Help! Blue Yeti high pitch noise

[kozikowski]

That's a finished isolator. Been there, done that. The HiFimeDIY isolator we bought for $30 has no serious provision to keep hash on the supply lines away from the USB device (microphone, etc). All it does is make sure you don't fry yourself if your USB device accidentally "goes hot" several hundred volts against the computer, typically in industrial applications.

If you find something, it should have provision to plug in a power supply that has nothing to do with the computer like that circuit board.

"Apply 6v to 25v here."

Koz

[cyrano]

The exact same board from your link is available from Chinese sellers for about half the price. Free shipping. There is nothing special about the schematic, as it is an application note from Analog Devices.

I've also found a rough design for a USB 2 isolator. Looks that will cost a bundle. It needs 8 isolator chips @ 12.50 $ each and a Parallax FPGA @ 30 $. Add a board and some smaller components and you're at a price level of 200 $ at least for the hardware. And you still need software for the FPGA. Looks like I won't be doing any of those...

[kozikowski]

Data and high voltage isolation is completely beside the point here. The goal is to filter the USB power supply lines or substitute a different power supply altogether. USB isolators assume everything is working OK except the user is going to get killed because of accidental high voltage leakage. In our case, everything is not OK and high voltage is irrelevant.

Koz

[cyrano]

There are two main causes for USB interference:

- A groundloop over USB. That can usually be fixed with a ground isolator. I've never tried this particular isolator, because, as you said, they are mainly for over voltage protection in industrial environments. This shouldn't be present if the laptop is on battery power.

- A whine from the voltage converter inside the mic, usually caused by a thin USB cable, bad design or a weak USB power supply. Condenser mics need a polarizing voltage and there's a circuit that converts the 5V to 60V (or even higher) inside the mic. These work on frequencies of 40 KHz or higher and if the circuit isn't getting enough current, they will produce an audible whine because they start oscillating. This happens when the 5V from the USB port gives in. The converter stops, the 5V rises again and the converter starts again, making the 5V cave in again. And this oscillation happens on an audible frequency.

I'm beginning to suspect that the Blue Yeti has a weak power converter...

Having a separate power supply on the USB isolator would be a big boon. But you can also use a powered hub after the isolator. And have we tried a shorter/thicker USB cable?

[steve]

I think the suppliers are depending on the Yeti users not talking to each other.

"Does your Yeti fail ACX AudioBook because of that whiney noise? Mine does, too!"
"Hey, wait. Mine does that!!"
"No foolin'? I wondered about that stupid noise."

And etc.

One thing to remember is that laptop PC power supplies are notorious for creating electrical noise. Typically they are cheap switch-mode devices. Power supplies for Macs, costing many times the price of a typical PC psu, may be better (I've not tested),

If the interference is coming from the laptop psu, then simply running on batteries when recording should 'solve' (avoid) the problem.

[kozikowski]

Having a separate power supply on the USB isolator would be a big boon. But you can also use a powered hub after the isolator. And have we tried a shorter/thicker USB cable?

It's the only boon so far, and you left one out. The 1KHz data management signal inside the USB cable is a majority of that trash. Our understanding of this is there is no power converter. The whole microphone is running from the USB 5V line. The devices with actual power converters and filtering like the Shure X2U simply don't have the problem.

I got my interference sample with no cable. The device plugged directly into the computer. We have a long history of solving this problem. You can change any condition and the problem changes, but never goes away. Flynwill's technique was the only method that made the problem go to zero and stay there

Yes, an externally powered hub seems to be the get out of jail card, but we stopped recommending that when people found hubs so cheap they would pass on AC power noise and/or passed on the original USB noise anyway. Most AC powered hubs will default to USB power when the AC goes away, and the leakage in the switching system is enough to kill this solution.

So far the only way to solve this is to make the microphone 5v effectively independent of the computer.

Koz

[edised]

Hi Yeti Users!

I have got the same problem on a standard Yeti.
I don't think this has to do with USB power as the mic should be designed to work with ANY usb power, considering it is ... a USB mic!!!
It is more a design fault or a unit fault, considering a lot of people have the same problem, I would go more for a design fault.

What I have noticed is, if I plug the USB cable on my laptop and listen straight away to the signal through my headphones, the sound is fine. As soon as I select the Yeti as source from the software prefs, or even in the system preferences the high pitch noise starts! Same thing on my wife's macbook!

I have been in touch with Blue and sent them a sample and they have agreed to test and replace my mic.
So they must know it's a fault and I don't believe that you need extra shielding, hubs or whatever to make this work!
I also have a Zoom H1 that I am using with the same usb cable, same laptop, and it always been dead quiet!
So hopefully a replacement will do the trick!

Has anybody sorted this problem with a replacement yet?

[kozikowski]

I've never heard of a USB MicPre and analog microphone exhibiting this noise. The feature of providing 48v to a condenser microphone means the MicPre has power processing and that seems to be the solution. I have a Behringer UM2 MicPre and C1 microphone under test. They may have other shortcomings, but Yeti Curse noise isn't one of them.

Once you get beyond the whine problem, you may find an occasion pop or snap in the show. Goodness knows where that's coming from. This is the current testing

USB MicPre and analog microphone (and a Mac) is the configuration ACX AudioBook recommends (with much more expensive MicPre and microphone).

Bottom feeding seems to be a common thread running through all these complaints. USB microphone is the cheapest way to do voice capture short of a laptop built-in microphone. But it doesn't always work.

Also under test is a stand-alone sound recorder that doesn't have any USB sound problems because there's no USB connection or computer during the performance.

Koz

[TheTalkingKeyboard]

Uhh... Hi everyone.

This post is pretty old, and I'm surprised I've never found it within the almost 3 years I've had these problems with my Yeti.

In a nutshell, I've got the exact same problems as everyone else, except to a lesser extent: Mine is exceedingly quieter. I didn't get to listen to some of the audio examples due to their time on that website expiring, although some examples are still present, thankfully.

Did anyone manage to fix this? Are there any other posts where this has been fixed? I've had this problem for years and this is the only time I've found anything similar to what I have.

Thanks
-TTK

[Gale Andrews]

In a nutshell, I've got the exact same problems as everyone else, except to a lesser extent: Mine is exceedingly quieter.

Than have you tried Noise Reduction on the noise?

You can attach an audio sample of your noise if you like.

Have you considered getting a better mic?


Gale