Static electricity in audio output?

Freak MicroFreak
#1

I got a microfreak that I was first using with headphones, and I just bought some speakers.
When I start connecting the audio cable to the microfreak output, there is immediately a strong static noise. When I unplug it it’s even worse, it makes some huge “crack” noise and I even got some static electricity discharge.

I’m using the provided adaptor with 3 plugs so it’s supposed to be on ground. I tried with 2 different TRS cables. I don’t have this issue using a different device connected on my speakers.

It it a known issue?

#2

I just made a test by connecting the audio output to my Digitakt audio input, and then the Digitakt output to my speakers and it’s the same: as soon as I plug in the microfreak power cable, even without switching it on, I hear a strong static noise.

#3

I am no expert but I think best practice is to turn the volume down on the amp/monitors (or have switched off), insert audio cables and then slowly turn up the volume.

Try that and see if the issue persists.

#4

Are your speakers powered by a 3 prong grounded plug as well? It might be a ground loop then. Try powering your microfreak through a usb cable plugged in a phone charger powerbrick.

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#5

It’s better if I connect with the monitors switched off, but as soon as I switch them on it’s very noisy and full of static.

#6

My speakers don’t have a ground plug (Presonus Eris 3.5).
Indeed if I power my microfreak through USB it seems to solve the issue! Even if I plug the USB cable directly into a USB adapter in the socket.

#7

HI @franky

Reading through this thread, it seems that either there is an issue with your power adapter you’re using to power the MF, or you have an issue with your mains supply.

@Funtmaster advice regarding powering up is VERY good advice which EVERYONE should follow to protect against damaging equipment in the chain, particularly speakers and power amps… SERIOUSLY, i cannot over state this enough!!!

Could you tell us EXACTLY what equipment you’re using and EXACTLY how you’re connecting it when the issue occurs, please.

HTH

Edit:

IF you are getting sparks, ‘static electricity’ etc from your system, you REALLY SHOULD get a QUALIFIED electrician to check your mains supply over as this should not be happening!

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#8

Thanks for your answer and advices.
I’m in a modern building (France) and never had any issue with my electricity supply.

It occurs when I use the microfreak with its provided power adapter, and connect its audio output to my speakers. I bought the MF second hand so I can’t guarantee that it’s the official power adapter, I could not find any info on the official Arturia adapter. It seems that they provide “no-name” power adapter so I would say it’s the original one. It has a “3 plug connector”, ie a ground connector.

My speakers are brand new Presonus Eric 3.5 that are powered through its original adaptor that has only 2 plugs (so no ground connector).

#9

Hey @franky

You should at least stop using that power supply for your MF and source a new one.
Just make sure it’s of the same polarity, and it can provide enough current to power your MF.
According to the manual, you can also use a USB power bank to power it.

HTH!

#10

I’ve noticed that my MicroFreak is noisy when it’s powered off, but it goes away when turned on. I’ve seen other reports of this, too. I think it’s a known issue with the hardware design. I always worked around it by muting the input it’s connected to when I’m not using it (or these days it’s usually not connected to my interface at all except when in use).

If you hear noise when it’s powered on, that’s a bigger problem.

One thing to be sure of, since it sounds like you’re connecting it directly to a speaker rather than an audio interface or mixer: the main output is a mono balanced TRS output, not a stereo output. You shouldn’t be trying to split it into two signals to send to left and right speakers. If using a TRS cable, it should be plugged into a mono balanced input.

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#11

Thanks for the remark on the cable. Indeed I was using a stereo → 2 x mono TRS cable, which was causing issue with the stereo mixing on my audio interface (Digitakt). I switched to a simple mono cable and it’s better. However I wonder how I’m supposed to send the mono signal directly to my speakers which only have 2 left and right inputs? At some point the mono signal needs to be replicated twice.

Also, my microfreak is also very noise when powered off (and powered through the provided power supply). The noise disappear when it’s powered on, but there is still a huge noise when I plug / unplug the audio output cable. I understand that it’s supposed to be done only when the speakers are off, however.

#12

HI @franky

Realistically, you have a couple of options, either use an audio interface/DAW setup or, get yourself some kind of mixer.
Plugging synths directly in to a pair of active monitors isn’t really ideal, as you’re discovering.
With either of the options above, you’ll be able to route mono signals to both channels at the same time just by keeping the pan pot in the centre of either the mixer or mixer in your DAW.

HTH!

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#13

I agree with Mat that your best bet would be to use an audio interface or a mixer in between the MicroFreak and the speakers. In that case, assuming that it has balanced inputs (most do) the ideal connection is a single TRS cable from the MicroFreak to a single input on the interface or mixer.

If that isn’t possible, a TS Y cable should be OK, for example:

If the speakers have balanced L/R inputs, you could also use a TRS Y cable:

If you’re not familiar with balanced audio signals, it’s designed to reduce noise and boost signal by sending a phase-inverted copy of the signal along with the original. If that doesn’t mean anything to you, it’s not super important, but just know that it helps reduce noise, especially for longer cable runs. It uses XLR or TRS cables, but it’s not a stereo signal, and trying to connect a stereo jack at one end to a balanced jack at the other won’t work. Both ends of the connection need to support balanced audio. It’s not something you see on all synths, but the MicroFreak does support it. When in doubt, a TS (mono) cable will always work.

As far as the noise when it’s powered off, unfortunately I think that’s just a normal flaw of the MicroFreak. It’s another good reason to use an audio interface or mixer that lets you mute the channel when it’s off. Otherwise, your best bet is to unplug it when it’s off.

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#14

Since you mentioned using a Digitakt as an audio interface, I just went and looked it up.

The original Digitakt only supports unbalanced TS connections.

The Digitakt II does have balanced inputs, so if you do have one of the new ones, using a TRS cable would be fine there (either a single cable to one of the inputs or a Y cable with TRS at both ends like the second one I linked to above).