A work co-designed with Ciiyte (Cai Yitong). Cover image photographed by Deng Xiangyu.
Overview
6U104HP is an aluminium Eurorack power case, 6/7U high and 104HP wide: it powers a modular system and provides the I/O and mounting hardware around it. This case is the basis of most of my modular work.
We designed one multifunction strip above the module rows and one below: ten 1/8'' and 1/4'' TRS jacks with built-in converters (currently passive, convertible to active); five 2-6 mults (convertible to active mults, mixers, S&H, logic and so on); two XLR sockets for gooseneck lamps (convertible to USB and other uses); and a cascadable power output.
The supply is our own design: high-power, low-ripple, with a 12–36V wide input; the body and lid are aluminium; the carbon-fibre side panels take single- or dual-case stands. The single- and dual-case stands are carbon fibre too, so they weigh almost nothing.
The 75×75 VESA holes on the back mean the case does not have to sit on a desk: with a portable-monitor stand or a robot arm it is equally at home playing out or working in the studio. I like to mount a robot arm on the side of the "Babel" (four cases stacked), so that five cases, 3120HP of modules, can be used together.
From customer to co-developer: three versions
When I first got into Eurorack I wanted a case that was affordable and good to use, but the ones on the market were either very expensive or not very good. So I asked Ciiyte (Cai Yitong) to design one for me.
The first version was made of extremely thick anodised aluminium. Several problems only appeared once it arrived: the natural finish of JLCPCB's anodised aluminium looked terrible; it was heavy — a single empty 7U104HP case weighed 3.5kg; the stand would not fit at all, because of a design error; and there was no lid yet. I received the case at school, shipped directly from JLCPCB together with crude, custom-length CPCI-style rails, and assembled it myself with a senior schoolmate, turning the screws by hand. Everything about it was crude and wild.
For the second version we abandoned anodising for powder coating and added a lid, which improved the feel considerably. But the stand was still an insert type — long stand tabs slotted directly into the case's side panels; the empty case still weighed 3.5kg, the rails were still very heavy, and the side panels were 7-series aluminium. At that time my case was a 7U104 with the I/O on the 1U row, including MIDI I/O. Later I found that I did not need MIDI I/O at all.
Around this time Xuanning designed Asian Rail, a very light aluminium weight-saving rail. The third version adopted it, and finally made use of the upper and lower strips instead of taking space from the module rows. The stand also changed from an insert type to a quick-release design fixed to the sides with brackets.
We took the weight off one gram at a time — at that point we were weighing even the internal circuit boards and the connectors. I myself gave up 7U to save weight; another reason was that I bought six cases, and choosing 7U104 would have given me six 104HP 1U rows, which there was no realistic way I would fill.
The weight reduction ends here: the first version's empty case weighed 3.5kg; the third version weighs 3.5kg fully loaded, with the lid on, in most configurations.
Thanks to Ciiyte (Cai Yitong) and FunnyCoco (Deng Jianbo) — none of this would exist without them.
My contribution
Design and testing of the stand mounting system
Design of the VESA holes: I researched the dimension and screw standards, and carried out the VESA testing for the third version
Design of the I/O and multifunction areas in the upper and lower strips (optional mults, rectifiers, logic, S&H and so on)
Design of the gooseneck lamp sockets
Design of the power chaining between cases
Design of the protective lid
Design of the weight-reduction measures
Selection and testing of the handle (my responsibility)
The gooseneck lamp sockets were my proposal. In 2023 Dawless Teahouse held an event at System; I performed with Tredd, YK3328 and Tang Zhengyi as ShangTide on the Danlu stage. That night every light was switched off and it was pitch black, and we could hardly ask the venue to light our gear — modular synths are too complex for that; without light we had no idea what our hands were doing. The same thing happened several more times, so we decided to design these lamps into the case. The lamps originally used BNC connectors, but they swivelled around during performances — unbearable — so we switched to XLR.
Where it has been shown
The case was exhibited twice in 2024 and twice in 2025, and I was at the booth as one of the developers each time. The second version was shown in 2024 and the third in 2025.
Music China 2024 is, you could say, where I became a modular developer. A friend came and jammed with me, and I tried patching every oscillator at the show into one sound: more than seventy oscillators were sounding at once that day, and I still like doing that. Someone asked me how this differs from software, and I did not know how to answer. Tamix was there too, and invited us to Modular Commune 2024.
At Modular Commune 2024 I talked to people all over the hall, and traded a clone of Mutable Elements we had built, plus an Error Instruments Paul, for a Tele Blender special edition whose panel says "do not lick" in Chinese; it is still one of my favourite modules. I also came away with a pile of free T-shirts. We lent our prototype cases out across the floor: the power supply in one friend's case was playing up, and another had more modules than cases. I also used an octopus passive mult to make a patch-cable flower arrangement.
For the two 2025 shows we brought a four-case "Babel": the 2024 version could combine only two cases, while the 2025 version combines into a single 24U104HP case. Developers from Behringer came to the booth and talked with us for a long time, and I improvised a piece for them; at the modular festival I had a very good conversation with the developers of Holocene. I traded a large pile of modules with Befaco and Instruō, and sold a Grids clone I had not used for a long time.
Music China 2024.10.10–13, Shanghai New International Expo Centre (second version)
Modular Commune 2024.11.08–10 (second version)
Music China 2025.10.22–25, Shanghai New International Expo Centre (third version)
Modular Commune / Beijing Modular Festival 2025.11.14–16 (third version)
The case is now on sale as a product, with about ten sold so far. Selling a product like this in China has a certain difficulty: it is too niche, too specialised and too large. Many people from abroad have asked whether it can be sold overseas, and that has not worked out yet, held up by cost, paperwork and the difficulty of after-sales service at a distance.
For orders, please contact:
Email: [email protected]
WeChat: Ciiyte