Crackling when recording guitar

I have an issue.
Please check the video I linked to below so you have hear + see my problem.

I don’t know what could be the issue here. I checked the cables, guitar, pedal. My only conclussion is that it might be the mixer I use.

I am using the latest version of OS X
And the software I use in the video is Cubase Artist 6. However, I tested it in Audacity aswell, which didn’t work either

I’m guessing a hardware problem.
What happens if you unplug the guitar and use a different sound source?
Try to trace the signal path through from guitar to computer to narrow down where the problem starts.

I did. I traced it back to either the software, or the mixer

So what is the make and model number of the mixer?

The latest OS X is 10.9.1 (please always give exact version numbers).

Does the mixer have correct drivers or firmware for 10.9.1?


Does the mixer have a headphone socket? If so, do you hear the crackling if you listen through headphone into the mixer?

The mixer seems to be perfectly happy with it’s green flashing lights, but the computer sound levels are to-the-moon too high. There are “normal” things that people do wrong when they connect things to a computer, but this is even far worse than that.

How are you getting into the computer? I don’t see anywhere you tell us. Newer Macs no longer have a Stereo Line-In like the older ones did and you’re stuck with an adapter.

This is what I use and it works with both Macs and Windows.

That’s a Behringer UCA202.

My Macs were bought because they have Stereo Line-In (circle and black arrows).


The mixer is a 3-Channel Audio Mixer. Stage Line MMX-512USB

I connect it via USB to the computer.

It does have headphone-input, but I need a jackcable to my headphones to use it

Close Audacity.
Apple (Upper Left) > System Preferences > Hardware > Sound > Input. Make sure your USB device is selected and see if a rational number of lights in the blue ball light meter flash when you play music. They should not all come on and stay on.

The USB connection may not have any provision to change the volume. This is probably normal.

Did you get it that far?


I did what you said. And all the blue balls are lit, all the time.

The USB connection may not have any provision to change the volume. This is probably normal.

I don’t understand this

OS X USB audio support doesn’t usually come with the ability to change the input level of the device in the system sound preferences. It depends on the device, but for most devices that’s the case. Since your device users the Core Audio USB drivers that come with Mac, it almost certainly is the case.

Have you read the Manual for the device ?

Does the mixer manufacturer offer e-mail support for the device?

Have you tried different Audio to buffer settings in the Audacity Recording Preferences?