I just got my Arturia RackBrute 6u. And there seems to be some ac leakage which, when go softly touch the front plates of my modules I can feel a buzz. I also suspect that it messes with my modules, my marbles clock input is super sensitive, and randomly fires if I plug a cable into it. And I can hear slight seemingly random pitch variations in my telharmonic, I use an ungrounded plug. Will changing to a grounded plug work? Or what should I do? I have tried with both the supplied ac adapter, and an ac adapter from my make noise skiff (which don’t have this problem)

Thanks


This sounds like a ground loop issue. The problem probably isn't coming from the RackBrute's DC supply, but from a grounding issue with whatever you have the RackBrute connected to. The fix is to consolidate all of your AC connections onto the same ground plane. Probably the best way to do this is to star-ground everything to a central point that has an AC ground, such as your mixer. To do this, simply connect hookup wire between all of your equipment chassis and get those connections back to your mixer, which may well have a ground post for this exact purpose.

The next possibility is that something internal in the RackBrute isn't properly connected, and you're getting DC onto the chassis from an improperly-connected bus cable. If the issue persists after establishing a star-ground, then I would suggest opening up the cab and checking the bus cables to see if everything is properly seated on the busboard headers. If this is the problem, I would suggest keeping the star-ground connected anyway, as a good unified ground also helps to reduce overall noise issues in your system.


Thanks for your reply :-)

The RackBrute is not connected to anything else!
I have tested the make noise skiff again, and it actually also exhibits this behavior, with only one module in it (with this module taken out of the RackBrute, the RackBrute feels buzzy). So unless it is multiple modules that causes this, it is not a module problem.

Further, if i touch the ring of the dc plug with one hand, withOUT it being connected to the RackBrute (so it is unpowered and not connected to anything) and touch the RackBrute with the other hand, is also buzzy feeling, as soon as I let go of the dc plug it stops


That's a bit alarming, actually. What I think you should do is to get a device such as this: https://www.homedepot.com/p/Gardner-Bender-Outlet-and-GFCI-Tester-GFI-3501/202867890 that works for your location's mains voltage and plug setup (if you're outside of North America) and then check your outlets to see if something's miswired. What you're describing certainly doesn't sound normal at this point, so I think that suspecting your AC circuits might be a logical next step.


I just got my Arturia RackBrute 6u. And there seems to be some ac leakage which, when go softly touch the front plates of my modules I can feel a buzz. I also suspect that it messes with my modules, my marbles clock input is super sensitive, and randomly fires if I plug a cable into it. And I can hear slight seemingly random pitch variations in my telharmonic, I use an ungrounded plug. Will changing to a grounded plug work? Or what should I do? I have tried with both the supplied ac adapter, and an ac adapter from my make noise skiff (which don’t have this problem)

Thanks
-- Palme

I had the same problem with the Rackbrute, I measured 110V AC (exactly halve the Current in Europe), I have contacted Arturia, and they explained that their gear should used in a grounded socket.
I needed to get my power from the kitchen, but I would not let this get me away from Modular.
For the RackBrute this was a solution but I am not sure this is a total solution, because I ask myself if this is doable in all live situations.
Also I found out that between the earthed RackBrute and the miniBrute is a almost 100 Volt AC difference, I bought another power source with an earthed power plug, but that did not help.
My solution now is to have a constant patch cable between my PNW (a clock port) en the MiniBrute (sequencer clock in).
Same problem was with the keystep, but that I do not use at the moment.
I have also a basic Doepfer case and I noticed that a lot of modules use the rails as ground, but in the doepfer case this is not earthed. So they build up a power difference most add between 10 and 15 volt to the rails, and that also leaks to the front panels.
So with 5 modules I already had around an 50 volts difference with earth, and felt shocks when i touched the panels.
To be honest it shocked me that this problem is not covered right in a lot of cases and modules, but for now I have learned to cope with it, hoping it will not trigger the electrical protection systems in my house.
I have put the PNW in the doepfer case, and have a permanent patch to a MI Links, and from the MI Links the patch goes now to the MiniBrute 2S.


FYI, if you're seeing 110 volts across these devices, then one of your voltage legs has a wiring fault. Power systems in Europe tend to use balanced power, which puts half of the total line voltage on each voltage leg. This sounds very much like one of the legs is going directly to ground, which is a serious -- and potentially dangerous -- problem. Again, I cannot more highly stress the need for ground fault testers to be part of any electronic musician's "must-haves", both for studio use and to check live venue power situations.


FYI, if you're seeing 110 volts across these devices, then one of your voltage legs has a wiring fault. Power systems in Europe tend to use balanced power, which puts half of the total line voltage on each voltage leg. This sounds very much like one of the legs is going directly to ground, which is a serious -- and potentially dangerous -- problem. Again, I cannot more highly stress the need for ground fault testers to be part of any electronic musician's "must-haves", both for studio use and to check live venue power situations.
-- Lugia

I do not know how it is in other countries, but here in the Netherlands we have 1 Phase : 220/230 Volt and a zero wire to the sockets, and another earth connection for 3 prones plugs.
In the 70-er years it was normal to have 2x 110 (even 127V i think ) phases to the sockets, but that only is normal in older parts of towns, but the modern houses have 0/220 wires..


That's sort of unfortunate, really...even though having balanced power can be a bit of a wiring hassle, balanced power = CLEAN power. I switched from having that same (more typical in N. America) single hot-leg setup to proper balanced 120 V some years ago, and the results were amazing. You could definitely tell that the noise floor in the studio had dropped, and because of the phasing done by the balancing toroids, various clicks and pops and other intrusive powerline garbage were totally eradicated. And all of my gear worked just fine on that balanced arrangement, as well. True, it's definitely a hassle to wire, because mistakes in wiring that sort of thing (floating grounds, especially!) can lead to a lot of problems that you normally don't see in unbalanced power circuits...but, again, the results were worth the trouble.


Ok, Thx, Lugia, (oh hope we did not steal this thread away from Palme).
First thing I have done is to buy a 'power tester' to be sure all earthed sockets in my kitchen are well wired or not.
Then I will try to find out what the possibilities here will be with your example in mind.