MOD Dwarf background noise by power supply

Hi all,

got my new Dwarf today and tried unsuccessfully to get rid of intolerable background noise. :rage:

Searching this forum there were many solutions by just replacing the power supply with one without grounding. Same recurring problem since 2018. Solved by buying the cheapest power supply from Amazon!

Hello ModDevices - this is a new device, German quality, echt jetzt?

Question: any ungrounded power supply with 12V 2A and the right plug is ok?

Thank you!

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@rocavaco That is not a question of German quality, that is a question of German legislation. Sometimes a manufacturer in this country has to do things that are detrimental to its product, even though the probability of an incident is close to zero.

…and there are solutions for this problem, which you also have with other devices. Just browse the forum.

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I already bought a lot of products with ungrounded power supplies within the EU. Legally.

EU and Germany are not the same! For explanation: I am a German

You can ask to Greeks or Italians how true is that :smiley:

(Sorry couldn’t resist) :peace_symbol: :musical_note:

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…sadly it is… not in all aspects, but Germany can sometimes be annoying… this is true

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Ok, let’s take the issue of safety seriously. With this piece below between Dwarf output and Amp input the hum should be gone too, right? Made in Germany for use in Germany. Does somebody use it?

https://www.thomann.de/at/palmer_pli01_line_isolation_box.htm

I am using a cheaper Behringer hd400 which has two channels and costs one third.

https://www.amazon.it/dp/B000KUD2G4?ref=ppx_pop_mob_ap_share

I am also using a cable like this to power the dwarf with a quick charge enabled charger or even a powerbank

https://amzn.eu/d/bSWc37j

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Powerbank is an interesting choice too - what is the power consumption of the Dwarf?
Hopefully Moddevices can give hints and/or already tested products here?

IIRC the charger is rated 3A. So with a 10000mah charger you could assume to have more than a couple of hour.

On the other hand it depends on how many USB stuff you are powering

After hours(!) of forum reading I found a post of someone from MOD that the Dwarf is eating just about 600mA when just audio is connected. Others use a 1,5 A power supply. Looks like using the Dwarf with battery and without power line connection would be the most noise isolating option (and secure and not more expensive then good line isolation boxes).

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I use Cioks DC7 to power Dwarf - single output which has 500 mA at 12V and it works fine.

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In my experience there is a permanent background of digital noise. That background noise is permeated with a small “click” at regular intervals and digital artifacts are added to the signal when a control knob is turned.

I tested by connecting a zoom recorder to the outputs with in and out levels both set to 0 dB. Nothing connected to the inputs, no USB connected, and both power adapters with no ground connection.

The noise is also present with nothing connected except for headphones. In fact the headphones output introduces it’s own little sound, like a rapidly repeating flutter.

While testing I also made sure that there was no Ethernet over power active, just in case that was adding some funk to the power :joy:

In conclusion I am certain that aside from ground hum my mod dwarf unfortunately has some digital interference from within the device itself.

The good news is that I have had some success pushing the digital noise into the background by decreasing the output gain as low as it will go and running the input hot.

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This in now the solution - safe and noise free. Palmer Daccapo, a high quality device for just 20 Euro second hand. Can be used with the grounded Dwarf power supply and does a “correct translation” from the balanced line out to the high impedance unbalanced input of a bass amp.

It should really be noted on the MOD home page that some kind of signal isolation is needed when connecting the Dwarf with a guitar or bass amp. As can be read in this forum I’m by far not the only one with this experience.

BTW the Dwarf internal setting “compensate gnd loop” did not help a lot in my environment.

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Interesting discussion here! I have my dwarf powered from like one of these isolated power bricks. I still have a lot of digital noise when the USB cable is connected to my computer on a powered usb C hub. (where I put my macbook power supply in the hub.
I could solve this by either adding in a usb isolator or not have the macbook power supply in the hub but on the laptop directly.

So If you all are having noise issues I would recomend checking if the noise is still there when the dwarf is not connected to your computer via USB cable.

An ja I do agree that this is very annoying for a 500€ product.

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I plug my USB cable directly into the computer - no noise.
Windows PC with 4 USB ports :stuck_out_tongue:

Thank you for sharing your solution, that might help me. Coincidentally a couple months ago I was making an attempt to integrate the Dwarf into my band setup for a bass guitar and gave up after discovering that even an empty pedalboard would push noise into my amp. Being a Duo owner, I’m well aware of the noise struggles and I was about to call it quits on my MOD journey because the Dwarf is continuing the pattern of spending more time resolving tech / hardware quirks than playing.

Clinging to a thread of hope, I had another idea recently to try running a couple mics in for a combination of vocal and acoustic guitar processing. Alas, this was also too noisy, but I’m willing to give a bit of a pass on this one since mics need special handling and it’s not something MOD advertises explicit support for. So now I’m researching portable pre-amp solutions…

Finally, on a whim, I tried out a couple of the paid AIDA models (skeptically, because several I tried previously sounded like I was in a windy electrical storm), and they sound pretty great even with my “noisy” PRS pickups. I feel like I can tolerate the current output and likely improve with a little more levels adjusting.

To echo others, this whole topic feels like a minefield for users. I consider myself pretty technical and I’ve struggled a lot to get acceptable results, especially compared to the plug-and-play reliability of my HRPB where I’ve never experienced a hint of noise or static across numerous instruments, output to amps or PAs, and in different locations. One time with the Dwarf I mysteriously stopped getting any audio output into my PA speakers until I switched the cables for TRS (which I only thought of because of something I had seen mentioned in a recent forum post at the time).

I already use either a battery or a TruTone power brick for the Dwarf, and sometimes use a battery powered amp. I’m fortunate that I can afford to supplement my setup with other pieces of hardware if needed, so I’ll cling to the ledge a little longer.

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A few things that hep reduce noise for me:

  1. Using an external pre-amp and turning the input gain to it’s lowest setting
  2. Running the output to a small digital mixer using balanced cables
  3. Turning on the ground lift in the options.
  4. Don’t use the headphone out

I still get some noise but a lot less. I would be interested in exploring a different power supply option, something a little neater would be good for the pedal board - but I though it had to be 12v 2A, which is 24 watts (I think, please correct me if I’m wrong)

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Thanks for the tips! It seems like a decent pre-amp(s) might be a good addition then. One challenge is I’m trying to stay portable / battery-only, but maybe I’ll bite the bullet and get a Jackery or similar.

Using an isolated power supply or a battery might help even more for you - or even a different one than the factory provided, since those are notorious by now. Mine is close to quiet without the ground loop compensation, good enough for jamming and casual gigs

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I’ve changed recently powersupply to powrbank + myvolts + Cioks 4 (powered with powerbank) and this setup is dead quiet, completely no buzing and hum. The pedaloard has 3 drives plus DuoX. I’ve noticed that as someone noticed earlier Dwarf has some internal digital clicking, not so noticable, DuoX do not have that issue.

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