Metropolis Noise/Whine

Has anyone else experienced noise from their Metropolis throughout their system and fixed it?

I recently noticed it with mine and it’s audible anytime my eurorack case is connected to my mixer, even when the Metropolis is unpatched. The noise is in time with the Metropolis step LEDs and screen (it cuts in and out when the screen is on a menu that flashes it).

I’m using 4ms Row Power fwiw, and I get the noise even if the Metropolis is the only module powered up.

It is due to the ground impedance of the flying busboard. The 4ms power row and tiptop uzeus both manify this issue.

You could try moving the metropolis to the power connector closest to the power module. However I recommend getting a beefier power supply if you want to reduce noise in your system from all modules.

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Thanks for the quick reply.

I tested the Metropolis connected directly to the row power via its ribbon cable (no flying buses involved), and no other modules. I connected the metropolis pitch output to my mixer, with the channel fader all the way down. The noise still came through. I tried it with 3 different mixers, headphones and monitors.

Would your 30w power board help alleviate it, even though the amps are similar to the row power, or would I have to step up to the 80w version?

I switched my monitors to balanced cables. Not sure why that also affected headphones but now the Metropolis is quiet.

Sounds like some kind of electrical grounding issue. These can plague a lot of studios and are often hard to diagnose and solve! Balanced cables for monitors is always a good idea too…

I have the Metropolis in one of the Intellijel 4U 104HP cases and also have this exact issue. Balanced cables throughout my system as well. From my understanding, it’s not something that can be totally alleviated, but if there’s something else to try, I’m all ears…

I’ve got this weird whine too on my sequencer … tried swapping between output modules (Rosie and Pico), checking that I had clean power (I do) tried different cables and power sources to no avail … not terrible mind you, but I wish quiet meant quiet …

I have the same issues with my Metropolis, among other issues. I’m using Intellijel’s TPS80W bus board and Mean Well 90-Watt PSU. Really a bummer. Basically, I can patch things in any order, but as soon as I introduce the Metropolis into the chain, the hiss begins.

Just wondering if anyone has had any luck fixing this issue? I have two intellijel cases, a 7u 104hp performance and a 4u 104hp skiff. I’ve tried placing my metropolis in either case, as well as trying different quarter inch cables from my case to my audio interface.

This only seems to happen when I listen to audio out on my speakers but not on my headphones. I’ve included an image of my current setup in case moving things around might help. Any help is greatly appreciated. Thanks.

Have you tried connecting the case or speakers to different power outlets?

Do you have a power conditioner?

I will definitely try different power outlets. I’m using a surge suppressor power bar at the moment but don’t have a power conditioner specifically. Im going to be swapping out my surge suppressor power bar for a Furman SS-6B Pro Surge Suppressor tonight to see if that makes any difference, and will also be looking into power conditioners to see if I can remedy the issue. I can keep you posted on my progress.

I tried a Furman M-8x2 when I was having issues and nothing changed. For whatever reason, after trying everything else (even giving the Metropolis a separate power supply), only going to balanced cables between my mixer and monitors helped.

Thanks cables seems like the cheaper route to go before buying a power conditioner. I’ll likely start there first and see if I get any results.

I switched over to balanced cables and was able to eliminate a lot of the noise, not completely but a good start. My next steps are to move my speakers further away from my case (They share the same table), and maybe invest in better quality balanced cables and some sort of power conditioner.

Had the same problem with:-

  1. uzeus + bigger brick
  2. 4ms 40 + 90 W brick

Move it to one of my Doepfer cases and no noise.

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