

I traced the circuit so I could understand it better. By design the Oscillator 1<\/strong> output is affected by the feedback switch, a.k.a. the Noise Core Disruptor<\/strong>. I preferred this not<\/strong> to happen, so I made one wiring change. That’s the gray jumper wire.<\/p>\n\n\n\n

Panel Wiring<\/h3>\n\n\n\n

The build guide contains a useful pictorial of the panel wiring. It’s straightforward. Step one was to prepare all the wires and solder them to the PCB. Step two was to wire them to the panel. I used my PCB holder to keep the board in place over the pod during wiring.<\/p>\n\n\n\n

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Step one completed<\/figcaption><\/figure>\n\n\n\n
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Step two completed<\/figcaption><\/figure>\n\n\n\n
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Front panel pre-wired with grounds<\/figcaption><\/figure>\n\n\n\n

THIS DIY MODULE HAS NO WARRANTY OR SUPPORT.<\/strong><\/p>\n\n\n\n

IT WAS BUILT BY A FELINE HIGH ON CATNIP.<\/strong><\/p>\n\n\n\n

So says Hexinverter!<\/p>\n\n\n\n

Finished<\/h3>\n\n\n\n
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Module in pod with PCB peeking out from behind<\/figcaption><\/figure>\n\n\n\n
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In pod with attenuators and mixers<\/figcaption><\/figure>\n\n\n\n

Four passive attenuators for reducing CV inputs and two active mixers for mixing outputs accompany the Jupiter Storm. FM cross-modulation will be easy.<\/p>\n\n\n\n

Testing<\/h3>\n\n\n\n
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Oscillator 1 square wave<\/figcaption><\/figure>\n\n\n\n

As seen above, the oscillator square waves are crisp and swing about 12 volts P-P. All the outputs are capacitor-coupled.<\/p>\n\n\n\n

The frequency ranges go from sub-audio up to 16.7 KHz. I found that the lowest frequency of each oscillator varied quite a bit: 11 seconds, 7 seconds, and 2 seconds for oscillators 1, 2, and 3. The middle setting on the pots resulted in 560 Hz, 730 Hz, and 640 Hz, respectively. The high was 16.7 KHz for all of them. All three oscillator circuits are identical, so I can’t account for the differences, but it may be due to using non-matched transistors in the exponential converters.<\/p>\n\n\n\n

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Oscillator 2 output at the low end, 7 seconds per cycle<\/figcaption><\/figure>\n\n\n\n

Due to capacitive coupling, the outputs skew at LFO frequencies. Such frequencies are probably best put to use when combining oscillators for the main outputs. Also for FM of the other oscillators.<\/p>\n\n\n\n

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Output I with both switches off<\/figcaption><\/figure>\n\n\n\n

Just oscillators 1 & 2 XOR’ed together are available at output I. Outputs IV, VIII, and XI are subdivisions of this by 4, 8, and 11, respectively. Turning on Oscillator 3 XORs it into this output as well.<\/p>\n\n\n\n

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Output I with feedback switch on<\/figcaption><\/figure>\n\n\n\n

Sound demos<\/h3>\n\n\n\n