Ansible & grid / power issues?

just got an ansible from @cillianjohn and i’m (almost) very happy, yet i’m experiencing a weird buzzing from my (main) VCA which increases when more LEDs are bright on the grid.

obviously some power issue, but judging by my specs via modulargrid, i should have enough headroom on all rails. running my rack off a 4ms row power 40

any hints as for what i should do? anyone have similar experience?

i’ve experienced this when using ansible (+grid or arc) with my pulplogic lbz54 case… more leds = louder buzz. it becomes a lot more noticeable when i route audio thru the built in spring reverb circuit.

i have a larger case with the intellijel tps80w and i can hear it there, too.

Having the same issue with Synthrotek Super Power supply. For now, solving that by powering ansible by spare uZeus, without anything other attached to it (if e.g. power ansible and mixer or vca from uZeus – there will be buzz when grid is connected).

Maybe power regulator converting +12V to +5V to power grid generates this noise and feeding it back to power rail? I don’t know.

Going to try noise filtering busboard soon, and hope that capacitors on power lines will filter this.

I think ideal solution would be to get monome switch, wish they were still available.

mh… damn /: this is really annoying. almost worst, that the buzzing isn’t constant – can’t really “play” with it i’m noticing, cause when switching to menus and back etc, the output/sound of the modular changes noticably.

i’ve ordered a new (high!-)powersupply – hoping this will solve the issue. but if it’s really due to conversion, then … mh …

yeah i thought it was a power supply issue, but i’ve heard it on 3 different models now. pulplogic 1000w, uzeus & intellijel tps80w. i thought the intellijel supply would fix it, as many have said it’s super quiet with that star grounding layout.

i have switch and it does remove the noise, but i use that with earthsea and meadowphysics for the grid & ansible is usually connected to the arc.

Would one of these be a cure?

Received an Ansible today but have no power to try it yet. My Synthrotek deluxe power crapped out after two hours. Thinking of getting the Trogotronic power supply now.

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that trogo silencer looks promising. thanks for pointing it out.

Is it a high frequency noise?

I fixed this with with a second hand Switch but that silencer looks really interesting.

Another tip I got from Brian was to change the capacitors if the 2015 grid has the old ones which should reduce the noise (though probably not completely) 2015 grid noise fix

Also someone on this forum may have an old Ext 5v they could sell you which may also do the trick.

just ordered the m05 silencer… thanks for this tip! – i’ll keep you guys posted when i receive it.

thanks @jasper_ryder, too! i wasn’t aware of this… will check my monome to see if it’s a faulty one.

Provides 5 Volts

Just a word of warning, without knowing the details: I’d be cautious with that if you already have 5v in your rack.
I damaged my monome trilogy modules by inserting a mutable volts regulator into a case that already had 5v… (hidden documentation of the cell series, yay). Hopefully I’m overreacting here…

Edit: Ansible doesn’t draw from 5v, so it should be safe. But others in the rack might (?)

Also: ext5v should be open sourced somewhere IIRC


well, judging by my bad eyes, my capacitors do look like the non-noisy ones… narrowing down the problem – can anyone confirm this?

for reference, here’s a recording of the noise (first with no grid plugged in, then with idle grid and finally jumping through submenus / more LEDs):

these are the correct caps.

keep in mind the ansible draws all power from the 12v line, re trogtronic.

i’m sorry that there is so much trouble when it comes to matching a power supply with these modules.

one solution to check is to ground-lift the ACDC power brick for your power supply-- often the noise is ground related if you’re connecting to a grounded mixer or set of speakers.

another solution is to offload the USB power using either a Switch, ext5v-- both of which we’re out of-- i’m sorting out a new/better solution. one of which is this thing:

(edit: removed link prior to testing)

basically it provides external power to two devices. external power comes from a usb power source as well, so no voltage issues-- and you can use an iphone-style charger which are ubiquitous. this thing isn’t mountable, it’s just a dongle. we can design some mountable versions or different configurations quite easily. also this one doesn’t switch. it’s just power isolation for two devices, ie grid+arc

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hei brian, thanks a ton for jumping in! … i’d like to give this ^^ a shot – can you tell me how to do so (or where to find out)? eurorack and power are quite new to me… i recall having read that it’s not ideal to have an ungrounded power supply (such as the 4ms row powers).

would something like this work, or am i on a totally wrong page?

a few troubleshooting results using arc + ansible + intellijel tps80w

  • ground lift on the intellijel/meanwell power brick did not remove the noise

  • ext5v added between arc + ansible (no ground lifts at all) did not remove the noise

  • ground lift added to ext5v power brick, noise gone!

so it seems that externally powering the grid / arc and removing it from the shared ground path is the solution. i’ve heard that ground lifting is hazardous, but i’m assuming that because i’m only lifting the arc (as opposed to my higher voltage, semi-exposed eurorack bus) and it’s circuitry is well hidden i’m probably not exposing myself to much risk.

for those wondering, my ground lift looks like this:

one more data point:
the intellijel tps80w has tons of 5v. i’ve tried running trilogy modules directly to the grid without switch or ext5v. the noise is there, too.

@tehn is that oshpark board ready to go or should we wait for further testing?

i should also note that this noise isn’t terribly loud on my setup. when i have a full piece with many voices running it’s not noticeable. it’s those quiet moments where it stands out. fine for live stuff, but not so much for recording.


i have the PCBs at the workshop but haven’t built one to test. conceivably they should work given they are so simple. i can also send you one when i get back (oh and hey i’m in the bay area!)

i like the idea of the external power source also being USB, because almost all USB power supplies (ie iphone etc) are two prong and very universal-- plus you could use a USB battery if desired for maximum isolation.

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@shellfritsch @benniii,

Sounds like if it’s a grounding issue the m05 silencer wouldn’t make a difference?

@tehn yeah this sounds promising. enjoy the bay!

@jasper_ryder without knowing what’s going on inside that m05 silencer it’s hard to say…

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well, if the m05 only fixes the 5v line, which the ansible doesn’t touch, i don’t think it’d help. would be good for trilogy modules.

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Hi! I am definitely in the boat where I get a nasty hum when I connect the grid to Ansible. To be honest, I almost wouldn’t notice it so much, but I can hear it hum when nothing is plugged in. I’d love to be able to perform, or even play really quietly without that tinnitus-esque feeling. My case is a TipTop Mantis, and it’s theoretically grounded, but I believe that none of the three-pronged outlets in my apartment are actually grounded. :zap:!

Does anyone have any suggestions for powering the grid separately to avoid this issue? The USB splitter seems like a good idea, but a nightmare for cable management.

i just learned about the aturia-made “anti ground loop adapter” from a friend with a beatstep pro. i guess the leds in the bsp have been known to bleed into the cv connections.

(y-cable on the left)

unfortunately it can only be purchased as part of a 4 piece replacement cable kit.
i haven’t tested this out with my grid, but seems like it could be an alternative for folks who don’t want to build the offworld adapter.

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