I have recently bought a seven-year old M-Audio Keystation Pro 88, and noticed that when I plug it into my MacBook Air, I get static noise when I press keys.

Once pressed, the same key makes a cracking sound and then works fine. But static noise may reappear later on the same key or when I play chords.

Have anyone had a similar problem? Is it due to hardware and cords or the controller needs a clean up?

Any suggestions are welcomed.

PS: I'm asking this question here according to the Help Center that allows asking questions about "usage of specific music software or hardware".

  • What audio interface are you using? Are you just using the built in output? Is the MacBook plugged into power or running on battery? Is the keystation being bus powered? Commented Jun 20, 2016 at 12:24
  • @ToddWilcox (1) USB for both data and power, (2) I tried built in speakers and several headphones, (3) I tried both on battery and into power, (4) Yes, bus powered. Commented Jun 20, 2016 at 12:58
  • 1
    Sounds like the keystation is old and finicky. I have an older keyboard that has ground loop issues when I plug in both audio and MIDI which causes clicking noises whenever I press a key, but you can't really have a ground loop when nothing is plugged into power. The only other thing I could think of is using an external audio interface, but if you don't have one already that's an expensive option that might not even fix the problem. Commented Jun 20, 2016 at 13:07

1 Answer 1


I solved the problem. The solution is trivial:

Restarting the App

In my case, GarageBand.

With many apps open, Mac moves some apps from RAM to SSD. When a user presses a MIDI key for the first time, Mac moves the respective sound from SSD back into RAM. Which takes time and causes the cracking sound. Same for long notes and chords (they seemingly has different sounds).

Restarting the app ensures that it's entirely in RAM for now. And no cracking sounds.

(Optional) A USB cable with ferrite bead

A friend of mine recommended a USB cable with a ferrite bead (cylinders on both sides of the cable) to ensure that the cable collects no static noise from the environment.

That seems to be relevant for many noise-related issues.

  • This is a latency problem: check your audio/midi buffer settings etc. in garage band. The static noise from usb thing is a red herring: it may be true for analog, but not for usb.
    – Yorik
    Commented Jun 22, 2016 at 20:39

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