USB Noise

The Lounge General Discussion
#1

What’s the best way to deal with the noise from USB-powered devices?

I have a StarTech powered USB hub but that doesn’t seem to help. I have a decent ground loop isolator but it seems to sap some presence from any synth it is plugged into, and it doesn’t get all the noise, anyway.

For what it’s worth, the synth I’m wrestling with at the moment is a MicroMonsta 2. I’ve also tried to figure it out for an OP-Z and OP-1 with no luck. I’m running them through a Scarlett 18i8 as a basic mixer into a set of monitors.

How do people deal with the noise?

#2

I would say power it off a 5v PSU with a USB slot not anything attached to the computer the scarlett is plugged into.

OR

Use an isolator on the USB lead, not a ground lift on the audio input.

(this sort of will be fine if not using the USB for 3.0 data transfer - USB to USB Isolator Industrial Grade Digital Isolators with Shell 12Mbps Sp Y4K1 4894890008057 | eBay)

#3

Since I bought this little fella here, all digital noise issues are gone forever.

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#4

You know… Lyra-8 users pay a lot of money for that sound. :laughing:/s

I try to avoid anything USB powered.

If it is, like NTS-1 for example I’ll use it with a power adapter only, not connect it to a hub or anything else. That usually works for me.

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#5

I don’t usually have the Scarlett—or my powered USB hub—plugged into a computer. I am powering most of the USB devices from the hub, and even with no data connection there’s still a high-pitched whine when the MicroMonsta is plugged in.

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#6

oh, hang on though - are the speakers and the powered hub plugged into the same place? I guess this might not be ideal.

I still suspect the isolator might be the answer tbh.

but have you got a usb power brick you can power the Micromonsta off maybe? See if that solves it and it’s probably a big clue that it is a ground loop.

#7

I have a probem with my Waldorf plugged into the wall outlet simply because the power source is USB type B into the machine I assume. One thing I wonder is, is it confirmed the power supply itself is not the issue? Either the hub, or the hub’s power supply?

If the synth, the expesive isolators as mentioned, or I’m using a cheap DI box with a ground lift function and it works but you have to gain stage because everything gets very quiet and there’s still some noise at some frequency but it’s greatly improved. It’s just an Amazon bought Pyle brand single DI box which was around $11 on sale.

For what it’s worth, I have issues with power strips and power blocks with both plugs and usb power that when I have a few things going through them, they whine. Some are worse than others, or more power is needed to get them whining, I guess it’s the transistor? I don’t know.

A ground loop ususally sounds like DEE DEEE DEE DEE DEET, a power source whine is like EEEEEEEEEEEEEE. The power source whine is audible without headphones/speakers, the ground loop is heard in the audio chain as it is a different kind of issue, so part of determining the problem is knowing if it can be heard without speakers or headphones turned on.

I feel like this:

#8

They were not, but I did keep playing around and plugging the MicroMonsta into a Belkin USB adapter, then into my power strip. It’s the same power strip as the speakers, but that doesn’t seem to matter. The whine is gone.

As long as I don’t get another USB-powered synth any time soon I should be set.

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#9

somebody recommended this for m8 tracker usb noise issues.

works for me.

#10

I have this issue with my Typhon (well, who doesn’t). It’s powered from a fancy quiet USB hub with external power, I tried ADUM3160 isolators (doesn’t work with them, probably insufficient current).

Luckily, Dreadbox offer a solution: USB POWER/DATA splitter - Dreadbox Synthesizers

If you ask me, they should have put it in the box, given that it’s absolutely necessary.

#11

yeah ten bucks to buy and ten bucks to ship is bullshit, charge an extra 7 for the synth and just put it in the box.

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#12

Ground loop (USB noise) is normally caused by powering the devices from a different source - if you run them from the same power strip that should resolve the problem, as you’ve removed the loop.

This confuses me a little. How your USB powered device is powered shouldn’t have any impact on how it sounds (beyond unwanted noise), there’s a small chance you’re underpowering and that’s causing an issue but it seems a bit unlikely. You sure this isn’t just in your head?

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#13

Unless the outlet itself has poor grounding, but that’s a different sort of problem with a similar symptom.

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#14

He’s taking about an audio ground loop isolator, aka an isolating transformer on the audio path, most of which are not sonically transparent.

Dave Rat did a video at some point looking at which of them would null out against the source signal (e.g. weren’t changing the signal in transit), and iirc the Radial ones were the only ones he tested that were actually clean, but a few hundred euros per stereo channel stings a bit.

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#15

Ah my bad! Galvanic isolation is a bit different for sure I don’t have much experience with it - I don’t think that’s an effective way to quell USB noise though (that I understand) so maybe a wasted effort - I guess it depends a bit on where/when you’re isolating.

I solved my USB issues by buying a bigger power strip :slight_smile:

#16

It depends on the device. I’ve got synths that need isolation on the audio side even if they’re feed clean power, and some that only need it on the USB side. The MM2 is notably bad, to the point where the designer specifically suggests that you need a USB isolator with it with almost any USB power supply — to keep costs low and reduce size, there’s no isolation on the power line at all.

Personally, I’ve been planning on grabbing a Cioks pedal power supply and building a set of low noise voltage regulator cables to take 9V 660mA pedal output and turn it into truly clean, isolated 5V 2A power, and then eventually look at MIDI ground lifts in places where that isn’t enough.

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#17

The “plugged into different power sources” was what I was (really unclearly) getting at.

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#18

Funnily enough the worst device I have for USB noise is my Oxi One and it doesn’t even handle audio! If I’m not powering it from the right place it leaks noise into my euro system something rotten, I guess through modules that aren’t AC/DC coupled.

It’s a horrible noise and I’ve ruined recordings with it (and only noticed when mastering). I don’t mind a regular noise floor, that’s just character :slight_smile: