Offworld-2: USB power utility

This might be useful when your case is critical with power but I don’t see why it would be a must. Personally I thought powering the interface directly from the module was a step forward regarding usability. Or are there any issues with that which I overlooked by now?

A nifty solution for flexibel switching between modules would be nice of course but I do not see anything that could manage the various numbers of possible combinations with trilogy and multiple Ansibles.

Personally I would like a triple switch with bidirectional paths (switching grid to different modules or switching between Grid and Arc for one module). Or two of them to crosspatch different configurations. Or wait, a USB-matrix switch with preset storage…:smile_cat:

Switch does not work with the Arc. I don’t know why though.


> This might be useful when your case is critical with power but I don’t see why it would be a must. Personally I thought powering the interface directly from the module was a step forward regarding usability. Or are there any issues with that which I overlooked by now?

Ive only just got my stuff so ive been an avid reader of liiines for a while and absolutely no personal offense please, but i do notice you seem to have a lot of strange power related problems over time (i might be wrong about that but casual observation makes me think that)
I think what you might not be separating here is the power of the modules and the I2c usb stuff. Having your case loaded or not isnt going to make any difference to that bus - hence this device and the pullup fixes…seems this device is a critical point of failure (and that also means performace issues that screw up call backs et al…
I guess the device I was talking about refers to A and this aims to solve B - if that makes sense

the issue here is noise some people are experiencing with some power solutions.
the trick is to use usb power, which doesn’t have ground (removing ground from a 3 prong power plug is a popular fix for eurorack noise issues, but that seems dangerous).

pretty sure arc works with switch. at least there is no reason why not.

I yet have to encounter noise issues with my psu3, so yes, only people with noise floor issues need this.

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it’s not a must. it’s only helpful if you’re having power shortages or experiencing noise related to power draw

it’s not a smoother or anything sophisticated. it’s simply offloading the power draw of the USB devices to the external power supply.
need this bad boy :slight_smile: crazy specs (usb-c)

Ah, I understand - Thanks for the explanation!

I am afraid I don’t understand what you are saying here but I am not under the impression that I am having any power issues.

super sorry to be ignorant on this one… the noise in my rack has gotten rather unbarable with the ansible / grid connected, so i’m back to become smarter:

  1. am i right in the assumption that the offworld-board is not in eurorack-format (– will therefore not be mountable)?

  2. is there another way to get rid of the noise? i’d be happy to unfold my laymans soldering skills and lay a careful hand on the grid or the module.

  3. would this work as an alternative to the offworld-board?

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not 100% sure, but i don’t believe those y-cables maintain fully isolated power and data paths, so you would still get interference. i think the second usb connector (that you would hook to a power supply) merges with the connection to the data connector. i could, and would love to, be wrong as this would make for a very convenient solution!

correct, but perhaps someone will take up the cause. personally i think i’d prefer it live outside the case - rack real estate is precious!

aside from the diy barrier, i think this is the simplest solution at the moment. the only alternative i can think of is finding a used switch module.

I’d like to take a stab at making a mountable version. I’d prefer vertical connectors, but I can’t find USB-A and mini-B connectors that are roughly the same height. The USB-A connector used in Ansible looks like it would work well, though. Is it an off-the-shelf component, and if so, would you mind sharing the part number for it?

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but not sure how to solve the problem of the mini?

Thanks! So, that connector has a height of 10.5 mm (above the PCB surface), and here’s a mini-B that’s 9 mm:

But that’s probably too big a difference. Dang.

has anyone built one of these?

my setup still doesn’t really require offloading the power draw, but i tested this again today and it works well.

considering making some plexi panels to make it less of a raw circuit flopping in the cable nest

@billyhologram so i’m back on investigating a 2hp panel-mount version of this. it’s harder than it should be! but mainly because of the mounting.

i can get the mini and A USB ports more nicely thin by using this part, which is mid-mount:

and then using the same mini’s as above. but then i hit a wall at proper right-angle mounts.

so, perhaps i’ll just draw up a new version with this “slimmer” USB A port, create a panel enclosure, and call it done

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Hrm, maybe something like these right-angle standoffs could work. Not sure where the mounting screws would end up relative to the USB ports, though. Might not look so great if they were off-center? (That’s something I don’t like about right-angle components.)

I’ve been meaning to build one of these (the power supply in my Make Noise skiff definitely doesn’t like the grid very much), and maybe make a little enclosure for it as well, but haven’t had any time lately.

I’ve just ordered 3 boards to the UK. Will order parts shortly. Is anyone in UK/EU interested in one of these - if so, I can order all the parts (2xUSB A, 3xUSB mini-B) and we can save a bit on postage costs. Total should be about £12 for board and components. Get in touch if interested!

With @scanner_darkly’s Teletype + Grid beta (Grid ops / integration), it seems like this is now something worth building. Has anyone made a 3D-printable case?

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i have a batch of these on order:

which includes a plexi top/bottom sandwich. they should be robust.

but a 3d printed thing for the DIY circuit would be great!

Order from OSH Park


I was thinking about this last night after reading through the monome ecosystem thread.

I’m wondering if it’d be possible to make a, say, 3 in -> 3 out (or whatever I/O count makes sense) USB power/switch that is addressable by i2c.

My thoughts are that It’d be very cool if you could trigger a change of grid connection from say, a Teletype to an Ansible with a trigger to Teletype. I think this could possibly be an interesting way of controlling your ecosystem in a very Monome way.

The cool thing about the Monome interface controllers are that they are completely “static”, in the sense that there’s not mechanical on/off switches (grid buttons don’t “depress”), or potentiometers that have mechanically-defined position (arc has endless encoders). Which lends itself to seamless switch between different “apps” running on different modules requiring the various interfaces (none of the “you have to move the knob to where it was to make it start changing things” UX weirdness)

In practice, I’m thinking it’d be cool if you could control LFOs with cycles, then cause a trigger to switch the arc to controlling some other thing (maybe some future arc + teletype turtle app :)?), then trigger again to switch back to cycles once you’ve done whatever you need to do with the other app.


I have 2 spare Offworld-2 boards (as per the first post of this thread) in the UK. If anyone in UK/EU wants one I can post it if they send me a few quid on paypal.

Put together one of these and works like a charm despite my dodgy soldering.