Continuous white noise on left channel since update audacity 3.7.3

[wigl]

Hello!
I recently updated audacity to 3.7.3 since then I have a continuous white noise on the left channel as soon as I start the recording. My first thought was my micro (Rode NT USB) is broken or the cable. Both is replaced by a new product - the noise remains. I tried it on different windows computers, also in work - the noise remains. I tried different micros - the noise remains. The company which checked my micro uses audacity 3.7.0 - the noise does not appear.

So the only possible conclusion is: there is a bug with audacity 3.7.3 introduced - are there any similar experiences? Where can I submit bugs?

I uploaded a screen shot so that you can see what I mean.

Thanks for any help, best wishes, Herwig

[DVDdoug]

Noise is an analog problem, most likely it’s from the preamp inside the microphone.

But you can try an older version of Audacity.

Also, make sure Windows “enhancements” are turned OFF. They can cause all kinds of weird problems and there’s a slight chance that there is automatic gain control turning-up the volume when there is little or no sound.

And check Windows Microphone Boost because that will boost the noise as well as the signal.

There is always SOME noise from analog electronics and since preamps have lots of gain, the noise gets amplified.

Rode has a good reputation but perhaps your mic is defective.

And of course there is acoustic noise in the room. In a “soundproof studio” the acoustic noise is often worse than any electronic noise.

If it’s a high-pitch “whine” it’s probably noise from the USB power getting into the preamp. USB power is notoriously noisy (not a problem for digital). Some computers are worse than others and some USB mics or USB-powered interfaces are better filtered than others so it can vary a lot.

You can try a powered USB hub, or there are USB isolators, but if you get one make sure the power is isolated (which means the power is “re-generated” and there is no “direct” power or ground connection between the computer and USB device).

[wigl]

Dear DVDdoug,
thank you very much for your answer and hints.

I can definitely prove that the noise is caused by Audacity, due to the following facts (see also my original posting):

• I installed an older version of audacity now - 3.7.0 - and there is no noise on the left channel (see the uploaded screenshot of my original posting to understand what I mean).
• I install audacity 3.7.3 - and there is a noise on the left channel
• I tried it with two different microphones on 4 different PCs - always with audacity 3.7.3 - the noise is there
• I replaced my RODE micro with a completely new one - the noise is still there

So sorry, but when looking at the facts above it can in my eyes only be the SW audacity itself, and there the version 3.7.3 - which causes this noise. Also it cannot be any windows enhancements - because when I use audacity 3.7.0 and do not change anything - the noise is gone.

So there is a bug in audacity 3.7.3. - I cannot see any other possibility. I also checked now other versions, the bug appears since version 3.7.2, until 3.7.1 I do not get any noise on the left channel.

Thanks and best wishes,
Herwig