Eurorack cases/racks. Ask questions, share experiences


#101

The 104hp 7u has 28 connectors on the current model, not sure if an earlier one had less.


#102

Flying bus cables are your friend. I’ve exceed the plug-in slots on almost every case I’ve owned, but as long as you don’t exceed the amount of power being supplied there shouldn’t be problems.


#103

flying bus cables are a one way ticket into all sorts of noise issues, I would avoid them like pest.


#104

Never had a problem FWIW


#105

For me it’s not much about noise but rather usability. Flying bus cables are a real pain when you’re plugging/moving modules compared to busboards…


#106

It’s one of those things where you don’t get automatically a lot of problems. You can use them for years without an issue, especially if you don’t do multi-track recording, are not using high-gain circuits or OTA-based stuff and only have well designed modules in your system. But since these things are often hard to avoid, (I mean, why would you live without wavefolders, distortion, or OTA-based VCAs?) the rule of thumb is to avoid anything that could potentially cause problems down the line.


#107

Does anyone know if you can add power to the Intellijel 7U cases? I think it has 28 connections, but if I add in a bunch of 2hp units, it would have like 32… Is there a solution?

Thanks!


#108

maybe @kisielk can answer your question.


#109

FYI here’s what I’m looking at for my case setup: https://www.modulargrid.net/e/racks/view/621184


#110

edited

just to clarify, if you are talking about just adding more connections only (and not additional power) you could jump the dc from the main board to a second board. details on the install guide for the TPS80W board

https://intellijel.com/product/triple-power-supply-80w-3u-6u-busboard/


#111

I added a 4ms bus stick board to my 7U 84HP case that is just connected to one of the connectors on the TPS80W busboard, everything works fine. The only difference I’m aware of is that the modules powered through the 4ms board do not benefit from star grounding. Just in case, I tend to give digital modules their own connector on the main board and use the 4ms one for other things. I’m not sure there’s an actual difference for me though :slight_smile:.

There’s more than enough power for my case with the TPS80W so a passive busboard is an inexpensive and efficient solution…


#112

By definition this is violating the star ground principle as your additional board would add a second star centre (if it, too, is a star) or be nothing more than a rigid flying bus if not.


#113

That’s one approach to life. I’d rather worry about actual problems, of which there is no shortage. :slight_smile:

Seven years and tons of crap modules running off a couple different dreaded switchmode power supplies have resulted in NO noise issues with ribbon cable distribution (aka “flying bus boards”) here. I have three label-released albums made 100% on the modular (under “prettyhowtown”), and a well-known mastering engineer said my files sound as good, technically, as what he typically gets from pro studios.

Thousands of others have had the same experience. I now run Intellijel TPS30W supplies (a “powered bus board” design), but that’s because I was exceeding the current capacity of my previous supplies, not because of noise issues. Ribbon cable distribution is really helpful for those of us who want/need very compact cases or have smaller systems. The same applies to switchmode power supplies. No one should be afraid to use either of them.


#114

mm, yeah i guess i misspoke there. main point was you can jump the dc from one board to a second, vs using a flying cable on one header to add additional connections. edited my post to reflect.


#115

Correct, although the electrical principle in both cases is identical, so there’s no gain to using a hard jumper board versus a flying lead other than a negligible amount of shielding (even if the board features a full-layer ground plane, that won’t cover the jumper or the individual leads to the modules, so you gain very little).

In short, if your backplane isn’t sufficient, any additional expansion is not inherently electrically better than a flying lead. Just keep the runs as short as possible and keep the largest power draws towards the backplane and you’ll likely be fine. As @jnoble said, solve problems when you have them, don’t worry too much about these other issues - these electrical distribution systems have worked just fine for decades, and the only advantage to other solutions is if you have a specific kind of problem, and then it’s a case-by-case basis (see what I did there) to solve it anyway.


#116

not really sure about the fix problems when you have them. I mean, in general I agree about not worrying too much about all the things that could potentially happen, but my experience is that it’s really annoying if a deal-breaker problem shows up when you do not have time to find a solution for it. My first problem with weird (unintended) noises coming from the modular was in the middle of a performance project. For some reason my system worked totally fine in the studio but started spitting out all sorts of crap when we started to do the things live. I didn’t have the time to figure things out so I just kept the noise.

@jnoble it should be said that indeed most of the time the noise floor is so low that you will neither hear nor otherwise have any issues with it down the line especially if the music you make is relatively loud, as when you make EDM, techno or in general music that has a relatively constant level, and lots going on. I guess you can get away even with crappy modules and flying busboards in many cases. Maybe your modules weren’t that crap? It’s usually very hard to know which modules are actually well designed and which not. Some modules from brands that look very respectable turn out to be really sloppily designed if you start to look closer, and some stuff that looks like crap (and maybe is even cheap) can be totally solid.
I did use a Meanwell PSU wired directly to a standard busboard for a long time and in some configurations it did work like a charm, despite its specs being less than idea on paper. It should also be said that flying busboards are just a little bit worse than normal 1ounce serial-type busboards (the standard Doepfer style busboard where all connectors are in series – not arranged in a star config – and which has a relatively thin copper layer for the ground bus). Still, I would personally not use flying busboards anyway.

But getting back to the topic and to what @davidcool wanted to know: what could work – but I’m not sure that it would not create any other issues – is making “mini flying bus cables”, i.e. instead of using the standard cable with 1 connector on each side, you could make yourself some cables with an extra one in the middle and connect two modules on each connector on the busboard. In theory that would still be better than attaching one big flying bus cable, and probably handling of the cables would also be easier. You can buy the cable, IDC connectors and the pliers to put things together


#117

That’s easy: if a module doesn’t behave itself in a system where everything else does work right, then you have your culprit. :smiley:

But one of my first electronics projects was a LM317-based variable power supply for electronic music circuits back in the early 80s (before going to college as an EE major and a later career in audio electronics), so I have a little background on this.

I perform live with my modular–a lot–and have used everything from measured 94VAC “agricultural” power (whose wiring had to be seen to be believed) to random gas & diesel generators to an ugly modified sine inverter fed from a lithium battery and have never had a problem of any kind related to power. If an OTA-based design started giving me problems after all that, I’d blame the designer and sell the module. Naive designs like the 2164-based VCA used in the busboard tests you silently reference here are likewise not something I’d want to deal with.


#118

FWIW we usually tell people that using flying bus cables in the Intellijel cases is ok, with the caveat that you won’t get the same star grounding scheme as the rest of the power supply. Whether or not that has any actual effect on your particular setup really depends on what else you have there.


#119

I got a response from Scott @ Intellijel:

It is possible to power more modules using a flying bus cable. This connection can be a bit more noisy, so if you do this we recommend putting your non audio modules on the flying bus cable.

So what are examples of “non audio”? Like ADSRs or attenuverters?


#120

does anyone know which 1U size format the elite 7U cases that make noise uses are compatible with? as in, the 1U row that they use for their cv bus module - if you wanted to swap it out would you go with pulplogic style tiles or intellijel?